Brando5641

iTrader: (3)

1999 trans am m6

OK i just bought the car like a week ago and the guy said it had a rearend whine well..... its not the rear. The tranny has a realy loud whine at like 35+ mph and is real pronounced when you just tap the gas and put just a tiny amount of load on the tranny. It does it in all gears and gets higher pitched the faster you go.

Bearings?

85MikeTPI

iTrader: (9)

How did you prove that it's not the rear? A rear gear whine will travel up into the cabin in the same spot as the trans and is often mis-diagnosed..

If you're sure it's the T56, does it change at all in 4th gear? If so, it might be the pilot bushing/bearing or the pocket bearing on the mainshaft. If it's the same in all gears, look at the input shaft bearing or any of the countershaft or large main bearings..

Brando5641

iTrader: (3)

If i hold my head by the shifter it deff. sounds like the tranny. 4th is just as loud as the others

Brando5641

iTrader: (3)

It's only doing it when very very light pressure is put on the clusters.

thesource

iTrader: (60)

If its making noise in 4th, I doubt its anything inside the transmission. By the way, bearings do not whine. They growl. Gears will whine but a T56 transmission will not have gear whine in 4th gear.

Brando5641

iTrader: (3)

ok so how am i going to pinpoint this? If i jack the rear up i dont think i will hear anything b/c there is no load

Edit

It sounds like a realy bad vibration whine....

Brando5641

iTrader: (3)

Nothin?

jmd

iTrader: (4)

stethoscope.

Zabo

iTrader: (3)

I'm getting a similar whine in mine but it's like a really bad power steering pump whine. Only occurs in turns at low RPMs in 1st, sometimes 2nd. I can never get a clear recording of it either so I just use the PS pump analogy.

I'm assuming this is the typical GU6 3.42 whine coupled to the G80? Noise really does travel in these 4th gens so that's what I'm sitting on right now. It does it intermittently too (temp based from my experience). Shop that inspected it before buy thought it was bad bearings 1st through 3rd gear. Trans shop said it was the rear end being the rear end.

I'm not sure so I thought I'd just toss it out there for anyone whose seen this before (8 months into this car so I'm still learning it's quirks plus it sat forever).

However like everyone else says it always sounds like its coming just in front of the shifter linkage. Maybe if we get an answer probably toss this into the Manual trans FAQ sticky?

wrd1972

iTrader: (12)

When I recently rebuilt my T56, I found that the main shaft bearing clearance was about .005" or so. Ideal bearing clearance according to Tremac is .000" - .002" of bearing clearance. I set mine back to .001" or so. I have no idea what wore or loosened up to provide that measurement.

Before the rebuild, the tranny was noisy especially at low speed, low RPM conditions like miking slow tight turns. It had that gravel in a shoebox sound. There was also some very faint but noticeable whine coming from the tranny too under various conditions.

After the rebuild, it was much quieter than before and the gravel in the shoe box sound is almost non existent. I feel by tightening up the clearance, it made the tranny more quiet.

Also I did not replace the bearings or races. Just tightened up the main shaft clearance.