Strange 12-bolt install
12-12-2004 | 10:30 AM
#1
Thread Starter
Joined: Dec 2001
Posts: 4,908
Likes: 3
From: Cleveland, OH
Strange 12-bolt install I found this in my archives from 2001; thought it might be useful.
-----
STRANGE 12-BOLT INSTALL
This will help you learn more about the Strange 12-bolt rear axle assembly, including what it is, what it can do for you, and how to install it.
The following procedures are what worked for me. They involve activities that can be dangerous and possibly fatal. I offer this information only to document what I did. I assume no responsibility for the consequences of your actions. I assume no responsibility for damage to your car, your property or injuries to your person or any other person. I strongly recommend that you assure yourself you possess the capabilities and knowledge to perform these procedures.
And, I strongly recommend that you follow sound, safe, working procedures to prevent injury to yourself and others. Never work on a car supported by a jack – use sturdy jack-stands, positioned under the proper structural members of the vehicle. Use the required protective devices…mechanic’s gloves, eye protection and a mask when grinding or working around brake pad dust.
Background:
The factory 7.5/7.625-inch rear axle assembly is weak. Some of them seem to stand up to severe use, e.g. Joel Stein has managed to run in the 10’s, with 1.5x 60-foot times, and others fail under street use. To avoid the possibility of failure, and to allow you to get the maximum performance out of your car, you really need to upgrade to a stronger assembly.
There are two choices here – the Ford 9" rear and the GM 12-bolt. This is the first choice to make. The Ford 9" has a number of advantages, including:
Low cost
A drop-out pumpkin, allowing quick gear changes
Indestructible.
But it seems to have a few drawbacks too:
No plug-and-play setups available, all seem to be "some assembly required"
The pinion is located further below the axle centerline (2.25" vs. 1.50" for the 12-bolt), offering the potential for pinion angle setup problems. This is also contributes to the next problem.
It has a higher internal friction loss. Published data indicates the GM 12-bolt has an efficiency of 93%, about 3% higher than the Ford 9" which is 90%. In a 500HP setup, this will cost you 15HP. (Ref: National Dragster, 11/10/99, "What’s The Diff?" by Bruce Dillishaw)
No ABS available.
It’s made by Ford.
So that got me past the Ford 9". I wanted ABS, I wanted a ready to install unit, I like to keep my car "all GM", I don’t want to lose HP..
Within the GM 12-bolt community, there seems to be two choices…the KTRE or Strange units. I have heard several horror stories about the KTRE unit, including 6-month deliveries, charging your credit card for the full amount and holding the money for months before shipping, refusal to refund when delivery is unreasonably delayed. The technical quality of the unit appears to be satisfactory. They just appear to be a very small company with limited resources, and no sense for business.
For the Strange Engineering unit, I have heard nothing bad, and my own experience with Strange has been mostly positive. I knew it would hold up to the engine I was planning. My buddy, George Baxter (30th Anniversary SS Convertible) had been using the Strange 12-bolt, with 3.42 gears in his 720 RWHP car. That convinced me it was rugged. George’s posi clutches did burn out about the time he mod’d over 700 RWHP, and he found out he had bought an assembly with a "standard" posi unit. He replaced it with a version of the heavy-duty unit, and that solved the only problem he had run into. This told me I needed to go with the heavy-duty posi from the get-go. Word is the heavy-duty unit will chatter in normal turns. (comments to follow xxxxxxxxxx)
Specifications/Options:
Here is the info on the Strange Engineering "12-bolt Rear End ‘Bolt-In’ Replacement for F-Body Cars" (note: Strange spec sheets show the "racer net" for the standard unit with ABS as $2,285):
The unit is available for 3rd gen. (early) or 4th gen. (late). The difference is that the 3rd gen. rear axle assembly is 3-inches narrower than the 4th gen. assembly. And the 3rd gen. has ½" wheel studs, while the 4th gen. has 12 mm x 1.25 metric studs. You need to specify "early" or "late" in the order. The 4th gen axles actually come with two sets of stud holes, so they can accommodate 12mm or ½" screw in studs.
It will accommodate both drum and disc brakes. You need to specify in the order.
Strange designed 12-bolt case, with torque arm (TA) provision. The relief cut for the TA fits the stock TA fine, but may require grinding of the TA bracket on some aftermarket TA’s.
Fully welded tubes. They are similar to the OEM tubes in diameter, and allow use of the OEM U-bolts for the sway bar attachment. The tubes measure 2.625".
Direct bolt-in (see my install for a few clarifications!).
Chrome-moly caps.
LPW aluminum cover with pre-load bolts, fill and drain plugs
33-spline axles.
U-1602 yoke, with cross-over U-joint. You need to specify what driveshaft you are using so they can supply the correct u-joint. OEM steel driveshaft uses Precision #447; OEM aluminum shaft uses #348. The U-joint is sent separately via UPS
3.150" housing ends, eliminating c-clip axles.
Optional ABS sensor. You need to read the published literature very carefully. The standard and optional carriers include the ABS reluctor ring. The ABS sensor is included as standard. See my unfortunate experience, below.
The disc brake caliper mounting brackets have provisions for the traction control (if you have it) wheel sensors/pick-up ring, but you need to reuse your factory units.
Option:
Super-strength Posi unit - $325. The base unit has 9 clutch discs in the Posi unit. The Super-Strength has 14 clutch discs. It includes a welded-in ABS reluctor ring. Be sure to specify this clearly in your order. See my problems below.
-----
STRANGE 12-BOLT INSTALL
This will help you learn more about the Strange 12-bolt rear axle assembly, including what it is, what it can do for you, and how to install it.
The following procedures are what worked for me. They involve activities that can be dangerous and possibly fatal. I offer this information only to document what I did. I assume no responsibility for the consequences of your actions. I assume no responsibility for damage to your car, your property or injuries to your person or any other person. I strongly recommend that you assure yourself you possess the capabilities and knowledge to perform these procedures.
And, I strongly recommend that you follow sound, safe, working procedures to prevent injury to yourself and others. Never work on a car supported by a jack – use sturdy jack-stands, positioned under the proper structural members of the vehicle. Use the required protective devices…mechanic’s gloves, eye protection and a mask when grinding or working around brake pad dust.
Background:
The factory 7.5/7.625-inch rear axle assembly is weak. Some of them seem to stand up to severe use, e.g. Joel Stein has managed to run in the 10’s, with 1.5x 60-foot times, and others fail under street use. To avoid the possibility of failure, and to allow you to get the maximum performance out of your car, you really need to upgrade to a stronger assembly.
There are two choices here – the Ford 9" rear and the GM 12-bolt. This is the first choice to make. The Ford 9" has a number of advantages, including:
Low cost
A drop-out pumpkin, allowing quick gear changes
Indestructible.
But it seems to have a few drawbacks too:
No plug-and-play setups available, all seem to be "some assembly required"
The pinion is located further below the axle centerline (2.25" vs. 1.50" for the 12-bolt), offering the potential for pinion angle setup problems. This is also contributes to the next problem.
It has a higher internal friction loss. Published data indicates the GM 12-bolt has an efficiency of 93%, about 3% higher than the Ford 9" which is 90%. In a 500HP setup, this will cost you 15HP. (Ref: National Dragster, 11/10/99, "What’s The Diff?" by Bruce Dillishaw)
No ABS available.
It’s made by Ford.
So that got me past the Ford 9". I wanted ABS, I wanted a ready to install unit, I like to keep my car "all GM", I don’t want to lose HP..
Within the GM 12-bolt community, there seems to be two choices…the KTRE or Strange units. I have heard several horror stories about the KTRE unit, including 6-month deliveries, charging your credit card for the full amount and holding the money for months before shipping, refusal to refund when delivery is unreasonably delayed. The technical quality of the unit appears to be satisfactory. They just appear to be a very small company with limited resources, and no sense for business.
For the Strange Engineering unit, I have heard nothing bad, and my own experience with Strange has been mostly positive. I knew it would hold up to the engine I was planning. My buddy, George Baxter (30th Anniversary SS Convertible) had been using the Strange 12-bolt, with 3.42 gears in his 720 RWHP car. That convinced me it was rugged. George’s posi clutches did burn out about the time he mod’d over 700 RWHP, and he found out he had bought an assembly with a "standard" posi unit. He replaced it with a version of the heavy-duty unit, and that solved the only problem he had run into. This told me I needed to go with the heavy-duty posi from the get-go. Word is the heavy-duty unit will chatter in normal turns. (comments to follow xxxxxxxxxx)
Specifications/Options:
Here is the info on the Strange Engineering "12-bolt Rear End ‘Bolt-In’ Replacement for F-Body Cars" (note: Strange spec sheets show the "racer net" for the standard unit with ABS as $2,285):
The unit is available for 3rd gen. (early) or 4th gen. (late). The difference is that the 3rd gen. rear axle assembly is 3-inches narrower than the 4th gen. assembly. And the 3rd gen. has ½" wheel studs, while the 4th gen. has 12 mm x 1.25 metric studs. You need to specify "early" or "late" in the order. The 4th gen axles actually come with two sets of stud holes, so they can accommodate 12mm or ½" screw in studs.
It will accommodate both drum and disc brakes. You need to specify in the order.
Strange designed 12-bolt case, with torque arm (TA) provision. The relief cut for the TA fits the stock TA fine, but may require grinding of the TA bracket on some aftermarket TA’s.
Fully welded tubes. They are similar to the OEM tubes in diameter, and allow use of the OEM U-bolts for the sway bar attachment. The tubes measure 2.625".
Direct bolt-in (see my install for a few clarifications!).
Chrome-moly caps.
LPW aluminum cover with pre-load bolts, fill and drain plugs
33-spline axles.
U-1602 yoke, with cross-over U-joint. You need to specify what driveshaft you are using so they can supply the correct u-joint. OEM steel driveshaft uses Precision #447; OEM aluminum shaft uses #348. The U-joint is sent separately via UPS
3.150" housing ends, eliminating c-clip axles.
Optional ABS sensor. You need to read the published literature very carefully. The standard and optional carriers include the ABS reluctor ring. The ABS sensor is included as standard. See my unfortunate experience, below.
The disc brake caliper mounting brackets have provisions for the traction control (if you have it) wheel sensors/pick-up ring, but you need to reuse your factory units.
Option:
Super-strength Posi unit - $325. The base unit has 9 clutch discs in the Posi unit. The Super-Strength has 14 clutch discs. It includes a welded-in ABS reluctor ring. Be sure to specify this clearly in your order. See my problems below.
Last edited by Viper; 12-15-2004 at 07:07 PM.
12-12-2004 | 10:31 AM
#2
Thread Starter
Joined: Dec 2001
Posts: 4,908
Likes: 3
From: Cleveland, OH
Order/Shipping:
I checked around and decided to place my order through T. Byrne Motorsports. Tom is a straight-shooter, and totally reliable. You can check around, or you can deal direct with Strange. I had a set of gears/install kit/aluminum rear cover to return to Tom for credit, so this was the best deal for me.
Please note that shipping is quoted as "freight collect". It comes on a truck, not UPS, and you may have to pay for shipping when it arrives. I was supposed to pay on receipt, but the shipping papers were marked "prepaid". I settled up direct with T. Byrne. The shipping cost was $190.50 (ouchhhh).
I ordered the unit from T. Byrne on 9/14/99. He quoted me 4 to 5 week delivery. I received it on 10/14/99. That’s reliable info!! It arrived mounted in a sturdy wooden shipping frame, with two clamps holding the unit on the frame. It had an invoice, and a copy of the shipping papers, but no "instructions". The warranty was printed on the bottom of the invoice. I faxed Strange for some instructions. Not to find out how to install it (that seems pretty obvious), but what lube to use, break-in procedure, lubricant change frequency, and the factory setup, e.g. backlash and pinion depth. They responded:
"Your housing is filled with Pennzoil SAE 80W-90 GL-5 and GM Limited Slip Additive #1052358. Your backlash is set at 0.10". No break-in is required. All housings are pre-run before shipping. Follow your stock service requirements."
Preliminary Activities:
The trucker unloaded the unit to the driveway. I removed the shipping clamps, and he helped me move it into the garage (this seems to be up to the driver, it netted him a nice tip!). The trucker kept the wooden shipping frame. You might want to keep it, just in case you have to send the unit back, or to ship your old factory unit. The Strange axle assembly weighs 162 pounds, equally divided between left and right sides, according to my bathroom scale. I just put it on the floor, with wood blocks under the shock brackets, and another block under the panhard rod bracket to keep it level. Then I stood and looked at it. It is a very nice unit. Fab quality looks very good. Butttttt, it was not painted. The axle hubs are coated, and the brake caliper mounting brackets appear to have a black anodized-like finish, but the tubes, housing and brackets are all unfinished steel or cast iron. Of course the LPW cover is aluminum.
I decided to paint it, so it would not become rusted and ugly like my factory unit. I got some TSP (XXXX) grease remover, some Rustoleum premium (XXXXX) gloss black paint for the tubes, and Rustoleum (XXXXX) hammer finish silver paint for the center section. I washed it off with the grease remover and water, dried it real well, and ground of a small amount of weld spatter and some rough edges. The blue RTV they used on all the bolted, mating surfaces needed to have the excess cut away with an X-acto knife. Then I used the spray bombs on it (outdoors of course). This made for a very good looking unit.
I think it is a good idea to measure the stance of your car before you start. Measure the height of the rocker panels, in back of the front wheels, and in front of the rear wheels, the distance between the tops of the tires and the lower edge of the fender wheel openings, and the distance between the inside edges of the tires and the LCA’s. This will help you know if you have made any significant changes to the stance of the car with the axle install. This might help you track down any install errors. I was also installing the lowering springs, so I wanted to know where I started.
I checked around and decided to place my order through T. Byrne Motorsports. Tom is a straight-shooter, and totally reliable. You can check around, or you can deal direct with Strange. I had a set of gears/install kit/aluminum rear cover to return to Tom for credit, so this was the best deal for me.
Please note that shipping is quoted as "freight collect". It comes on a truck, not UPS, and you may have to pay for shipping when it arrives. I was supposed to pay on receipt, but the shipping papers were marked "prepaid". I settled up direct with T. Byrne. The shipping cost was $190.50 (ouchhhh).
I ordered the unit from T. Byrne on 9/14/99. He quoted me 4 to 5 week delivery. I received it on 10/14/99. That’s reliable info!! It arrived mounted in a sturdy wooden shipping frame, with two clamps holding the unit on the frame. It had an invoice, and a copy of the shipping papers, but no "instructions". The warranty was printed on the bottom of the invoice. I faxed Strange for some instructions. Not to find out how to install it (that seems pretty obvious), but what lube to use, break-in procedure, lubricant change frequency, and the factory setup, e.g. backlash and pinion depth. They responded:
"Your housing is filled with Pennzoil SAE 80W-90 GL-5 and GM Limited Slip Additive #1052358. Your backlash is set at 0.10". No break-in is required. All housings are pre-run before shipping. Follow your stock service requirements."
Preliminary Activities:
The trucker unloaded the unit to the driveway. I removed the shipping clamps, and he helped me move it into the garage (this seems to be up to the driver, it netted him a nice tip!). The trucker kept the wooden shipping frame. You might want to keep it, just in case you have to send the unit back, or to ship your old factory unit. The Strange axle assembly weighs 162 pounds, equally divided between left and right sides, according to my bathroom scale. I just put it on the floor, with wood blocks under the shock brackets, and another block under the panhard rod bracket to keep it level. Then I stood and looked at it. It is a very nice unit. Fab quality looks very good. Butttttt, it was not painted. The axle hubs are coated, and the brake caliper mounting brackets appear to have a black anodized-like finish, but the tubes, housing and brackets are all unfinished steel or cast iron. Of course the LPW cover is aluminum.
I decided to paint it, so it would not become rusted and ugly like my factory unit. I got some TSP (XXXX) grease remover, some Rustoleum premium (XXXXX) gloss black paint for the tubes, and Rustoleum (XXXXX) hammer finish silver paint for the center section. I washed it off with the grease remover and water, dried it real well, and ground of a small amount of weld spatter and some rough edges. The blue RTV they used on all the bolted, mating surfaces needed to have the excess cut away with an X-acto knife. Then I used the spray bombs on it (outdoors of course). This made for a very good looking unit.
I think it is a good idea to measure the stance of your car before you start. Measure the height of the rocker panels, in back of the front wheels, and in front of the rear wheels, the distance between the tops of the tires and the lower edge of the fender wheel openings, and the distance between the inside edges of the tires and the LCA’s. This will help you know if you have made any significant changes to the stance of the car with the axle install. This might help you track down any install errors. I was also installing the lowering springs, so I wanted to know where I started.
Last edited by Viper; 12-15-2004 at 07:07 PM.
12-12-2004 | 10:33 AM
#3
Thread Starter
Joined: Dec 2001
Posts: 4,908
Likes: 3
From: Cleveland, OH
Remove old unit:
I was doing a lot of stuff at once, so this might affect the remove and replace procedures. I had the following to install, in addition to the Strange:
Baer "enhanced" rear brake package. Basically, a larger (11.7" x 0.80") drilled, slotted and zinc-washed rotor, using the OEM caliper. It also includes braided S/S hoses, but I did not do the hoses. One less complication, and I wanted to wait until I did the front brakes to change the fluid and bleed the system.
HAL 12-way adjustable shocks.
Eibach Pro-Kit springs.
Air Lift air bags.
I already had the following items installed, which connected to the OEM axle assembly:
Just Suspension box-section lower control arms.
Just Suspension adjustable panhard rod.
Spohn adjustable torque arm.
Energy Suspension polyurethane bushings on the LCA’s, panhard, and sway bar, plus sway bar end links.
Since all these had been added in the past nine months, the bolts were all relatively rust free, and easy to loosen.
In the future, I hope to replace the OEM steel driveshaft, but not until I have the HP to render the stock unit useless. I really want the carbon fiber driveshaft, but it is very expensive.
Loosen the rear wheel lug nuts.
Check the brake fluid level in the brake master cylinder. If it is full, remove some fluid, so when you compress the rear calipers to remove them, the reservoir will not overflow. Be careful – brake fluid is instant disaster on your paint.
Raise the rear section of the car. I pulled my car into my garage nose first, put my ramps under the rear wheels, and my 4-inch "booster" boards (stacked, staggered 2x10’s) under the front. Backed it up on the ramps. Before you do anything, put chocks under the front wheels, front and back. Eventually, you will have no driveshaft and no emergency brakes to hold the car.
Raise it another 6-inches or so with a floor jack under the axle and put jack stands under the sub-frames, away from the LCA mounting points. This will give you plenty of room for working and moving the axle assemblies in and out. Leave the floor jack under the rear axle center section, holding the weight.
Remove the rear wheels.
Release the emergency brake.
Remove the screws holding the brake hose retaining brackets to the back side of the axle LCA brackets. Save the screws.
Remove the bolt that holds the brake line t-block to the top of the differential housing. Save the bolt, you "may" need it.
Bend up the clip on the top of each axle tube that holds the brake lines in place.
Remove the bolts in the differential cover that hold the emergency brake wire loop retainers in place. Put the bolts back in so you don’t lose them.
Remove the rear brake calipers. First compress the caliper with a c-clamp. Then remove the two bolts that hold the calipers to the caliper mounting bracket. These are conventional bolt heads. Do not remove the slider bolts in the caliper that you would remove if you were doing new brake pads. Do not separate the hydraulic hose. Hang the calipers up out of the way using a bent coat hanger. Check that the lines are up out of the way. If not, wire them up so they don’t get bent while you are working under the car.
Remove the rotors from the wheel studs.
Remove the sway bar. Start with the end links, then the u-bolts that hold the bushings to the axle tube. Put the nuts back on all the pieces so you don’t lose them.
Remove the lower shock mounting bolts and pull the bolts out of the holes in the brackets. If you are not replacing shocks, stop here and go to the next step. If you are replacing shocks, remove the top nuts too. They are under the carpet, where the flat part starts to bend down behind the seat. Fold the seatback down and pull the carpet out from under the side plastic wheel housing covers. There is a plastic foam "falsie" stuffed into the hole for the shock mount. Just pull it out and put it aside. Drop the shocks out and get them out of the way.
Remove the end of the panhard rod (track bar) from the axle housing bracket. Leave the body end attached. Wire the rod up to the body to keep it out of the way.
Be sure you have left the LCA’s and TA in place it this time. This keeps the axle from rotating and letting the springs fly out.
Lower the axle assembly with the floor jack. Check while you are lowering it to make sure you have not got the brake lines, or emergency brake cables, or anything else snagged on the axle. It will drop low enough for all the tension to go out of the springs. They will flop out and fall on the floor. Make sure to note how the upper spring rubber seats are located in the recesses in the body. I think it’s a good idea to put the seats and the springs back exactly the way they came out.
Remove the u-bolts that hold the u-joint to the pinion yoke.
You should be sure to have help for the next few steps:
Raise the axle back up ½ way. Support the nose of the pinion housing. Remove the TA bolts. These bolts can be really tight, because the torque spec is 97 ft-lb. Just be careful the axle doesn’t shift and fall off the jack.
Remove the LCA bolts from the axle brackets.
Make sure the axle assembly is balanced on the floor jack, remove whatever is holding the pinion up, lower the rear to the floor and roll the jack/axle out from under the car. Stare at the OEM axle and reflect on what a rusty old POS it is.
Remove your driveshaft. You may need to pry it out of the end of the tranny, if it is dried out and never been out before.
I was doing a lot of stuff at once, so this might affect the remove and replace procedures. I had the following to install, in addition to the Strange:
Baer "enhanced" rear brake package. Basically, a larger (11.7" x 0.80") drilled, slotted and zinc-washed rotor, using the OEM caliper. It also includes braided S/S hoses, but I did not do the hoses. One less complication, and I wanted to wait until I did the front brakes to change the fluid and bleed the system.
HAL 12-way adjustable shocks.
Eibach Pro-Kit springs.
Air Lift air bags.
I already had the following items installed, which connected to the OEM axle assembly:
Just Suspension box-section lower control arms.
Just Suspension adjustable panhard rod.
Spohn adjustable torque arm.
Energy Suspension polyurethane bushings on the LCA’s, panhard, and sway bar, plus sway bar end links.
Since all these had been added in the past nine months, the bolts were all relatively rust free, and easy to loosen.
In the future, I hope to replace the OEM steel driveshaft, but not until I have the HP to render the stock unit useless. I really want the carbon fiber driveshaft, but it is very expensive.
Loosen the rear wheel lug nuts.
Check the brake fluid level in the brake master cylinder. If it is full, remove some fluid, so when you compress the rear calipers to remove them, the reservoir will not overflow. Be careful – brake fluid is instant disaster on your paint.
Raise the rear section of the car. I pulled my car into my garage nose first, put my ramps under the rear wheels, and my 4-inch "booster" boards (stacked, staggered 2x10’s) under the front. Backed it up on the ramps. Before you do anything, put chocks under the front wheels, front and back. Eventually, you will have no driveshaft and no emergency brakes to hold the car.
Raise it another 6-inches or so with a floor jack under the axle and put jack stands under the sub-frames, away from the LCA mounting points. This will give you plenty of room for working and moving the axle assemblies in and out. Leave the floor jack under the rear axle center section, holding the weight.
Remove the rear wheels.
Release the emergency brake.
Remove the screws holding the brake hose retaining brackets to the back side of the axle LCA brackets. Save the screws.
Remove the bolt that holds the brake line t-block to the top of the differential housing. Save the bolt, you "may" need it.
Bend up the clip on the top of each axle tube that holds the brake lines in place.
Remove the bolts in the differential cover that hold the emergency brake wire loop retainers in place. Put the bolts back in so you don’t lose them.
Remove the rear brake calipers. First compress the caliper with a c-clamp. Then remove the two bolts that hold the calipers to the caliper mounting bracket. These are conventional bolt heads. Do not remove the slider bolts in the caliper that you would remove if you were doing new brake pads. Do not separate the hydraulic hose. Hang the calipers up out of the way using a bent coat hanger. Check that the lines are up out of the way. If not, wire them up so they don’t get bent while you are working under the car.
Remove the rotors from the wheel studs.
Remove the sway bar. Start with the end links, then the u-bolts that hold the bushings to the axle tube. Put the nuts back on all the pieces so you don’t lose them.
Remove the lower shock mounting bolts and pull the bolts out of the holes in the brackets. If you are not replacing shocks, stop here and go to the next step. If you are replacing shocks, remove the top nuts too. They are under the carpet, where the flat part starts to bend down behind the seat. Fold the seatback down and pull the carpet out from under the side plastic wheel housing covers. There is a plastic foam "falsie" stuffed into the hole for the shock mount. Just pull it out and put it aside. Drop the shocks out and get them out of the way.
Remove the end of the panhard rod (track bar) from the axle housing bracket. Leave the body end attached. Wire the rod up to the body to keep it out of the way.
Be sure you have left the LCA’s and TA in place it this time. This keeps the axle from rotating and letting the springs fly out.
Lower the axle assembly with the floor jack. Check while you are lowering it to make sure you have not got the brake lines, or emergency brake cables, or anything else snagged on the axle. It will drop low enough for all the tension to go out of the springs. They will flop out and fall on the floor. Make sure to note how the upper spring rubber seats are located in the recesses in the body. I think it’s a good idea to put the seats and the springs back exactly the way they came out.
Remove the u-bolts that hold the u-joint to the pinion yoke.
You should be sure to have help for the next few steps:
Raise the axle back up ½ way. Support the nose of the pinion housing. Remove the TA bolts. These bolts can be really tight, because the torque spec is 97 ft-lb. Just be careful the axle doesn’t shift and fall off the jack.
Remove the LCA bolts from the axle brackets.
Make sure the axle assembly is balanced on the floor jack, remove whatever is holding the pinion up, lower the rear to the floor and roll the jack/axle out from under the car. Stare at the OEM axle and reflect on what a rusty old POS it is.
Remove your driveshaft. You may need to pry it out of the end of the tranny, if it is dried out and never been out before.
Last edited by Viper; 12-15-2004 at 07:08 PM.
12-12-2004 | 10:33 AM
#4
Thread Starter
Joined: Dec 2001
Posts: 4,908
Likes: 3
From: Cleveland, OH
Intermission:
First, a word of caution. Call this "Lesson learned #1". When I received my Strange, I was surprised that there was a black cover plate over the ABS sensor opening, held in with an Allen screw. I was surprised because the Strange catalog says that the ABS sensor comes with the standard assembly. But, I figured "no big deal, I’ll just swap out my old one". WRONG!!! I tried to open the cover at one point, but it was in there pretty solid, so I figured no sense messing it up, I’ll just wait until it is time to swap the old sensor in. Well, I pull the stock ABS sensor out of the stock axle, and pop the metal cover/plug off the Strange. OOOOOPS!! They are not the same size and shape… Then I look into the hole in the Strange, and NO RELUCTOR RING!!!
At this point I need to decide… continue on, or let it sit and call Strange on Monday morning. Figured, the hell with it, she’s going in. I later discovered that Strange "forgot" to put the reluctor ring on the super-strength posi unit, and since there was no reluctor ring, nobody bothered to install a sensor. No problem – Strange agreed my order was clear, it was their error, and they would send me a new posi and pay the cost of my having it installed locally. Honorable, but a bit inconvenient. So, when your axle arrives, make sure it has a sensor, and inside the sensor opening there are the teeth of the reluctor wheel.
You need to take the driveshaft and the new U-joint to a shop and have the old one pressed out and the new one pressed in. I though I could pound the old one out, but it didn’t work. Unstable Bob tells me they use a nylon ring to hold it all together, and you need to melt the nylon ring out to get it apart. Let the shop do it right for $10.
Now is the time to clean and paint anything you want to spruce up a bit. I cleaned up and painted the parts of the sway bar including the brackets, and the driveshaft.
While you have the axles side by side, compare the location of the screw hole in the driver’s side LCA bracket, for mounting the brake hose retaining clip. On my factory unit, the hole was located toward the inside of the LCA bracket, allowing the brake hose clip to mount horizontally, with the tang on the bracket bent around the inside edge of the LCA bracket. On the Strange axle assembly, the screw hole it too far toward the "outside" (or toward the driver’s side). Now is the time to make sure the hole is in the right place. Drill a new one if needed.
Install the new axle assembly:
Put the driveshaft into the transmission, protecting the ends of the U-joint.
Put the new axle assembly on the floor jack and roll it into place. Raise it up and connect the LCA’s (bolt - 80 ft-lb; or nut – 60 ft-lb.). While you are doing this, be careful. The new axle weighs 162#, and will rotate in either direction when held only by the LCA’s. If it spins while you are under it, it will hurt at best, and kill you at the worst!
Raise it up and put a bottle jack under the pinion. Raise the bottle jack until the pinion is level with the TA, and slide the TA sideways over the pinion housing. If you have an aftermarket TA, like my Spohn Race version, you will need to grind away the upper right rear corner on the top quite a ways, and a little off the lower right rear corner. The bolts will not go through the top of the TA, into the diff housing, and out the bottom bracket unless the fit is perfect. (97 ft-lb)
Install the U-bolts that hold the U-joint to the pinion yoke (16 ft-lb).
If you have changed your shocks, put the new ones in now. If you kept the old shocks, the top is still in place. Extend the shocks to their full length. Upper shock bolts – 13 ft-lb.
Reattach the end of the panhard rod to the axle (bolt - 75 ft-lb).
Put the springs on the axle lower seats, and the upper rubber spring seats on the tops of the springs (if the seats fell out of the body. One of mine did and one didn’t.). Make sure the end/pigtail of the spring is properly in the recess in the rubber upper seat.
Jack the axle up with the springs pointed into the wells in the body. Keep going up until the lower shock bolts are level with the holes in the axle brackets. Put the shock bolts into the axle brackets and put the nut on (lower shock bolts – 66 ft-lb).
Put the rotors on the wheel studs, and remount the brake calipers, using the old bolts (. Dress the brake and emergency brake lines correctly, but don’t fasten them yet.
Attach the brake hose retaining clips to the axle LCA brackets.
Put the emergency brake retainer wire loops under the appropriate rear diff cover bolts.
Pull the brake lines under the mid-axle clips and bend the clips loosely.
You will see that the t-block for the brakes will not reach the bolt hole in the top of the diff housing. You could reshape the brake lines to allow it to reach, or put an extension bracket under the t-block. I bought a new 5/16" x 18tpi bolt. The one I got was too long so I cut it off and re-threaded it. I put a 1-inch thick steel spacer (actually, two of the spacers that are used on the bolts/studs that hold the factory exhaust manifolds on – never discard anything!!) between the t-block and the differential housing. This requires a 2-1/2" bolt.
Install the sway bar. At this point, there is a potential problem. The sway bar is too close to the aluminum rear diff cover. The fix here is to rotate the u-bolts/brackets that hold the sway bar bushings so the bushings move back and slightly upwards around the tubes. This will give you a little extra clearance here. The sway bar end links will accommodate this movement. The u-bolt brackets have a small notch cut in the center, and this notch matches a metal tab welded to the axle tube. Hence, unless you open up the notch, there is only one way the u-bolt/bracket can go on the axle, and that is with the brackets at the bottom of the axle tube, in the 6-o’clock position. I wanted to rotate the bracket toward the rear, so I enlarged the notch to twice it’s original size, cutting the added width all on one side of the notch. This only gives you about 20o rotation, but I believe this will be enough. Comments to follow on this experience. Tighten the U-bolt nuts to 20 ft-lb, and the end link bolts to 18 ft-lb.
Install the rear wheels, tightening the lug nuts as much as possible without pushing the car off the jack stands. Use a torque wrench, to 100 ft-lb, in 20 ft-lb increments, in a star pattern.
Put the ramps under the rear wheels, raise the car and remove the jack stands, start the car and pump the brakes to make sure they work. Pull off the ramps.
Make sure the brake fluid is full.
Control your urge to drive your car up and down the street, testing for 5,000rpm launches. Clean up your work area, clean off all your tools, put your tools…… awww, screw it, try a few 5,000rpm launches….be happy.
First, a word of caution. Call this "Lesson learned #1". When I received my Strange, I was surprised that there was a black cover plate over the ABS sensor opening, held in with an Allen screw. I was surprised because the Strange catalog says that the ABS sensor comes with the standard assembly. But, I figured "no big deal, I’ll just swap out my old one". WRONG!!! I tried to open the cover at one point, but it was in there pretty solid, so I figured no sense messing it up, I’ll just wait until it is time to swap the old sensor in. Well, I pull the stock ABS sensor out of the stock axle, and pop the metal cover/plug off the Strange. OOOOOPS!! They are not the same size and shape… Then I look into the hole in the Strange, and NO RELUCTOR RING!!!
At this point I need to decide… continue on, or let it sit and call Strange on Monday morning. Figured, the hell with it, she’s going in. I later discovered that Strange "forgot" to put the reluctor ring on the super-strength posi unit, and since there was no reluctor ring, nobody bothered to install a sensor. No problem – Strange agreed my order was clear, it was their error, and they would send me a new posi and pay the cost of my having it installed locally. Honorable, but a bit inconvenient. So, when your axle arrives, make sure it has a sensor, and inside the sensor opening there are the teeth of the reluctor wheel.
You need to take the driveshaft and the new U-joint to a shop and have the old one pressed out and the new one pressed in. I though I could pound the old one out, but it didn’t work. Unstable Bob tells me they use a nylon ring to hold it all together, and you need to melt the nylon ring out to get it apart. Let the shop do it right for $10.
Now is the time to clean and paint anything you want to spruce up a bit. I cleaned up and painted the parts of the sway bar including the brackets, and the driveshaft.
While you have the axles side by side, compare the location of the screw hole in the driver’s side LCA bracket, for mounting the brake hose retaining clip. On my factory unit, the hole was located toward the inside of the LCA bracket, allowing the brake hose clip to mount horizontally, with the tang on the bracket bent around the inside edge of the LCA bracket. On the Strange axle assembly, the screw hole it too far toward the "outside" (or toward the driver’s side). Now is the time to make sure the hole is in the right place. Drill a new one if needed.
Install the new axle assembly:
Put the driveshaft into the transmission, protecting the ends of the U-joint.
Put the new axle assembly on the floor jack and roll it into place. Raise it up and connect the LCA’s (bolt - 80 ft-lb; or nut – 60 ft-lb.). While you are doing this, be careful. The new axle weighs 162#, and will rotate in either direction when held only by the LCA’s. If it spins while you are under it, it will hurt at best, and kill you at the worst!
Raise it up and put a bottle jack under the pinion. Raise the bottle jack until the pinion is level with the TA, and slide the TA sideways over the pinion housing. If you have an aftermarket TA, like my Spohn Race version, you will need to grind away the upper right rear corner on the top quite a ways, and a little off the lower right rear corner. The bolts will not go through the top of the TA, into the diff housing, and out the bottom bracket unless the fit is perfect. (97 ft-lb)
Install the U-bolts that hold the U-joint to the pinion yoke (16 ft-lb).
If you have changed your shocks, put the new ones in now. If you kept the old shocks, the top is still in place. Extend the shocks to their full length. Upper shock bolts – 13 ft-lb.
Reattach the end of the panhard rod to the axle (bolt - 75 ft-lb).
Put the springs on the axle lower seats, and the upper rubber spring seats on the tops of the springs (if the seats fell out of the body. One of mine did and one didn’t.). Make sure the end/pigtail of the spring is properly in the recess in the rubber upper seat.
Jack the axle up with the springs pointed into the wells in the body. Keep going up until the lower shock bolts are level with the holes in the axle brackets. Put the shock bolts into the axle brackets and put the nut on (lower shock bolts – 66 ft-lb).
Put the rotors on the wheel studs, and remount the brake calipers, using the old bolts (. Dress the brake and emergency brake lines correctly, but don’t fasten them yet.
Attach the brake hose retaining clips to the axle LCA brackets.
Put the emergency brake retainer wire loops under the appropriate rear diff cover bolts.
Pull the brake lines under the mid-axle clips and bend the clips loosely.
You will see that the t-block for the brakes will not reach the bolt hole in the top of the diff housing. You could reshape the brake lines to allow it to reach, or put an extension bracket under the t-block. I bought a new 5/16" x 18tpi bolt. The one I got was too long so I cut it off and re-threaded it. I put a 1-inch thick steel spacer (actually, two of the spacers that are used on the bolts/studs that hold the factory exhaust manifolds on – never discard anything!!) between the t-block and the differential housing. This requires a 2-1/2" bolt.
Install the sway bar. At this point, there is a potential problem. The sway bar is too close to the aluminum rear diff cover. The fix here is to rotate the u-bolts/brackets that hold the sway bar bushings so the bushings move back and slightly upwards around the tubes. This will give you a little extra clearance here. The sway bar end links will accommodate this movement. The u-bolt brackets have a small notch cut in the center, and this notch matches a metal tab welded to the axle tube. Hence, unless you open up the notch, there is only one way the u-bolt/bracket can go on the axle, and that is with the brackets at the bottom of the axle tube, in the 6-o’clock position. I wanted to rotate the bracket toward the rear, so I enlarged the notch to twice it’s original size, cutting the added width all on one side of the notch. This only gives you about 20o rotation, but I believe this will be enough. Comments to follow on this experience. Tighten the U-bolt nuts to 20 ft-lb, and the end link bolts to 18 ft-lb.
Install the rear wheels, tightening the lug nuts as much as possible without pushing the car off the jack stands. Use a torque wrench, to 100 ft-lb, in 20 ft-lb increments, in a star pattern.
Put the ramps under the rear wheels, raise the car and remove the jack stands, start the car and pump the brakes to make sure they work. Pull off the ramps.
Make sure the brake fluid is full.
Control your urge to drive your car up and down the street, testing for 5,000rpm launches. Clean up your work area, clean off all your tools, put your tools…… awww, screw it, try a few 5,000rpm launches….be happy.
Last edited by Viper; 12-15-2004 at 07:08 PM.
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12-15-2004 | 07:27 PM
#12
TECH Enthusiast
Joined: Jul 2003
Posts: 580
Likes: 0
From: The Republic of Texas
Originally Posted by Viper
[b] Stare at the OEM axle and reflect on what a rusty old POS it is......
Thank you for the play by play on this install, great detail and information, I'll be sure to print this out when I do mine. Again thanks for taking the time to write this!
never noticed that before 
