I have been reading up on it, but im not sure what to do. When i push the switch, i hear a CLICK sound in the rear (arent the controls for it under the rear seat or something).. the little lights in the diagram are burnt out, and the ABS OFF light does not go on, so i assume that the diff lock is not engaged.. anything I can do to fix it? Switch bad?? I would like to get it working bec its gonna snow here in germany soon..knowing me I will get stuck somewhere

 

I used the “lock” on my 100Q last week in a snow storm and sometimes it takes a few seconds for the green light and ABS OFF light to com on, I have to roll or drive a few inches. According to my "The Audi Quattro Book" the rear differential lock servo often fails or the hose gets broken. The lock should engage if starting out from a stop, don’t know if you can do it on the “fly”. Also the lock should disengage once over 15mph. The servo is under the car on the differential.

 

Thanks for the info... I will have to look at it, the servo is on the rear diff right? I have not really had a good look at anything down there.. even at a stop, and then start going the abs light doesnt come off or anything... the little diagram is burned out too Something to work on... I will ask this one guy if he has some spare parts.

 

AH HA! It works!! At least i think it does... the ABS doesn't shut off right away... and thats what threw me off.. but after a bit of driving, there popped on the light So, how do you know if it is WORKING heheh.. i couldnt really tell the difference. I love the car so much! I got it to 160 KPH today on the autobahn... gets a little bumpy and harder to control, but at least i can hang with the rest of the germans.. it was almost impossible to do that in my wifes 94 tercel

 

The autobahn... I certainly miss it! I had my first taste last year while on vacation going from Salzburg to Munich!

One street test you can do is put one side of the wheels on ice and the other on pavement. Another test is to lock the differential on loose pavement like sand, gravel, or snow and make a tight turn while a friend observes. If the differential is locked you will see one wheel skid.

If you car is a bit of a handful to control I think you need to replace the suspension bushings. I just had to replace bushings on my 1991 100Q, I couldn't believe the condition they were in.

 

Suspension bushing eh... yeah at low speeds, like 1st gear, 2nd.. the car sorta bounches around a lot. The springs on the car look NEW, but I dunno. Where are the bushings located?? When I go under the car again to clean it up, I will check them out. Also, the car seems to "bounce" when you left off the gas.. i dont know what causes this.. you ever had that happen to you?? How expensive are the bushings?

Thanks for the info on the diff lock.. I will have to try that out There should be enough snow and ice here soon.

 

I think that you have to more specific when you say bounce? The only problem that comes to my mind is defective front struts. If they are more than 10 years old and were never replaced chances are good that they need to be. My car would go into oscillation that peaked around 55mph (~89kph) now that I have replaced them it is a different story.

The bushings are cheap but replacing them is a pain. The rear suspension is a multi link so there are at least 3 per side.

 

Yeah, it has something to do with the clutch or something I think.. bec in gears over 3rd, it doesnt do it as much as say 1st especially.. I dunno. It snowed today in Germany!! And I tried out the diff lock.. NOW A THERE IS A PROB After it disengaged, it sounded like the front left abs sensor was messed up!! ALL 4 ARE BRAND NEW, not even a month old yet! Before I got them replaced, I heard this grinding sound and the abs would keep going on and off.. bad ABS sensors.. so i got them fixed and everything was fine until tonight. I will have to check it out tomorrow, we just got back from Austria from snowboarding... The ABS light is not going on and off like it was before i fixed them, but the grinding now is back on that tire will it ever end!!

 

Might be a bad wheel bearing or bad CV joint. Another problem might be with the brakes, on my car the pads always form a groove and as it gets worn, the ridge will make a grinding noise.

 

I pulled the front tire of yesterday, and to my relief, it was a VERY VERY VERY tiny rock stuck behind the rotor and backing plate.. and thats it Yeah, my rotors are getting that ridge too. I bought some brake cleaner the other day bec I heard salt gets on them too.. Thanks for the info