lag in awd

[Sp1kE]

My car: 90 tsi awd
Has always had a thump when changing gears.
Or something loose in the drive terrain.
When I put my new clutch in I noticed it more.
It sounds like it is comming from the rear end.
I read the VFAQ and put silicone in my worn driveshaft mounts.
Did nothing.
When I was under the car I could spin my drive shaft about an inch either way.
(I assume thats not good)

I've drove around like this for 2 seasons now.
When I first had my car out it had the transfercase recall. but apparently dealer said it was fine.
About a month later I took off my transfercase.
It was so dusty and hard to get the bolts out.
Looks like It has never even been pulled!
I think the Dealership just said it was fine.
But the dealership shut down and I couldnt go back.

Im thinking it is my rear diff or my transfer case.
How do I check either one?


Thanks,
Mike

 

[hopwoodp]

Check both for cracks or leaks. Then, drain the fluid and look for metal shavings or possibly chunks of metal. Replace the fluid levels and clean the rear diff and transfer case and again look for leaks.

When my transfer case blew, it had a 6 inch long crack on the bottom. I knew when it broke, it sounded really bad. It sounded like a put a bunch of silver wear in my dryer and ran it for a couple seconds. You would know if this went out. Not to mention you would have power in your front two tires and not the rear.

 

[Sp1kE]

OK, Car still flys, I jsut went to the track and pulled low 13's with it like that.
I have changed the transfercase fluid and there are no metal shavings, I Topped up the rear diff, but never drained it....

It sorta seems like the rear end doesnt start turning the same time as the front.
If i go slow when shifting and ship the clutch a bit, it doesn't happen.
but if i pop the clutch out i can hear drive shaft go hard and the back end kicks in.(big knock)
I'm pretty sure its the inch in the driveshaft I can turn either way.
but all the knuckels are solid.

Thanks for your help, I will drain fluid tonight.
Anyother places I should look?

Thanks,
Mike

 

[AJGoldie]

I have this same problem. Havn't really looked into it tho since I have only had the car a week. My friends trans am had the exact same problem and it was just a tranny mount.

 

[mach4g63t]

I remember seeing a thread in the newbie forums about some guy who was having a similiar problem. Turns out his drive shaft was loose on the back end and the drive shaft popped out and hit the ground or something. Fortunately he was just pulling out of his driveway, but you could imagine the damage if it was spinning fast at highway speeds.

 

[Sp1kE]

ya i checked all the connections in the driveshaft.
They are all solid.
It has to be the rear diff or the transfercase.
When I had my tranny out I painted my mount and there was no wear.

Ohwell one more track run this year then car goes away.
I will investigate more this winter.

 

[hopwoodp]

ya i checked all the connections in the driveshaft.
They are all solid.
It has to be the rear diff or the transfercase.
When I had my tranny out I painted my mount and there was no wear.

Ohwell one more track run this year then car goes away.
I will investigate more this winter.

What about the viscous coupling or center diff? If it is still not driving right, you may need to check this stuff out.

Jack up one end of the car and put it in gear. Turn the end that is jacked up and see if it "slips" and listen for any unusual noises. try this on both ends and see what comes up. I am sure there are other variations out there. Like, put both front and rear on jacks and turn a tire and see if the opposite end turn.

 

[Zenja]

The rear diff probably has excessive play. It can be rebuilt.