PDA

View Full Version : Audi Repair Guidance Thread



Al
01-04-2007, 02:56 AM
This is a thread in response to a recent pm and other questions posted elsewhere.

It is well known that Audis are very nice cars to drive and own, but it comes at a price: they are a ***** to repair!

VWVortex and Audi Forums are the best places to find info for my A4. One of the catches is that if you post a thread, you might need to watch it for some time before you get a response or bump it a few times.

For myself, Step one was to get a Bentley's Manual.
Amazon has one for sale (sorry, no pic on this one for an Audi 80)
http://www.amazon.com/Coupe-Quattro-Electrical-Troubleshooting-Manual/dp/0837603757/sr=1-1/qid=1167894066/ref=sr_1_1/104-6117967-3496719?ie=UTF8&s=books

Second, although dealerships and repair shops don't like giving out free info or having their guys talk while on the clock, they are a great source of info. What I usually do is try to catch one of the techs on his way out the door. Once I have the info I am seeking, I usually buy him some food. If you have the audacity to go into a shop in the middle of the day for advice, be sure that you buy a part while you are there. Most of my parts don't come from the dealer, but when the manager sees you at the parts counter, he is more likely to become your friend.

Also, don't buy all of your parts from the stealership. I usually save about 75% by ordering from PAP-parts or Autohaus Arizona.

My A4 is a learning experience.
I have found that there are waaaaaaay too many things to know about it which can be listed in a 1000 page manual. My current issue is the rear diff. All I had to go on was a noise coming from the rear. I put the car on jacks and took a look. Fluid was leaking, so I thought I found the problem. The half-shaft also had some play which confirmed the problem.

I knew I had to remove the diff, but my manual, 1000 plus pages, has only 10 lines devoted to the removal of the differential. The best thing to do that I could think of was to get under the car on my creeper and just look at the undercarriage till I had a really good idea of what to do. I spent more than an hour under there checking bolt types and deciding on the tools I would need.

I removed all of the bolts as I should have and was ready to drop it down, but some of the parts were corroded together. I had to pound at the half-shafts with an air hammer for more than 5 minutes to get them out. I tried the same with the drive shaft, but it didn't budge. From there, I removed the whole drive shaft with the diff.

Here is a typical Audi rear suspension setup. Note the diff housing is very long. The half-shafts also bolt to a flange; no splines.
http://www.car.net.au/glossary/Images/Large/Image96.gif

With the differential on the floor with 5 feet of drive shaft still attached, I decided to deal with the problem the only way I could in my current mind set (throwing-tools-angry). I searched around for the biggest hammer I could find and hit the flange as hard as I could... nothing. Second try..sounds different Third time is a charm! Done for that day.

The next step was to open up the diff.
I pull of one side of the housing and half of the supposedly bad bearing came with it. This is where I am as I type this. I just bought a bearing puller set too.

I ordered two bearings as well as a pair of shaft seals too. If one is bad, the other might need replacing soon. I should have these parts soon.

I also managed to spill fluid all over my work cart when I left the diff on its side overnight. The demonstrated that the drivers-side seal was bad too. The fluid itself was initially dark, but separated into dark and clear fluids. I initially thought the dark stuff was metal filings, but a magnet proved otherwise.