Rearend the Culprit?

Hi, I now own the 1992 SC that lon was having the problem with the powerloss. He said it happened when he did a burnout once. Went to do it again and it wouldnt spin the tires over. He re-did everything on the engine and replaced/checked all things you guys said could be suspect. When I got it, I adjusted the TV cable and got it to shift where it should. It still has the problem of Geometroidus(aka no balls) out of the hole. I was wondering if maybe the rear end was causing the extra drag on the engine. Could this be it? I jacked the car up and tried to turn the rear wheels in neutral and got them to spin. It took some effort to get them to go, and I could hear an almost grinding-like noise coming from the rearend. Is there anyway to check/add oil or grease to the rearend and see if that helps? Any info on this situation would be greatly appreciated! Thanks in advance!

~Eric

Grinding noise = something is broken. Sounds like you found the problem... you can disconnect the driveshaft and try turning the wheels by hand again to help pin it down. A slight scraping noise from the brakes is OK, anything else is not. Also, there is a 4 sided screw-in plug on the back side of the diff case where you can check for and add oil.

Let us know what youfind out. My car did something similar at the Shootout and I'm convinced my problem is the torque convertor, but I have not had a chance to check anything. I'd be elated if the differential was the problem.

Will do guys, I'll keep you updated. And as far as the noise, its not more like a whirring noise with a slight grind, but in any case i know it isnt the brakes that its coming from. It sounds like its coming from the pumpkin. Sucks, because that rearend has 3.73's in it, and i'll have to buy new ones

I would guess that if something in the rearend is causing enough drag to slow your car down like that, it would be smoking hot after a drive. Is it getting hot at all?

eww, good point. I dont believe its getting hot, and if it is, it hasnt smoke or gotten red or anything. Man this is confusing stuff. I dunno where to turn to next. I know for certain its not a boost leak. I have good readings at idle, park and when im driving.

yea it would be smokin hot and so loud you prob couldnt drive it , it would sound like an airplane or fire engine type grinding . im thinking something wrong in tranny maybe first gear is gone and starting out in 2nd . the only other thing i can think of is when my hb went bad it twisted enough to run like junk , it had no wobble at all . it ran fine just no power as it got worse it would barely go uphill , even rev up slow in neutral