T56 Rebuild "how to" write up
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This is likely your problem. I doubt the spring on the rear side is under one or more of the keys so they're not allowing the gear selection. You should have moved the selector up and down after installing the keys to make sure it works.
#242
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T56 Rebuild "How To" Write-up
T56 Service Manual
Disclaimer: The following is for informative purposes only and not intended for use. Under no conditions will the author, ls1tech.com or other host be held liable for use or misuse of this information. Always maintain safe practices, use jack stands and follow tool manufacture's prescribed instructions. Do Not Attempt.
- Torque wrench
- Punch set
- Good Snap ring pliers
-inner and outer, Sears carries a decent selection - Jaw Pullers, at least 6" & 8"
- T40 torx bit
- Assembly lube/grease
- 2.5" PVC pipe
- Marker
- 4qts ATF + some to soak the blocker rings, either save some that came out or another qt.
To lighten things up, drain the transmission, use a 3/8" square ratchet.
The T56 holds 4qts of fluid (4.1 or 130oz). ATF Dextron/Mercon III, IV is a revision and is compatible.
"Until the mid-2006 model year, all six-speeds will be produced filled with DEXRON III fluid, although the transmission has been validated for used with new DEXRONŽ VI. In mid-2006, the six-speeds will come filled with DEXRONŽ VI, which was developed to behave more consistently during temperature and other environmental variations, as well as to provide even lubrication of the moving surfaces of the transmission."
-SIX-SPEED MANUAL TREMEC T56 (MM6/MZ6//M10/M12) CAR TRANSMISSION 2006 Model Year Summary-
The T56 holds 4qts of fluid (4.1 or 130oz). ATF Dextron/Mercon III, IV is a revision and is compatible.
"Until the mid-2006 model year, all six-speeds will be produced filled with DEXRON III fluid, although the transmission has been validated for used with new DEXRONŽ VI. In mid-2006, the six-speeds will come filled with DEXRONŽ VI, which was developed to behave more consistently during temperature and other environmental variations, as well as to provide even lubrication of the moving surfaces of the transmission."
-SIX-SPEED MANUAL TREMEC T56 (MM6/MZ6//M10/M12) CAR TRANSMISSION 2006 Model Year Summary-
Disassembly:
Remove shifter:
Remove the 4 hex perimeter bolts and remove the entire shifter as a single unit
Punch out Roll pin in shifter saddle and set aside.
Punch out Roll pin in shifter saddle and set aside.
![](http://img134.imageshack.us/img134/1355/20885778ki4.jpg)
Remove:
vent tube bracket and vent tube
(11) 5/8" bolts from the adapter plate- behind slave
-leave 1-2 bolts part way in and pry the plate loose using the designated prying notches
(11) 5/8" bolts from the adapter plate- behind slave
-leave 1-2 bolts part way in and pry the plate loose using the designated prying notches
![](http://img207.imageshack.us/img207/8220/88894070yd0.jpg)
Stand transmission up with the input shaft facing down,
-put the input shaft through a hole in a table, the bellhousing and a couple blocks also works
Remove:
(8) 5/8" bolts from the tail-housing and lift tail-housing off
Start tearing down the beast:
Remove:
Rubber seal
Snap ring
Vehicle speed rotor, use gear puller
Snap ring
Snap ring
Vehicle speed rotor, use gear puller
Snap ring
![](http://img134.imageshack.us/img134/8769/68637072nq0.jpg)
-a bit down the shaft
snap ring
spacer
bearing, roller type
spacer
snap ring
(74) thrust washer
(73) gear, reverse
(72) bearing, reverse needle
(71) wave washer
(70) brass blocker ring, for reverse gear
(69) Snap ring
(68) thrust washer
(67-62) Synchro Assembly
spacer
bearing, roller type
spacer
snap ring
(74) thrust washer
(73) gear, reverse
(72) bearing, reverse needle
(71) wave washer
(70) brass blocker ring, for reverse gear
(69) Snap ring
(68) thrust washer
(67-62) Synchro Assembly
![](http://img134.imageshack.us/img134/3171/78276148sp0.jpg)
5/6 gear removed
Remove
Snap ring, above the reverse fork, pull up on the synchro sleave and fork and take off as a single unit, set aside.
(61) 5/6th gear
Snap ring on 5/6th fork
Countershaft extension and 5/6th fork as a single unit, (Note the orientation of the thrust washer under the countershaft extension)- set aside
Remove:(61) 5/6th gear
Snap ring on 5/6th fork
Countershaft extension and 5/6th fork as a single unit, (Note the orientation of the thrust washer under the countershaft extension)- set aside
(2) T40 torx, shifting guide bolts from the side of the transmission
(4) bolts and take off the shift guide plate
(4) bolts and take off the shift guide plate
![](http://img134.imageshack.us/img134/7499/25783706xz4.jpg)
![](http://img207.imageshack.us/img207/5304/41875035mr3.jpg)
after the guide plate is off, punch out the rolling pin holding the front offset lever (below)
![](http://img516.imageshack.us/img516/4791/82899969vz0.jpg)
Now we are ready to take off the main case.
The underside of the front offset lever contains a spring loaded ball that rides in the shift detent assembly. When pulling the main case off, hold the end of the offset lever down as the shift rail comes out. It's easier and also helps the ball not go flying off somewhere.
Slip the main case off.
![](http://img134.imageshack.us/img134/8125/82880494yl6.jpg)
Take a moment and look how the shift selecting pin and interlocking plate work together.
![](http://img207.imageshack.us/img207/9628/62144471ju6.jpg)
Note the vertical slot on the 5/6th shift rail lever (left,#144 slot not shown) and the horizontal slot on the interlocking plate (right,#156). We'll have to line these up when the shift guide bolts go back in.
Remove:
5/6th shift lever and rail as one unit.
-You can just go at it from here, but everything comes out nicely if you'll slide the sychro sleeves towards the up position. The countershaft then can easily be slid out.
Mainshaft, shift rail and forks, take out as one unit. Note how it looks, this will go back in as one unit.
-You can just go at it from here, but everything comes out nicely if you'll slide the sychro sleeves towards the up position. The countershaft then can easily be slid out.
Mainshaft, shift rail and forks, take out as one unit. Note how it looks, this will go back in as one unit.
From here the mainshaft must be take apart from both ends, a divider can be seen after removal of the 3rd gear.
Flip the mainshaft upside down on the stubby end, (right side of pic below)
-leave the bearing on unless you're replacing it.
![](http://img134.imageshack.us/img134/7638/10ho7.jpg)
(Starting left- large tapered bearing, 1st gear, 1/2 synchro, 2nd gear, 3rd gear, 3/4th synchro. Divider pointed out)
Remove:
Snap ring
3/4 synchro
-Pull 3/4 synchro sleeve off, either tap it off or use a puller
-Pull the synchro hub with a gear puller
Blocker ring
3rd Gear and caged needle bearing, (keep up with the bearings and where they go)
Spacer
Now we're done with the stubby end, flip the mainshafter over.3/4 synchro
-Pull 3/4 synchro sleeve off, either tap it off or use a puller
-Pull the synchro hub with a gear puller
Blocker ring
3rd Gear and caged needle bearing, (keep up with the bearings and where they go)
Spacer
Remove:
Rubber o-ring, use a very thing tool and carefully remove it, use care not to tear it.
Bearing, (large tapered bi-directional load, input shaft)
1st Gear and caged needle bearing
Snap ring
Thrust washer
Inner cone
Friction cone
Blocker ring
(1/2) Synchro, again remove sleeve then use a gear puller for the splined hub
-Kent-Moore offers a long gear puller for some $$$, but if you're a budget racer like myself, if you're rebuilding your own transmission you probably are, then you can improvise.
Shown below, a couple of 8" and a 6" pullers combined
Bearing, (large tapered bi-directional load, input shaft)
1st Gear and caged needle bearing
Snap ring
Thrust washer
Inner cone
Friction cone
Blocker ring
(1/2) Synchro, again remove sleeve then use a gear puller for the splined hub
-Kent-Moore offers a long gear puller for some $$$, but if you're a budget racer like myself, if you're rebuilding your own transmission you probably are, then you can improvise.
Shown below, a couple of 8" and a 6" pullers combined
![](http://img207.imageshack.us/img207/8366/11lf1.jpg)
Tape them so they'll stay together. (Jimmy rigging this sucks, the_merv builds a better unit on pg5)
![](http://img134.imageshack.us/img134/8939/12hu7.jpg)
note, the 6" puller is oriented wrong in the first pics
Continue removing:
Blocker ring
Friction cone
Thrust washer, (looks like a sprocket)
2nd Gear and caged needle bearing
Mainshaft Disassembly complete:Friction cone
Thrust washer, (looks like a sprocket)
2nd Gear and caged needle bearing
Back to the Countershaft Extension:
![](http://img134.imageshack.us/img134/4973/13xm6.jpg)
Remove:
Thrust washer, (should have already been removed when extension came out, black thing at right end of pic)
6th Gear and needle bearing
Blocker ring
Spacer
Snap ring
Synchro Assembly- (again tap off sleeve and pull the hub, separated sleeve and hub shown below)
6th Gear and needle bearing
Blocker ring
Spacer
Snap ring
Synchro Assembly- (again tap off sleeve and pull the hub, separated sleeve and hub shown below)
![](http://img134.imageshack.us/img134/1708/14au5.jpg)
Continue removing:
Blocker ring
5th Gear and needle bearing
Countershaft disassembly complete:5th Gear and needle bearing
Synchros:
Lay the snychro hub down flat and put the keys into place.
-Notice there's there's humps on the back of the keys, now look at the sleeve; there's indents on the sleeve where the keys must go.
Put a spring into the slot of a key and go either direction.
-The springs are all different, but go according to size of the synchros. A large, medium, and two smaller sets.
-If you're using billet keys, there won't be a slot in the key, go just past the key for spring placement.
-The springs go 2/3 the way around, therefore both sides must go the same direction for whichever direction you chose.
Flip the synchro over, start a spring and go the same direction.
-Notice there's there's humps on the back of the keys, now look at the sleeve; there's indents on the sleeve where the keys must go.
Put a spring into the slot of a key and go either direction.
-The springs are all different, but go according to size of the synchros. A large, medium, and two smaller sets.
-If you're using billet keys, there won't be a slot in the key, go just past the key for spring placement.
-The springs go 2/3 the way around, therefore both sides must go the same direction for whichever direction you chose.
Flip the synchro over, start a spring and go the same direction.
![](http://img207.imageshack.us/img207/1792/15lp2.jpg)
-There's slots on the blocker rings that must line up with the keys upon assembly, it's self explanatory when you look how it goes together.
-You'll notice in the pics that I've marked all the blocker rings and synchro sleeves, so there's no guessing involved.
The reverse gear synchronizer key retainer:
The reverse gear only engages only on one side, and can be flipped over during install for the fresh face of the sleeve which provides better engagement. Thus, there is a key retainer in place of the blocker ring on one side. See: Service Manual: page 29, part #67
do you have the pictures?????
#245
9 Second Club
#246
#247
9 Second Club
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But there are videos with more than enough information for anyone with half a wit to be able to use the information to rebuild
#248
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can you post some links looking to upgrade my tranny over the winter
#249
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I need to reseal the tailshaft housing on my t56. Can the tail housing be removed from the transmission while it's horizontal? I'd like to avoid having to drop out the tranny. The manual says to remove the tailhousing with the trans vertical and the input shaft facing down. Just wondering if something will fall out or get misaligned if I just pull off the tailhousing with the trans in the car.
#250
9 Second Club
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I need to reseal the tailshaft housing on my t56. Can the tail housing be removed from the transmission while it's horizontal? I'd like to avoid having to drop out the tranny. The manual says to remove the tailhousing with the trans vertical and the input shaft facing down. Just wondering if something will fall out or get misaligned if I just pull off the tailhousing with the trans in the car.
It may be slightly trickier getting it back together, but it wouldnt be impossible.
#253
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Originally Posted by srracer
Part 1 - Initial tear down of the T56 Transmission: https://youtu.be/u4eiuwXN6QU
On this tranny I've got, I used my brand new cordless impact to knock the nut off, and then was kicking myself because I had forgotten to go to Autozone to rent their loaner 3-jaw puller. But I grabbed the flange and much to my surprise it came off by hand - slipped right off the splines with basically no effort at all. Is that flange supposed to be a tight/press fit onto the output shaft splines?
Last edited by AAIIIC; 05-07-2017 at 05:53 AM.