Early Quattro electronic diff

[zac510]

The subject matter is Audi 80 electronic differential (and 100/etc that I think also came with it). I have read a little bit around on the net and discovered that some have manual electronic locking of the centre diff and rear diff.

The question is the reliability of the thing - 15-20 years later, how many cars stil have working diff locks?

And how would you suggest one tests for a working system when test driving a car to buy?

Thanks for your help.

[silver bullet]

I used to have an 'A' reg Audi 80 quattro. I had it for 11 years it was a brilliant car. It had the centre and rear diff locks. The centre one worked fine, I never had a problem with it in all that time. The rear one never worked. I got a price to get it fixed but TBH I did not think it was worth it, as I could get anywhere I wanted to go with just the centre one. Bearing in mind I am in Cumbria where we measure snow in feet not cm's and I am a farmer so it got plenty of chance to go off road
To test whether the diffs are working you could find a bit of grass, pull out the diff lock button give it some revs, and see how many wheels are spinning. With the centre locked you should have one front and one rear and if you pull the button all the way out it should be one front and both rears.

I would recommend the 80 quattro to anybody it was one of the best cars I have owned but, if you are going to buy one second hand check the service history. If it has been maintained properly, fine, but if not you are looking at quite a bit of money to put it right, believe me I know

[johnh875]

That's a tough one - perhaps there is an Audi specialist that would be able to check it out?

[zac510]

thanks sb. The best way to test it would be to jack up the rear wheels, lock the diff and check that they turn the same direction by hand but this can be a bit hard when you're inspecting somebody else's car!

[silver bullet]

Originally Posted by zac510

thanks sb. The best way to test it would be to jack up the rear wheels, lock the diff and check that they turn the same direction by hand but this can be a bit hard when you're inspecting somebody else's car!

That would not work, because as I understand it, with the rear diff locked the centre one would also be locked, so a front wheel would also need to turn.

[zac510]

So you can't lock them independently?

[silver bullet]

On the one I had, there was a button in the dashboard. When you pulled it halfway out it locked the centre diff, and the whole way out locked the centre and rear.

[zac510]

I see, thanks

[zac510]

While we're here sb, do you have any knowledge on which engine is most reliable?
Through the 80 and 100 models there seems to be a 1.6, 1.9, 2.2, 2.3, 2.6, 2.8!

Kind of hard question, I know, but is there a 'pick of the bunch'?

[silver bullet]

Mine was a 2.2. It never ever let me down even though I gave it some serious abuse. It was also economical, if you drove it properly. Mind you if you gunned it you would think there was a hole in the tank

So I would probably go for the 2.2 as it almost bulletproof.

[zac510]

Another question - did any of the non-quattro models have the lockable rear diff too?

[johnh875]

Non quattro would be front wheel drive only, unless I'm missing something

[zac510]

Right thanks - we never actually got to even looking at an Audi. We've got a car now.