jameso1985

recently purchased a t56 w a good amount of shaft play on the input shaft.. was thinking of replacing myself. anyone know how difficult it is to pull main shaft apart?

1madss

iTrader: (10)

Do you mean that you can move the input shaft up and down when the transmission is horizontal (running position)? If so this is normal. The pilot bearing holds the input shaft in position while running.

BTW: You can download the T56 service manual from the Tremec web site for information on how to disassemble/assemble the tranny.

99ssleeper

iTrader: (98)

to get the input shaft out, you would have to take the trans out, take the extension housing/internals out, and take main case off. then remove the countershaft and pull the main shaft and forks out. then you can pull the input shaft out of the front plate. there is a writeup on here for trans disassembly... or check this writeup on ls2.com..

http://www.ls2.com/forums/showthread...&threadid=1877

i wouldnt expect any play in the input shaft, mine had none in any direction.

1madss

iTrader: (10)

Call a reputable shop and ask them. No play means bearings are too tight.

99ssleeper

iTrader: (98)

well since my trans had never been apart before i installed new synchros, and all the bearings looked very good, i would say no play is the way they should be. if there is play the front seal is going to distort and leak.

should the tailshaft have play as well? how about the pinion yoke on the rearend? i think not.

85MikeTPI

iTrader: (9)

Links to T56 rebuild articles

1madss

iTrader: (10)

Not looking to argue. I'm just telling you what every shop that I have ever asked this question to has answered. It's no just an impression that I have come up with.

Again just call someone that does makes their living of doing. Either D&D or Tick would be a good start.

The mainshaft has a bushing in the extension housing that serves to hold the shaft in place. The same function that the pilot bearing serves on the front end og things. Therefore, Little deflection in the mainshaft.

bearcatt

iTrader: (41)

What is a good amount of shaft play ?


The rebuild manual calls for .000 to .002 .



.

99ssleeper

iTrader: (98)

im not trying to arguing either. i just think an input shaft with "a good amount" of play is not the way they are supposed to be. spec on mainshaft endplay is .000-.002" which would not allow much if any play in the bearings.

jameso1985: there is a tapered roller bearing in the front plate and there is a tapered roller bearing inside the input shaft that the mainshaft sits into. then there is another tapered roller bearing on the mainshaft at the back of the main case. the mainshaft and input shaft are fully supported. how much up and down play is there?

this is an interesting topic...hope some rebuilders chime in for more info.

thesource

iTrader: (60)

FWIW, I set my units with a slight bit of preload. How much is a secret

jmd

iTrader: (4)

Endplay of .000 doesn't equate to zero or even .002 lateral play at the pilot end of the input.

The T56 mainshaft length and support bearings preclude the output from moving as much as most automatics, for example. But, the slip yoke bushing in the tailhousing is again there for the reason of acting to minimize lateral play.

99ssleeper

iTrader: (98)

Alright, what does it equate to? It sounds like you have experience with this, but please share more. The front tapered roller bearing is small but the input is captured between two of them. If the input does move, that means the mainshaft will move as well, in the opposite direction.

Correct, since theres about a foot of unsupported mainshaft from the rear of the main case to the tailshaft, I would expect there to be some support there given the weight of the mainshaft.

The question is still: How much is a "good amount" of play? 1/8" up and down? More? Less? If lateral movement is only .010" then sure, I can believe thats possible, but .010 is not a "good amount" of play to me.

??

jmd

iTrader: (4)

The input shaft lateral play while free of the pilot bearing is not a measured spec. for which numbers need determined. You're literally asking for a spec. to be provided for an unassembled unit.

The things that do need done are the verification that the bearings are in good operating condition (or replacement) while the trans. is apart and the endplay verified or set properly. And a new pilot bushing or bearing.

99ssleeper

iTrader: (98)

Im not asking for spec, I'm asking approximately how much movement there is. Anyone who can R&R a trans should be able to distinguish between .010" and .125" play. And this lateral movement would be measurable since it depends on the tapered roller bearing preload.

jmd

iTrader: (4)

Then you should start up your own thread and take a poll. No sarcasm intended.

99ssleeper

iTrader: (98)

The person who started the thread should chime in and say how much it moves. It would take 2 minutes to get an approximate measurement and it would be helpful to anyone with same issue/question.