!!HELP!! B5 S4 WON'T MOVE! Apparently no power to rear wheels :(
 

Hello Audi World community!!

I need your help with my dilema!

I blindly bought a car off the internet after just looking a couple of pictures. Car was listed as STARTS but DOESN'T DRIVE. Car is super clean and in awesome condition, so I didn't think it twice before getting it. (Moog style, from Mighty Car Mods, hehe).

So here's the issue:

This is a B5 S4. The engine starts fine, but when put in gear it doesn't move, it just revs. Something I notice is that when put in gear the car slightly vibrates (very slight shake) as if it was going to move, but it doesn't. You can also barely hear something spinning and rubbing against something, underneath the car. I think close to the center differential. It doesn't sound like metal scratching, just like something touching/rubbing against some surface. However, I looked underneath and the driveshaft doesn't move when the car is in gear. Nor the front wheels (as expected)

I haven't been able to find a lot of information about this. I read a couple of posts from people experiencing similar issues and it turned out to be the driveshaft / propeller shaft that pops out or breaks at the middle, or the axles itself that go to the wheels.

I consider myself an experienced enthusiast. I this is my second Audi. I also owned several VW's throughout the years and I was always able to work on them. But I cannot figure out what the issue is here... I am experienced with engines and forced induction, but not very much with drive-trains, differentials or any of that... therefore I am really oblivious when it comes down to the quattro system https://www.audizine.com/forum/image...s/banghead.gifhttps://www.audizine.com/forum/image...s/banghead.gifhttps://www.audizine.com/forum/image...s/banghead.gif

From what I have read and understand, there needs to be torque on all 4 wheels for the car to move. Which means that if 1 axle is broken, or power doesn't transfer to one of the wheels, the rest of the wheels won't get any power either, am I right?

I did some testing and this is what I found... not sure if it's useful or not.

Aside from confirming that the driveshaft doesn't move when in-gear and wheels on the ground I also tested the following:

- Lifted the front of the car, turned it on and placed in gear. Both front tires move, the rear tires remained stationary on the ground. I touched the driveshaft while the car was in gear and noticed there was feedback. You can slightly feel the driveshaft turning just a little bit, and then it stops. I am wondering if this is because the rear tires were on the ground, I assume that's the reason.

- What I did next was lift the car from the back and manually turned the driveshaft. I confirmed that the rear wheels also moved when manually turning the driveshaft. But I didn't test this with the car on. Note that I had the front wheels stationary in the ground.

- What I did next was drop the driveshaft to inspect it. I removed the exhaust and disconnected the shaft from the center differential and undid the middle bearing, that way I could see if there was any damage at the middle (the part that bends), or right on the connection to the differential, but I couldn't see any damage. The shaft looks fine and axles also look fine.

- While the driveshaft was disconnected, I placed the rear wheels back on the ground and lifted the front again. I blocked one of the front wheels and spinned the other one, I checked underneath and confirmed that the center differential spins, but the driveshaft was not connected anymore, so I didn't know how strong was the differential spinning to the back. I am concerned that maybe the differential is worn out to the point it doesn't put enough power to the rear for the wheels to move.

On a side note, when I first got the car I was able to shift into any gear without pressing the clutch while the engine was on. When that was happening, I couldn't hear or feel anything. The car was 100% stationary without any feedback when going into gear. Few weeks later I tried the same but out of nowhere the car wouldn't shift without pressing the clutch, which is how is supposed to be... and that's when the feedback appeared seeming like the car was trying to move but it just shakes.

I appreciate very much if you made it through my LOOOOONG winded post... my very first post and a long-winded one... I really appreciate any help or advice on what else to test or look for...

has anyone else experience this?

what else can I test?

what is likely to be? the torsen? is it very difficult to remove / replace?

Once I can get my baby to move and drive it for the first time!! It will go directly back to a friends garage to get a massive upgrade!! I have 2 borgwarner K04's and a RS4 clutch waiting for it... then I will be getting the rest of bits and pieces to go Stage 3!!

Thanks in Advance!!!

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