I am in the process of rebuilding a T-56 out of a 1995 Camaro. I have replaced all the bearings, races, bushings, syncros, etc. I am now thrying to shim it using the shim kit I purchased from The Gearbox. The kit sent was not a complete kit and does not have the combo I need for the countershasft and countershaft extension. Does anyone have extra shims from a rebuild that that would be willing to sell me cheap? A complete kit is around $35 plus shipping.

Looking for the following:

Countershaft endplay is around .028 (need a .027 - .028 shim combo)
Countershaft extension end play is .062 (need a .059 - .060 shim combo)
Mainshaft endply is .048 (I have the shims for this)

Thanks.

 

Actually you need a .028-.030 combo for the countershaft. Spec is .000-.002 PRELOAD.
You need a .062-.060 combo on the extension. Spec is .000-.002 ENDPLAY.

Allthough the manual says do the main/input shaft first this is kinda backwards. If you set the main up for .000 and then set the counter for.002 PRELOAD your main is now .001-.002 endplay. I suggest you set the PRELOAD on the countershaft first. Then with the countershaft in the case do the mainshaft. If done to the tight side this will give you TRUE .002 Preload on the counter and .000 endplay on the main. I hope this helps a little!!

 

I was thinking that endplay and preload where the same thing. What you are saying is that they are differant.

Example: If I have 0.050 endplay without a shim installed and want 0.002 "endplay" when assembled, then I would install a 0.048 shim right? But if I have 0.050 endplay with no shim and want 0.002 "preload" when assembled, then I want to install a 0.052 shim. Is this correct?

So if preload and endplay is differant, then I have comflicting data in the manuals I have for rebuilding a T-56. Which one is correct?

1995 Camaro GM Shop Manual shim specs:

Mainshaft: 0.000 - 0.002 preload
Countershaft: 0.000 - 0.002 preload
Countershaft Extension: 0.002 - 0.005 axial play

Tremec T56 Transmission Service Manual shimming specs:

Mainshaft: 0.000 - 0.002 endplay
Countershft: 0.000 - 0.002 preload
Countershaft Extension: 0.002 - 0.005 endplay

Once I figure out which spec to use and understand endplay vs. preload, what would be the ultimate spec to shoot for the three shafts? I'm assuming the transmission case is going to expand some what when it gets hot and I do not want to end up with too much play in the shafts once the tranny warms up.

Thanks.

 

preload = shim large enough to load or apply pressure. This means you would be using a shim larger that the actual gap or play

ie. if you measure a .050" gap and you want .002" preload use a .052" shim.

endplay = you actually have a gap or play between two parts. End play is a measure of this gap.

ie. if you measure a .050" gap and you want a .002" endplay use a .048" shim

 

I wonder why the big difference in the fsm vs the t56 manual. I wonder which is right?? For a box on the tight tolerance you will want the LEAST endplay(.000 or lowest specified) and the MOST preload(.002 or most specified). Im going to be replacing my bent mainshaft tomorrow so I will be searching for the correct mainshaft shimpack I guess.

EDIT: come to think of it I used .0005 (1/2 thousanth)preload on the mainshaft last time and it was ok!

 

how hard is it to press off the gears and stuff to replace all the syncro's? i'd like to rebuild my tranny so i know what condition everything is in, but i'm not sure how hard it'll be to do.

note, i'm a machinist, have full shop access and an arbor press to work with...

any helpfull jigs or hints for me? anybody got a page made up? i downloaded the manual but some of the pics leave some to be desired.

mike

 

If your not doing bearings... A bearing splitter and a deadblow or press for 2 syncro assys. Mabye press or puller for the 5/6 gear. Mine pulled off by hand and there not supposed to. If your doing bearings....well pretty much the same thing with the exception of shims. Do yourself a favor and get the puller for the races in the front plate. Shimming the box is MUCH easier that way! Most of the pics you will need are around the net. Even without pics its not very hard!

 

I purchased a 12 ton floor press from Harbor Freight and fabricated pressing tools from various size metal pipe to press off all the tapered bearings and the main shaft race in the housing. The countershaft race came out pretty easy by tapping on it from the rear. The race in the input shaft had to be removed by welding a bead around the circumference of it down low. When the weld cooled off the race shrank and fell out. All of the other races are loose with shims under them. My 5-6 and speedo gears came off by hand. I had a buddy of mine make me the countershft end play measuring tool in his machine shop and I barrowed a dial indicator from another friend so I could check the clearances for shimming. I also took alot of digital photos as I disassembled everything. They are coming in real handy as I reassemble.

Since I have 2 manuals with conflicting shim specs in them, I decided to call a few people who would know the T-56. I talked to Tremec, D&D Performance, and Rockland Auto Gear and asked them all what they use as shimming specs on the T-56.

Tremec
Mainshaft - (9-10" lb to turn shaft)
Countershaft - (9-10" lb to turn shaft)
Countershaft Extension - (9-10" lb to turn shaft)
The Tremec specs that you can downlaod from their website are:
Main - 0.000 - 0.002 Endplay
CS - 0.000 - 0.002 Preload
CSE - 0.000 - 0.002 Endplay

D&D Performance
Mainshaft - 0.000
Countershaft - 0.000
Countershaft Extension - 0.000

Rockland
Mainshaft - 0.002 Preload
Countershaft - 0.002 Endplay
Countershaft Extension - < 0.005 Endplay

One person tells me to preload, the other tells me to shim for endplay?
I think I will shim everything to 0.000 and call it good. Just too much conflicting data for me.