T-56 problem

[Z Ya Later]

Alright guys, now I'm worried. I drove out to Fresno on Wed. (3 hr. trip) and so far the trip was great...gotta love that 6th-gear cruise . Then, when I got into town, the tranny starting acting up. No performance lag or anything, but the synchro would start making noise if I put the shifter into a low gear while slowing down with the clutch still in. The noise would go away once I let the clutch out, but I'm still worried. Could it be it just needs new fluid (pretty sure the orig. owner didn't change it) or something...worse? If its just fluid, is there any special additive I must get or just Dexron III? Thanks a lot guys.

[tabahr]

I used Trick Shift fully synthetic ATF with a bottle of Duralube ATF treatment. I realize everyone has opinions about adatives but I have experienced running a duralubed motor 200 miles with NO OIL in it. No damage done. I figure the tranny adative must be good to.

[Z Ya Later]

So you think its just the fluid and that will solve the problem? Thanks for the reply Tracy.

[Injuneer]

Not sure I understand what you are saying the noise is. Synchro's would whine when you first move the lever and attempt to engage the next gear.... if they were worn, you might hear the gears "grind" slightly as the next gear is engaged. At that point, the "synchros" job is done, and it wouldn't make any noise until you tried to change gears.

Does what I described above sound like your problem, or is it something else? The T56 has a rattle in the front mainshaft bearing that is very common. Is it possible that is what you are hearing? Or is it possible it is the T/O bearing, since you only hear the noise while you are holding the clutch in, and it goes away when you let it out.

Its always a good idea to change ALL the fluids in a car when you buy it used.... you have no idea if the previous owner did the required maintenance, or if he did, whether he used the correct fluids. I always used Dexron III when I had the T56, and I truely believe all the additives are useless. I also loaned a spare T56 to a friend, he loaded it up with Honda ATF (the alleged cure-all for t56 problems) and it came back to me with a very noisy 4th gear.

[tabahr]

My trans has the rattle in the front main bearing. If i'm puting in a new clutch and have the trans out is it easy to replace that bearing and make it quiet??

[Injuneer]

The loose bearing is very "normal".... mine had it from when the car was new. Rebuilding the T56 is a bear..... you basically have to start from the back and work your way forward, making the input shaft the last piece you come to. When the T56 was first installed in the F-Body, it came with a sticker on the side "Not field serviceable, return to factory." Even GM didn't trust their mechanics to rip the unit apart. Eventually, they provided factory training.

D+D is the best source for T56 parts and rebuilds.

[00 Ragtop Z]

does it sound a little like a whnning sound? how many miles on teh clutch. Might be a clutch problem.

[tabahr]

It is easy to isolate noises between the clutch and trans. Put on the emergency brake and load the clutch without moving the car. Doesnt matter what gear the tranny is in as long as it isn't in neutral. If you still hear the sound it is the clutch. No sound - it is the trans.

Test yours and see where the sound is coming from.

[Z Ya Later]

First off, the noise occurs after the vehicle has been driven for a few (i.e. the fluid has warmed up). Second, when the noise does occur (doesn't always happen, kinda sporadic) you can feel the shifter vibrating. Third, if it is the throwout bearing, would that also cause the grinding sound and slight vibration in the clutch pedal when you start to engage whatever gear you're in? Thanks for all the info.