[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
Re: Center Diff locking problems in 87 4KCSQ
>It <the front diff lock> will engage _most_ of the
>time at different speeds but when it does it makes a loud "thwang" and
>feel it shake the car.
Check things like tyre diameters (the sum of the two at the front must
be the same as the sum of the two at the back), or more likely, worn
diff mounting bushings.
>Disengaging it can only be done by completely
>stopping the car and going into reverse and coast a
>bit backwards. Others I have spoken with seem to think it is internal in the
>diff from possibly years of non-use and rust. Any other ideas.....?
I had this problem on my 1984 80q (same car). I could only disengage
by dropping into second gear at 50mph, letting out the clutch and
taking my foot off the accelerator. It was usually easier (read less
dramatic) to stop the car, put it into reverse and drive backwards a
When I replaced the rear diff mounting bushes, this problem went away.
The actuator for the centre diff is actually on the rear diff, and a
long bowden cable actuates the lever on the centre diff. If the rear
diff has shot mountings, it puts strain on the cable, preventing it
from disengaging. If you drive in second gear and jab the accelerator
up and down, do you get loud bangs from the rear suspension - that's a
sure sign of rear diff mountings. They are VERY easy to replace.
If all else fails, put the car up on ramps/stands and get somebody to
operate the diff lock and check the lights. You can be under the car
looking at the actuators/levers. Remember it only operates when the
internal locking sleeve is syncronized. You may need to rotate a road
wheel to help it.
1984 Audi 80 quattro
1983 Audi 100 Avant