Audi 5000 Revival II - Clutch and Axle

The clutch hydraulics are shot. There appears to be a leak from the slave cylinder, and also the flexible hose going to the cylinder. This is a problem, since there is no OEM style replacement option for this hose. However, there is one company selling steel braided upgraded hoses:

This is kind of overkill for a 100hp engine, but I appreciate it. The slave cylinder itself was a pain to change, being corroded inside the transmission case. I had to be mean to it. There is a roll pin that holds it in place:

I happened to use a 3/16" punch that was slightly too small, and it got wedged into the roll pin instead of driving it out. Big oof. After a half hour of wrestling to get my punch back, I used an M6 bolt and a hammer to finally drive out the pin. Even then, the slave cylinder was stuck, and I had to drive that out with an air hammer. Thanks corrosion.

The new slave cylinder went in more easily after cleaning out the mounting hole. Last was the clutch master cylinder, which required a lot of contortion to get to under the dashboard. I didn't take pictures because it just kinda sucked to change. I should have just removed the driver's seat first. But with all the clutch hydraulic parts changed, my brother and I proceeded to waste a bottle of brake fluid trying to get the air out of the system. No dice, the pedal wouldn't firm up and we gave up. I decided to let it sit overnight to see if the air would work itself out naturally, and it did! The next morning I had a perfect clutch pedal.

Next is the axle. The outer boot on the left side was torn. While replacement axles are available, this is a factory axle with only 40,000 miles on it. Replacement aftermarket axles will break long before this one will, so putting a new boot on it is the best option.

I removed the clamps and old boot to reveal a greasy mess, but that's a good thing since the CV joint didn't get a chance to rust from water intrusion. 

 

I made the mistake of trying to hammer the inner bearing race off the axle shaft before I realized there is a special retaining clip that must be pried open first. I must have fumbled with the clip for half an hour before I figured out a way to wedge it open and hold it while hammering on the bearing race. An M7 bolt did the trick. Not fun. 

 

Now onto the cleaning portion. The ball bearings come out like a 3d puzzle, where you rotate the inner race and remove them one by one. Then the race and carrier can slide out. Cleaning the CV joint is like cleaning a bike hub, just with bigger ball bearings:

I used my usual mineral spirits to get them nice and clean. For reassembly, I thinly coated the bearings with motor oil (I could have used the CV grease that came with the kit, but I hate touching that stuff and reserve it for last). Next I had to solve the 3D puzzle in reverse to get the bearings back in one by one:

Then I squeezed the grease packet into the freshly reassembled CV joint, and slid the new boot onto the axle shaft:

 

After hammering the joint back onto the shaft, I finally secured the clamps with a pair of dull end-knippers:

The last step is cleaning the messy CV grease off my tools. Yuck. Cheers.

Audi 5000 Revival I

This is primarily a bike blog, but I thought I'd like to document my current four wheeled project (if only for my own memories).  My brother bought a low mile 1983 Audi 5000 that evidently sat for years and years. 

 

The body and interior are in great shape, but the mechanical condition is another story: 

• The gear shifter can only reach gears 3 and 4
  
• It leaks gasoline
• The hydraulic clutch leaks and doesn't fully disengage
  
• Timing belt says VW Audi on it and is probably the original from '83
  
• Brakes are stiff and incredibly weak
• One of the axles is leaking grease
  

There are a few other odds and ends, but these are the major problems. Unlike bicycles, cars are mostly made of parts that are bespoke to a particular car model. And when a car has been out of production for over 30 years, well good luck finding replacements. Sometimes you even have to custom make your own replacement parts.

After checking the shift linkage, I happened to find a broken link sitting on top of the transmission. I'm really lucky to have found it, otherwise I probably never would have figured out what I'd need to fix this linkage. It's a simple part, basically a 133mm long rod with two socket ends to fit the 10mm ball studs on the transmission. 

 

You know what else fits a 10mm ball stud? Hood struts. I happened to have a pair left over from a Nissan Maxima, which I decided to cut and join together with a coupling nut. First I needed to cut threads onto the strut rods using a die:

To make the replacement shifter link, I just had to screw the ends of the hood struts into a coupling nut until they were 133mm center to center, then lock them down with jam nuts (just like setting a bike wheel bearing):

I'm proud of it, and the shifter feels like new with the replacement rod installed. Next order of business is dealing with the fuel leak. It's coming from the fuel accumulator, which is like a pressure regulator for old Bosch CIS mechanical fuel injection systems. Removal was tricky, since the fuel lines were very rusty and the nuts would not spin off the flare ends.  I ended up cutting off one of the nylon fuel lines and unscrewing the fitting from the accumulator. Then I spun the whole accumulator off the remaining fuel line going to the pump.

I wish I could have used a torch to loosen up the nuts on fuel couplings, but considering that these are fuel lines and there were gas vapors everywhere this would have been the worst idea ever. I ended up bashing them with a hammer and also using a c-clamp axially to free up the nuts. After pressing the fuel fitting back into the existing plastic fuel line and repainting the mounting bracket, the new accumulator is installed (and no more leaks):

There is plenty of work left to do before this car is driveable again, cheers.