mark b

I recently had the diff and axles done.. everything was fine and after a few months I recently felt a vibration, I thought it was a wheel balance issue.
Then I felt the vibration through the gas pedal.. still thought it might be a wheel balance issue..

Then I shifted to fourth from about 70 and when I let out the clutch and gave it gas (not pushing on the pedal hard) all hell broke loose!

a lot of loud clattering and I pushed the clutch in slowed downed and put it into third, that was quiet but it was still clattering around in the back if I tapped the gas... so I pulled over and put it in first and the car wasn't going anywhere..

Is it the tranny? the diff? the shifter works and goes into all the gears, nothing frozen.

when I keep the clutch in the engine starts and runs fine, but when I engage the clutch it stalls out..Im stranded

Got it towed home.. no leaks

somebody experience this? please help so I know what to repair, thanks

CHJ In Virginia

Two things come immediately to mind. 1) Broken output shaft on differential. 2) Drive shaft coupler guibo. Based on the noise you are hearing the coupler is the most likely suspect. When you had the driveline apart, did the couplers get inspected ? The couplers have a history of disintegrating under hard use. Do a search, there are many threads about this problem.

mark b

When I got the diff fixed I replaced the drive shaft guibos as well.. so they are relatively new.. They weren't GM though..

I just did the differential and had a complete overhaul.. WTF?

So I need a new diff?

AzMotorhead

I'd say you need a thorough inspection of your driveline first. Then you can ascertain what is needed

Evilash

Had my guibos replaced and the jackasses installed them in the wrong order so the bit didn't fully seat eating up the torx head and they just called it good enough.
Made the same noise you describe because two bolts backed out and the one bent bolt was getting me down the road. So higher rpms would bounce the shaft disc into the TT.
Had another shop 3 hours away put in a whole new assembly and everything is perfect.

mark b

When the loud clattering happened it all came from the rear of car,
I think it could be the axles or diff. I just had the Vette doctors fix my diff and replace drive shaft couplers about 3 months ago... The car has been running fine ever since then, only tracked it once on Thunderbolt in Nov, and I take it out once a week for some fun spirited driving...

Obviously it happened while having fun with it and driving alittle hard in cold temps. The car was fully warmed up though and running fine when I heard the vibration at first. Thinking nothing of it but maybe a wheel balance issue I drove through it and a half hour later when shifting to fourth is when it all happened..

mark b

ttt anymore opinions on what it might be? thx

JerryTX

Second or third vote for guibos.

mark b

Took it to Vette doctors and yes it was the recently installed guibos..
apparently on a bumpy road at speed I downshifted and the shock loosened up the coupler bolts causing the problem.. need a torque tube...

How are polyeurothane couplers? Would they eliminate the issue with flexing? Is it safe? Or should I just get the GM ones installed?

never thought that heel toeing on a bumpy road/track would do that. I guess car slammed and bounced hard enough to loosen the bolts

ErnieN85

no they were not installed properly. if your using vette doctors take their recomendation. and make sur they use loctite on those bolts this time