4L60E 2-4 shift trouble
07-18-2013, 02:29 PM
#1
4L60E 2-4 shift trouble Hi All, I'm not trying to hijack this thread but the title of "4l60E Problem" seems a good place to start.
I know this is a forum for LS1's but from what I have seen, you guys know the 4L60E inside and out. I have a 2003 Avalanche with 200k miles and a stock engine and trans. A few years ago, it would randomly go into limp mode and would only take off in 3rd. I changed fluid and filter and pulled and checked solenoids and they were fine. Put it back together and truck drove fine for a while. It later did it again off and on for about 6 months and the MIL came on. I took it to a GM dealer but it wouldn’t act up for them. They scanned it and I got P0740, 1870 and 0758 codes. They cleared the codes and told me that these codes were common when the ignition switch was going out but they couldn’t be sure unless it was acting up during their inspection. They said to drive it and bring it back if it did it again. I drove it and didn’t have the problem after that. The MIL came on again a few weeks later but the truck drove fine so I just let it stay on.
A few months ago, I started to notice a very slight "miss" at the very top of 2nd gear, right before it would shift into 3rd. It didn’t feel like a slip and it was barely even noticeable. I checked the fluid level, color, smell, and all were good. I continued to drive it, taking it easy, as time and money were tight.
The 2-3 "miss" didn’t seem to change or get worse, but a couple weeks ago, I got in my truck to go somewhere and it wouldn’t shift out of first gear. I tried it manually and it would not go into 2nd, it just stayed in first. Same when I manually put it in 3rd and D. After some test driving, I found that if I put it in D, then got the rpms up to about 2-3k in 1st gear, and let all the way off the gas, that it would simply skip over second and go straight to 3rd and then on to 4th as normal. I never once felt or heard a slip in 1, 3, D, or R, there were no slips, no leaks, no smell, no shudder, no noise, no flare. It just would not shift into 2nd gear. Again, money and time were tight, so I drove it like that for a few days but only on short trips (5-10 miles). The other day, I had to go on a 100 mile drive. As usual, I put in D, it took off in 1st as normal, I let off the gas at about 2-3k rpms and it shifted smoothly into 3rd gear, once up to speed, it went into 4th and all was good. After about an hour of going 75mph, I got a message on the dash saying the trans was hot. So, I pulled over and let it sit for a while. I checked the fluid, it still looked ok. After it cooled off, I decided to try and limp it home. I put it in D, it took off in 1st, skipped second and went to 3rd, but then it stayed in 3rd. I had now lost the shift to 4th. One other thing I found was that if I hit the button for Tow Mode, I could not get the trans to shift out of first no matter how high I revved the engine and let off the gas. As soon as I turned the Tow Mode off, it would go back to shifting from 1st to 3rd once I let off the gas.
So, I drove home in 3rd at about 40mph and made it with no more warnings.
I have rebuilt a couple older engines and have always been pretty good mechanically but have never worked on an auto trans. I started researching online to help educate myself on the subject and did the following:
Borrowed a buddy’s scan tool and scanned truck and had a P0101 code for MAF Sensor. I cleaned it, drove it around on a couple very short trips and the MIL light finally went out. No other codes came up at all.
Checked voltage at IGN 0 fuse, trans connector and white wire off ign switch, all good.
Checked all ground feeds from PCM to Trans to make sure none were shorted together or to ground and they were all good. I was hoping to find the problem here as I read that the shift solenoids are set up so that when both are on in 1st and both are off in 3rd, while the 2nd and 4th states oppose each other. I was hoping maybe the solenoid grounds were touching and causing me to have only 1st and 3rd but I did not find that to be the case.
I dropped the pan and valve body. I checked all the valves and check ***** and they all move freely and nothing seemed to be stuck. Checked solenoids and they were all within specified ohms. I also tested them with a 12v power supply and they actuate.
I did find a broken 3-2 control valve spring and I found that the check ***** had deformed the separator plate holes.
The accumulators seem to be ok. They are not loose or cracked and move smoothly in their bore.
I can see the 2-4 band through the case near the front of the valve body and it appears to be intact and the anchored end is still anchored. I put air into the 2nd apply to the servo and can I see the band engage firmly on the drum. I did the same with the 4th apply circuit and the band tightens up firmly as well. However, I did notice that when I was air checking the servo, that air continued to flow out of the opposite circuit. I assumed that meant my servo seals were shot so I pulled the servo out. The seals look a little worn but they were intact and not torn or anything. Either way, I don't think air should be able to pass between the 2nd and 4th apply circuits, but I may be wrong.
I also found some photos online of the ends of the band through the inspection hole and noticed that my band seems to have less gap between the ends than the photos I have seen. During the air check of the servo, when the band is applied, the gap is about 3/8" or so between the ends of the band, but the photos I saw look like there was about twice that. I am assuming that my band and drum are worn and are thinner than new ones are, which would explain the smaller gap. I'm really hoping I can get a bit more life out of it before having to rebuild.
So, that brings me to here. As I said, money is really tight and I need to get my truck back up and going asap. I know that with 200k miles, that I should just be rebuilding the whole trans. The thing is, beyond being low on cash, that the trans works perfectly other than the 2 and 4 shifts. I would think that if the gears, band, bearings, clutches, TC and pump were shot, that all the gears would have issues and it would be slipping, clunking, grinding, vibrating, etc... But I have none of that. I am hoping I can get by with some simple mods and a few new parts but have been trying to decide what might fix this for a while longer without breaking the bank and wanted to see what you guys on here thought. I have read a LOT of forums trying to learn and you LS1Tech members seem to know more about this trans than the people on any other site.
I was thinking of getting the following:
A Transgo HD2 shift kit as this should give me all new VB seals and replace the broken 3-2 spring, along with the bigger boost valve and P1870 fix.
A Transgo separator plate to fix the issue with the worn check ball seats. Unless the Fitzall check ball/plate repair kit would work.
Pinless accumulators, even though mine appear ok, I have no idea how to be sure and these are cheap insurance while I have the VB out.
A corvette Servo with new seals to get more pressure on the band.
Then I was thinking of welding up the end of the servo pin to make it about an 1/8" longer so it would be able to engage the band better. That is, unless I can find a good deal on the Vette servo that includes a longer pin. I hate being poor!
Anyway, I'm sorry for the long post but I wanted to make sure I gave the facts as best I could so you guys with the experience may be able to get me on the right path.
I'd greatly appreciate any info or advice you can provide, even if it's just to tell me I'm an idiot and that I'm screwed and to take my 4x4 and stop bugging you Camaro guys.
Thanks!
I know this is a forum for LS1's but from what I have seen, you guys know the 4L60E inside and out. I have a 2003 Avalanche with 200k miles and a stock engine and trans. A few years ago, it would randomly go into limp mode and would only take off in 3rd. I changed fluid and filter and pulled and checked solenoids and they were fine. Put it back together and truck drove fine for a while. It later did it again off and on for about 6 months and the MIL came on. I took it to a GM dealer but it wouldn’t act up for them. They scanned it and I got P0740, 1870 and 0758 codes. They cleared the codes and told me that these codes were common when the ignition switch was going out but they couldn’t be sure unless it was acting up during their inspection. They said to drive it and bring it back if it did it again. I drove it and didn’t have the problem after that. The MIL came on again a few weeks later but the truck drove fine so I just let it stay on.
A few months ago, I started to notice a very slight "miss" at the very top of 2nd gear, right before it would shift into 3rd. It didn’t feel like a slip and it was barely even noticeable. I checked the fluid level, color, smell, and all were good. I continued to drive it, taking it easy, as time and money were tight.
The 2-3 "miss" didn’t seem to change or get worse, but a couple weeks ago, I got in my truck to go somewhere and it wouldn’t shift out of first gear. I tried it manually and it would not go into 2nd, it just stayed in first. Same when I manually put it in 3rd and D. After some test driving, I found that if I put it in D, then got the rpms up to about 2-3k in 1st gear, and let all the way off the gas, that it would simply skip over second and go straight to 3rd and then on to 4th as normal. I never once felt or heard a slip in 1, 3, D, or R, there were no slips, no leaks, no smell, no shudder, no noise, no flare. It just would not shift into 2nd gear. Again, money and time were tight, so I drove it like that for a few days but only on short trips (5-10 miles). The other day, I had to go on a 100 mile drive. As usual, I put in D, it took off in 1st as normal, I let off the gas at about 2-3k rpms and it shifted smoothly into 3rd gear, once up to speed, it went into 4th and all was good. After about an hour of going 75mph, I got a message on the dash saying the trans was hot. So, I pulled over and let it sit for a while. I checked the fluid, it still looked ok. After it cooled off, I decided to try and limp it home. I put it in D, it took off in 1st, skipped second and went to 3rd, but then it stayed in 3rd. I had now lost the shift to 4th. One other thing I found was that if I hit the button for Tow Mode, I could not get the trans to shift out of first no matter how high I revved the engine and let off the gas. As soon as I turned the Tow Mode off, it would go back to shifting from 1st to 3rd once I let off the gas.
So, I drove home in 3rd at about 40mph and made it with no more warnings.
I have rebuilt a couple older engines and have always been pretty good mechanically but have never worked on an auto trans. I started researching online to help educate myself on the subject and did the following:
Borrowed a buddy’s scan tool and scanned truck and had a P0101 code for MAF Sensor. I cleaned it, drove it around on a couple very short trips and the MIL light finally went out. No other codes came up at all.
Checked voltage at IGN 0 fuse, trans connector and white wire off ign switch, all good.
Checked all ground feeds from PCM to Trans to make sure none were shorted together or to ground and they were all good. I was hoping to find the problem here as I read that the shift solenoids are set up so that when both are on in 1st and both are off in 3rd, while the 2nd and 4th states oppose each other. I was hoping maybe the solenoid grounds were touching and causing me to have only 1st and 3rd but I did not find that to be the case.
I dropped the pan and valve body. I checked all the valves and check ***** and they all move freely and nothing seemed to be stuck. Checked solenoids and they were all within specified ohms. I also tested them with a 12v power supply and they actuate.
I did find a broken 3-2 control valve spring and I found that the check ***** had deformed the separator plate holes.
The accumulators seem to be ok. They are not loose or cracked and move smoothly in their bore.
I can see the 2-4 band through the case near the front of the valve body and it appears to be intact and the anchored end is still anchored. I put air into the 2nd apply to the servo and can I see the band engage firmly on the drum. I did the same with the 4th apply circuit and the band tightens up firmly as well. However, I did notice that when I was air checking the servo, that air continued to flow out of the opposite circuit. I assumed that meant my servo seals were shot so I pulled the servo out. The seals look a little worn but they were intact and not torn or anything. Either way, I don't think air should be able to pass between the 2nd and 4th apply circuits, but I may be wrong.
I also found some photos online of the ends of the band through the inspection hole and noticed that my band seems to have less gap between the ends than the photos I have seen. During the air check of the servo, when the band is applied, the gap is about 3/8" or so between the ends of the band, but the photos I saw look like there was about twice that. I am assuming that my band and drum are worn and are thinner than new ones are, which would explain the smaller gap. I'm really hoping I can get a bit more life out of it before having to rebuild.
So, that brings me to here. As I said, money is really tight and I need to get my truck back up and going asap. I know that with 200k miles, that I should just be rebuilding the whole trans. The thing is, beyond being low on cash, that the trans works perfectly other than the 2 and 4 shifts. I would think that if the gears, band, bearings, clutches, TC and pump were shot, that all the gears would have issues and it would be slipping, clunking, grinding, vibrating, etc... But I have none of that. I am hoping I can get by with some simple mods and a few new parts but have been trying to decide what might fix this for a while longer without breaking the bank and wanted to see what you guys on here thought. I have read a LOT of forums trying to learn and you LS1Tech members seem to know more about this trans than the people on any other site.
I was thinking of getting the following:
A Transgo HD2 shift kit as this should give me all new VB seals and replace the broken 3-2 spring, along with the bigger boost valve and P1870 fix.
A Transgo separator plate to fix the issue with the worn check ball seats. Unless the Fitzall check ball/plate repair kit would work.
Pinless accumulators, even though mine appear ok, I have no idea how to be sure and these are cheap insurance while I have the VB out.
A corvette Servo with new seals to get more pressure on the band.
Then I was thinking of welding up the end of the servo pin to make it about an 1/8" longer so it would be able to engage the band better. That is, unless I can find a good deal on the Vette servo that includes a longer pin. I hate being poor!
Anyway, I'm sorry for the long post but I wanted to make sure I gave the facts as best I could so you guys with the experience may be able to get me on the right path.
I'd greatly appreciate any info or advice you can provide, even if it's just to tell me I'm an idiot and that I'm screwed and to take my 4x4 and stop bugging you Camaro guys.
Thanks!
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Yasin usta (12-24-2023)
07-18-2013, 02:56 PM
#2
Moderator
First, it is obvious that you know a lot about how to diagnose trans problems and have already checked a lot of things.
Since it sounds like your problem is only 2nd and 4th gears, it is almost certainly a band and/or servo problem.
I would first check the end play of the servo by pressing in on the servo cover with a tool, e.g. crowbar, and estimating how far it moves. The suggested end play is .075 to .125, i.e. 1/16 to 1/8". If it is more than about 3/16" then your band is likely worn. At that point you could weld on a 1/8" "blob" at the end of the servo pin (and round it off smooth) to get your endplay into spec. Adding a Corvette servo is a good idea too. This will be a bit of a bandaid and might not even work, but it may give your 2nd and 4th gear back for a while.
These Sonnax instructions might help you get the servo pin to the correct length and shape:
http://www.sonnax.com/system/instruc...911-03K-IN.pdf
You could buy this ($80) to get a good servo and longer pin, but seems like an overkill in your case, since you know how to weld. A Corvette servo is only about $15.
The HD2 kit might be useful, but is again a bit of an overkill. VB gaskets are only a few dollars. I would be happy to send you a stock 3-2 downshift spring. The Sonnax 4L60E-LB1 is a better boost valve as it has o-ring seals. (in another thread this week, the OP concluded that changing from the HD2 boost valve to the Sonnax cured a bunch of problems.)
However getting a new Transgo separator plate is an excellent idea! You will need .082 and .093 drills to drill it properly. (And maybe .101 too) Might as well add the Sonnax Torlon check ***** then too; part #10000-08.
Pinless pistons are nice. Just know that the HD2 kit's springs for the 1-2 accumulator do NOT work with a pinless piston.
I hope that gives you some guidance. No guarantees, but it is worth a shot.
Since it sounds like your problem is only 2nd and 4th gears, it is almost certainly a band and/or servo problem.
I would first check the end play of the servo by pressing in on the servo cover with a tool, e.g. crowbar, and estimating how far it moves. The suggested end play is .075 to .125, i.e. 1/16 to 1/8". If it is more than about 3/16" then your band is likely worn. At that point you could weld on a 1/8" "blob" at the end of the servo pin (and round it off smooth) to get your endplay into spec. Adding a Corvette servo is a good idea too. This will be a bit of a bandaid and might not even work, but it may give your 2nd and 4th gear back for a while.
These Sonnax instructions might help you get the servo pin to the correct length and shape:
http://www.sonnax.com/system/instruc...911-03K-IN.pdf
You could buy this ($80) to get a good servo and longer pin, but seems like an overkill in your case, since you know how to weld. A Corvette servo is only about $15.
The HD2 kit might be useful, but is again a bit of an overkill. VB gaskets are only a few dollars. I would be happy to send you a stock 3-2 downshift spring. The Sonnax 4L60E-LB1 is a better boost valve as it has o-ring seals. (in another thread this week, the OP concluded that changing from the HD2 boost valve to the Sonnax cured a bunch of problems.)
However getting a new Transgo separator plate is an excellent idea! You will need .082 and .093 drills to drill it properly. (And maybe .101 too) Might as well add the Sonnax Torlon check ***** then too; part #10000-08.
Pinless pistons are nice. Just know that the HD2 kit's springs for the 1-2 accumulator do NOT work with a pinless piston.
I hope that gives you some guidance. No guarantees, but it is worth a shot.
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Yasin usta (12-24-2023)
07-21-2013, 09:45 AM
#3
Hey Mrvedit,
Thanks for the reply! Sorry I didn't get back sooner. I thought I'd get an email notification if anyone replied to my post but now I see I forgot to subscribe to it.
Anyway, I really appreciate the advice and the offer on the spring. It seems like I cant find all these parts at one place so I have been shopping around for the best deal. I called Summit Racing to pick their brain a bit and had every intention of ordering everything from them but I knew more about my trans than the guy I talked to... Go figure. I guess I'll call someone else.
So, if the HD-2 kit is overkill, is there another, more basic kit you'd recommend that may help me out? I'm not looking to gain any performance but I do pull trailers sometimes. I was happy with the stock setup but I also wouldn't care if I had firmer shifts. I'm not picky on that part. I just need a drivable truck again.
As for the servo cover travel, I reinstalled my servo and was able to push it in about a 3/8" to 1/2" before it bottomed out. I'm sure my band/drum is on its last leg but if I could get another 10-20k miles out of it, I'd be one happy camper!
On the servo pin, I have no problem welding and grinding it but I was just afraid to buy a servo without a pin in case my stock one was worn or wouldn't fit in the new servo. Are all the servos and pins (aftermarket or stock) interchangeable?
I have seen you write about Dana at Pro Built and that he may be able to put together a custom package if you call him. I looked at his site and found the servo I was thinking of getting: https://www.700r4l60e.com/store/prod...7&cat=0&page=3
Even though parts like the 3-2 spring and pressure manifold switch are not shown on his site, I imagine he probably has them. I just hate to call and bug him with my measly order when I'm sure he'd rather spend his time selling custom $2500 race units. What do you think?
I did find this on Danas site too: https://www.700r4l60e.com/store/prod...0&cat=0&page=2
It looks like it may have everything I need, including the servo, pinless accumulators and an option to get a pre-drilled plate. It comes with a boost valve but I assume it's a Transgo and you had mentioned the Sonnax boost valve may be better for me than the one that comes with the Transgo kit. I wonder if Dana would be able to modify the kit further and swap valves?
Ok, last question. I forgot to mention this and could not seem to find much detail anywhere. The pressure manifold switch. It has 5 pins on the connector, 2 of which are for the temp sensor (pins A and B), That leaves 3 pins, one of them is ground (pin E). The manifold has R, L, D2, D3, D4 pressure sensors on it. I tested for continuity between the ground and the other 2 pins and found that when I pushed on L or R, that I get continuity on pin C. When pushing D4, I get cont on pin D. That left the sensors for D2 and D3. I found that while testing the D4 sensor, that pushing D3 at the same time would break cont between D4 and pin D. While testing L or R on pin C, I found that pushing either D2 or D3 would break the connection from either L or R to pin C. Is this the proper operation of the manifold switch?
I hate to keep saying it but, thanks soooo much for your help!
Thanks for the reply! Sorry I didn't get back sooner. I thought I'd get an email notification if anyone replied to my post but now I see I forgot to subscribe to it.
Anyway, I really appreciate the advice and the offer on the spring. It seems like I cant find all these parts at one place so I have been shopping around for the best deal. I called Summit Racing to pick their brain a bit and had every intention of ordering everything from them but I knew more about my trans than the guy I talked to... Go figure. I guess I'll call someone else.
So, if the HD-2 kit is overkill, is there another, more basic kit you'd recommend that may help me out? I'm not looking to gain any performance but I do pull trailers sometimes. I was happy with the stock setup but I also wouldn't care if I had firmer shifts. I'm not picky on that part. I just need a drivable truck again.
As for the servo cover travel, I reinstalled my servo and was able to push it in about a 3/8" to 1/2" before it bottomed out. I'm sure my band/drum is on its last leg but if I could get another 10-20k miles out of it, I'd be one happy camper!
On the servo pin, I have no problem welding and grinding it but I was just afraid to buy a servo without a pin in case my stock one was worn or wouldn't fit in the new servo. Are all the servos and pins (aftermarket or stock) interchangeable?
I have seen you write about Dana at Pro Built and that he may be able to put together a custom package if you call him. I looked at his site and found the servo I was thinking of getting: https://www.700r4l60e.com/store/prod...7&cat=0&page=3
Even though parts like the 3-2 spring and pressure manifold switch are not shown on his site, I imagine he probably has them. I just hate to call and bug him with my measly order when I'm sure he'd rather spend his time selling custom $2500 race units. What do you think?
I did find this on Danas site too: https://www.700r4l60e.com/store/prod...0&cat=0&page=2
It looks like it may have everything I need, including the servo, pinless accumulators and an option to get a pre-drilled plate. It comes with a boost valve but I assume it's a Transgo and you had mentioned the Sonnax boost valve may be better for me than the one that comes with the Transgo kit. I wonder if Dana would be able to modify the kit further and swap valves?
Ok, last question. I forgot to mention this and could not seem to find much detail anywhere. The pressure manifold switch. It has 5 pins on the connector, 2 of which are for the temp sensor (pins A and B), That leaves 3 pins, one of them is ground (pin E). The manifold has R, L, D2, D3, D4 pressure sensors on it. I tested for continuity between the ground and the other 2 pins and found that when I pushed on L or R, that I get continuity on pin C. When pushing D4, I get cont on pin D. That left the sensors for D2 and D3. I found that while testing the D4 sensor, that pushing D3 at the same time would break cont between D4 and pin D. While testing L or R on pin C, I found that pushing either D2 or D3 would break the connection from either L or R to pin C. Is this the proper operation of the manifold switch?
I hate to keep saying it but, thanks soooo much for your help!
07-21-2013, 08:23 PM
#4
Moderator
If you are towing trailers, you should consider the Sonnax 4th gear servo.:
http://www.sonnax.com/system/instructions/77767K-IN.pdf
Otherwise the band can slip in 4th gear when towing up hill; might be why your band is so worn.
Or the Superior 4th gear servo:
http://hptransparts.com/superior-super-servo-4th.html
Sonnax also make a 2nd gear servo, if you decide on that, get the matching Sonnax 4th gear servo. The Corvette servo should be enough for your 2nd gear though.
With 3/8-1/2" end play, your band might be toast and you need a rebuild. Of course any servos you buy can be then be used on your rebuilt trans.
The Corvette servo Dana (member PBA) sells with the better seals is a good product. Perhaps a few dollar more than elsewhere, but Dana is known for good service. However the modified Transgo shift kit looks like an excellent deal as it includes some nice Sonnax parts too. Get the pre-drilled separator plate too (!) they do wear out. You would still need a 4th gear servo; I would ask Dana which one (Sonnax or Superior) would work better with his kit. I'm sure he has the VB spring you need too, or PM me your address and I will send you one this week.
I didn't quite understand your Q about the pressure manifold, but the following electrical diagram of the trans should answer it for you:
http://www.msgpio.com/manuals/mshift/wiring.html
In short, your band probably is fried, but all the parts I have mentioned will be good additions if/when you get it rebuilt. (Also be sure who ever rebuilds it uses a 4L65E rebuilt kit as it has a better 3/4 clutch and that kit will fit any 4L60E, at least '95 and later.)
http://www.sonnax.com/system/instructions/77767K-IN.pdf
Otherwise the band can slip in 4th gear when towing up hill; might be why your band is so worn.
Or the Superior 4th gear servo:
http://hptransparts.com/superior-super-servo-4th.html
Sonnax also make a 2nd gear servo, if you decide on that, get the matching Sonnax 4th gear servo. The Corvette servo should be enough for your 2nd gear though.
With 3/8-1/2" end play, your band might be toast and you need a rebuild. Of course any servos you buy can be then be used on your rebuilt trans.
The Corvette servo Dana (member PBA) sells with the better seals is a good product. Perhaps a few dollar more than elsewhere, but Dana is known for good service. However the modified Transgo shift kit looks like an excellent deal as it includes some nice Sonnax parts too. Get the pre-drilled separator plate too (!) they do wear out. You would still need a 4th gear servo; I would ask Dana which one (Sonnax or Superior) would work better with his kit. I'm sure he has the VB spring you need too, or PM me your address and I will send you one this week.
I didn't quite understand your Q about the pressure manifold, but the following electrical diagram of the trans should answer it for you:
http://www.msgpio.com/manuals/mshift/wiring.html
In short, your band probably is fried, but all the parts I have mentioned will be good additions if/when you get it rebuilt. (Also be sure who ever rebuilds it uses a 4L65E rebuilt kit as it has a better 3/4 clutch and that kit will fit any 4L60E, at least '95 and later.)
07-25-2013, 04:00 PM
#7
I got my parts today and had a question on the Transgo separator plate. You had mentioned I should drill it. I assumed the plate I structures would tell me what to drill but it says to only drill it if I'm installing a shift Kit or programming kit. I didn't get a shift Kit. I just got the vette Servo, a sonnax boost valve, pinless forward accumulator and all new seals and o-rings.
With this setup, do I still to drill the plate? If so, can you tell me what holes to enlarge?
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07-25-2013, 08:41 PM
#8
Moderator
Hmmm, when I buy them they always have instructions.
I took a pic of the instructions in post #11 of this thread:
https://ls1tech.com/forums/automatic...ift-flare.html
I would suggest .082 for the 2nd feed hole.
I would suggest .093 for the 3rd feed hole.
Or just drill them all bigger. Just kidding!!!
I assume you got new separator plate gaskets too.
You will need vaseline to hold the check ***** in place when you assemble everything. Remember the one checkball in the case by the 3-4 accumulator. Definitely need vaseline for that one.
Be VERY careful to get the VB bolts in the correct position. If you incorrectly install a long one in the middle, it will jam the internals. See Page 5 of the Transgo HD2 shift kit instructions for details:
https://ls1tech.com/forums/automatic...questions.html
Email me if you need quick help or my phone number: ted -at- vedit -dot- com.
I took a pic of the instructions in post #11 of this thread:
https://ls1tech.com/forums/automatic...ift-flare.html
I would suggest .082 for the 2nd feed hole.
I would suggest .093 for the 3rd feed hole.
Or just drill them all bigger. Just kidding!!!
I assume you got new separator plate gaskets too.
You will need vaseline to hold the check ***** in place when you assemble everything. Remember the one checkball in the case by the 3-4 accumulator. Definitely need vaseline for that one.
Be VERY careful to get the VB bolts in the correct position. If you incorrectly install a long one in the middle, it will jam the internals. See Page 5 of the Transgo HD2 shift kit instructions for details:
https://ls1tech.com/forums/automatic...questions.html
Email me if you need quick help or my phone number: ted -at- vedit -dot- com.
07-27-2013, 05:33 PM
#9
GOOD NEWS!!!!
I did the mods mentioned above and my truck drives like new! I have 2nd and 4th back and they are strong. I have no idea which of the new parts or which mod fixed my problem, but I'm damn glad it's fixed. At WOT, my 1-2 and 2-3 shifts are nice and firm and at low speeds they are nice and smooth.
I had bought a Fitzall Servo pin extender but I broke it in half while trying to hammer it onto my pin, so I ended up welding about a 1/4" blob on the pin. I ground and shaped it to make it about 3/16" longer overall. Luckily, that seems to have been the perfect length.
I also ground a bevel onto the manual shift valve to make it easier to move the shifter when on a hill but haven't had a chance to try that yet.
The only negative thing I have noticed is that when I am in second and mash the pedal, the downshift into first is a pretty harsh but other than that, I think its perfect! For never working on a trans before, I feel pretty lucky that my first attempt was a success, especially considering the circumstances.
Thanks so much for your help mrvedit!! You're a good man!
I did the mods mentioned above and my truck drives like new! I have 2nd and 4th back and they are strong. I have no idea which of the new parts or which mod fixed my problem, but I'm damn glad it's fixed. At WOT, my 1-2 and 2-3 shifts are nice and firm and at low speeds they are nice and smooth.
I had bought a Fitzall Servo pin extender but I broke it in half while trying to hammer it onto my pin, so I ended up welding about a 1/4" blob on the pin. I ground and shaped it to make it about 3/16" longer overall. Luckily, that seems to have been the perfect length.
I also ground a bevel onto the manual shift valve to make it easier to move the shifter when on a hill but haven't had a chance to try that yet.
The only negative thing I have noticed is that when I am in second and mash the pedal, the downshift into first is a pretty harsh but other than that, I think its perfect! For never working on a trans before, I feel pretty lucky that my first attempt was a success, especially considering the circumstances.
Thanks so much for your help mrvedit!! You're a good man!
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Yasin usta (12-24-2023)
09-20-2013, 08:44 AM
#11
Hi MrVedit. Sorry for my delay in replying. I've been to busy driving around with my fixed trans!!
As for what I did to the trans, I installed a Corvette Servo, a Sonnax boost valve, Sonnax pinless forward accumulator, Transgo separator plate (custom drilled), extended the servo pin 3/16", replaced a broken 3-2 spring, beveled the manual shift valve, and replaced all the seals and orings.
Since my last post, I have put almost 10k miles on my truck and it has been driving perfect. It shifts perfectly and has never once slipped, shuddered, flared, etc...
For never working on an auto trans before, I have to say I'm pretty damn proud of myself! However, I do owe a lot to you and the other LS1T members for sharing what you have learned so others can learn it too.
Thanks again MrVedit!
As for what I did to the trans, I installed a Corvette Servo, a Sonnax boost valve, Sonnax pinless forward accumulator, Transgo separator plate (custom drilled), extended the servo pin 3/16", replaced a broken 3-2 spring, beveled the manual shift valve, and replaced all the seals and orings.
Since my last post, I have put almost 10k miles on my truck and it has been driving perfect. It shifts perfectly and has never once slipped, shuddered, flared, etc...
For never working on an auto trans before, I have to say I'm pretty damn proud of myself! However, I do owe a lot to you and the other LS1T members for sharing what you have learned so others can learn it too.
Thanks again MrVedit!
09-20-2013, 08:03 PM
#12
Moderator
You should be proud of yourself! Congratulations.
Helping people like you is the main reason I participate here and experiment with my own transmissions.
Getting another 10K miles on that "patch" is awesome! However you probably will need a rebuild soon, at least a new band. If you want to tackle that I and others will help you with that too.
Helping people like you is the main reason I participate here and experiment with my own transmissions.
Getting another 10K miles on that "patch" is awesome! However you probably will need a rebuild soon, at least a new band. If you want to tackle that I and others will help you with that too.
04-27-2014, 03:24 PM
#13
Teching In
Join Date: Jul 2011
Location: Oregon
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I have a similar problem: "I just lost 3rd and 4th gear in my transmission, it will shift into but not hold when I give throttle. I have a 1998 Pontiac Trans Am with the 4 speed automatic code #GU5. Does anyone know the best solution for this or know of anyone parting out their A4 LS1 Firebird/Trans Am/Camaro with the GU5 Transmission? Any help is greatly appreciated, thank you."
