WackyRotary

Setup: Turbo'd 12a/stock tranny/LSD rear end. This isn't the "ideal" setup being the power overpowers the drivetrain somewhat, but I don't need to be told that!

Having said that.....
Not sure whats wrong exactly. This car is stored during winter- I took it out for a short spin today to run it a little. Strong boost and power probably help accerate the car as well as accerate the rate at which the problem occured. Haven't had a lot of time(car is stored 70miles from my home), but looking for causes or those who can relate to my issues with my car and provide possible insight. I have determined the transmission is operating normally. Shift and goes into gear as normal with engine running and clutch engaged. I know what a bad transmission does and does not do!

As for the rear end- heres whats going on: I raise the rear end up with the engine off, spin the wheels foward/rearward by hand, and a clunk is noticed. Occationally spinning the wheel in reverse, it hits a spot were the tire dead stops unless you shake it around a little to free it. The rear left wheel seems more noticable then the other. This is a LSD unit- both tires are moving same direction and that seems to be operating correctly. But, when drive the car across the driveway at my house (the clunk is too loud to tempt fate driving it this way and possibly break down away from home) it makes bad noisy clunks- more so in forward.

U-joints on the driveshaft appear to be in good working order- however its not confirmed yet- being I didn't have a lot of time to diagnosis the problem. But U-joints cause bad vibration, and I didn't encounter that up to today.

Thanks in advance for all insight!

aussiesmg

iTrader: (1)

Either axle has broken at spline or the gears on the pumpkin, you need to remove the pumpkin and check, check the axles thoroughly also. Replacement should be cheap, just find a low milage or automatic diff so it hasn't been thrashed.

85TIIDEVIL

iTrader: (2)

Isn't the plug on the center bottom of the rearend housing magnetic..? Pull it and see if there's a chunk of metal or any signs of worn metal in the gear oil for a heads up.... I'd bet a tooth or two are wasted on the ring and pinion.

steve84GS TII

I concur,either axle or ring and pinion.....

WackyRotary

Thanks for the possible causes guys. I will give a update when I findout what exactly has happened.

WackyRotary

UPDATE: Just put in a new/actually older rear-end in my car. $133 after tax. Found the issue for the pinion/ring with bad teeth-I will get pictures eventually and post in this thread. Is there anyone that needs the LSD clutch-section possibly or rear axles for a '84-85 rearend.

I found a junkyard that actually had a LSD rear end from a '81 with 140,000miles. The unit was insanely muddy and the junkyard guys plasma cut off the shocks, torsion bars, etc. All the bolts required cheater bars and then some to get them off! Luckily I ended up with a good working unit after finally getting all the mud off. The fluid inside was very clean, so I suspect this unit was well taken care off before the car was orginally dropped off at the junkyard. There was almost no play in the axle, I am very satified.

I noticed that the flange that connects to the driveshaft was different being I had just put in a '81 rear end in my 84 model. I checked the forum and found out you could simply swap the flange on the end- which was very easy. The seal was intact, so I simply put it on and torqued it to spec for the correct pre-load. This place CAN be a good resourse. -THANKS