sofakingdom

iTrader: (3)

Hi all,

95 trans am, T56. I did a hard 1-2 pull the other day and ever since then I have a "marbles in a can sound" coming from the transmission/bell housing area. It is very noticeable under load but you have to listen very carefully to hear it when not under load. It doesn't seem to change with clutch in/out. Also, the speed of the rattle is dependent on the gear I am in. In first, it is a slow rattle (like maybe twice per second) and it gets faster in each gear until 6th at which point it is very fast and also much louder than in 1st.

The car still shifts fine, no grinding, shaking etc. Drives just like it did before, just the rattling which is quite loud.

I pulled the trans and I don't see anything that is obviously wrong, clutch, pressure plate (centerforce), TOB pilot bushing all look ok. I'm guessing its something internal but I just wanted to check if anyone else has run into similar issues.

Also, I found a lot of threads where people had issues with noise coming through the shifter...this is different, noise comes from underneath.

I appreciate any help...thanks all!

Redbull87

iTrader: (3)

Thats the exact sound i had and it got worse.then suddenly i wouldnt be able to shift.Couldnt find a single thing wrong with the clutch or trans. Turns out it was the flywheel bolts backing out and engaging the clutch surface.Fixed that and torqued everything to spec and that sound is gone.

I still have a noise from my shifter though i cant figure out how to get rid of.

Firebrian

You might find some ideas here on reducing shifter noise. Some of these will no doubt reduce it....though probably not eliminate it.

https://ls1tech.com/forums/manual-tr...ots-ideas.html

Can't help sofakingdom on their problem. But it is concerning that after a single hard 1-2 shift the problem showed up. You would think any problem would be associated more with those gears/bearings....not the higher most gears.

sofakingdom

iTrader: (3)

Brilliant. Thanks for the heads up...I'll check all that when I get home from work.

sofakingdom

iTrader: (3)

Agreed. Very strange that it is present in all gears, but the speed of the knocking sound is proportional to the gear I am in. Thats what makes me think it is internal, since the input and output of the trans are fixed to engine speed/drivehshaft speed respectively. I'm just going to pull of the pressure plate, clutch and flywheel to make sure everything is ok as mentioned above. If no luck I don't know what else to do other than start pulling apart the T56.

sofakingdom

iTrader: (3)

Well the bolts are all tight and everything looks ok around there. At this point it looks like I'll have to tear the T56 apart. Will report back what I find.

Thanks all.

sofakingdom

iTrader: (3)

Finally figured it out. It was the differential. Lost a tooth on the pinion gear. Now to decide whether to rebuild or upgrade.

Thanks all.

Firebrian

Congrats on tracking it down. You'd figure it was caused by the hard 1-2 shift. If you're going to continue to pull hard shifts, upgrading the rear to match the forged 383 engine/trans set up makes sense to me.