Rear Lockup Issue

[NodakDSM]

So, we finally got the clutch issue sorted on my 96 Talon TSI, and a new problem rears its ugly head. The car goes into every gear with no issues now after new clutch install. We getting ready to take it home and encountered the following. First gear accelerate fine, shift to second. Accelerate to around 25 mph and got a strong shudder followed by the rear tires locking up. Put it in neutral and got out to look underneath. No fluid, nothing hanging. Put it in first and headed back to the shop at 10 mph. Everything was turning fine. Poof, rears lock up again. Put the clutch in and stopped. Released the clutch and it moved fine again.

Some backstory. This car has been sitting for over 8 years. The brakes may be locking up without pedal input, but unsure. I bought the car as it sits, so I have no idea what all was wrong when it was parked and have been tackling things one step at a time. When we replaced the clutch we were unable to separate the driveshaft from the transfercase. Just removed and reinstalled in one piece. The car rolls and drives at low speed with no issues, but as the speed increases the problem arises. Where should I start? This is my first DSM and my first awd car. Any thoughts or advice would be greatly appreciated.

 

[DSMPT]

Sounds like some kind of failure on center diff or t-case or rear diff. Are you sure the t-case and the rear diff are not dry? have fluid?

 

[NodakDSM]

That is one of the things I will be checking tomorrow is fluid level and quality. Just wondering how to check the mechanical workings.

 

[bastarddsm]

Put it on 4 jackstands, neutral, and rotate the rear tires 10 turns. Have an assistant, make sure the fronts turn 10 turns too.

 

[NodakDSM]

And I'm a moron. Too much time with fwd cars I think. The car had bald tires on the pass front and drivers rear, brand new tires on other two. Rotated the new to front and bald to rear. Pretty sure that is my binding issue. New tires be installed as we speak. Changing rear diff fluid also. If you spin the driveshaft, the pass front and drivers rear both turn at same speed. So hoping the tires are the main issue and I didn't break something else .