Audi 5000 Revival IV - Timing Belt

The timing belt on this car actually doesn't look too bad, but without documentation of a recent change I really can't trust it. This will leave you stranded if it breaks, and potentially damage the engine. Audi mounted this 5 cylinder engine as far forward as possible, so to make my life easier I decided to remove as much of the front end as I could:

That's a little better. The accessory belts come off by loosening the mounting bolts, and then unscrewing tensioning bolts on the alternator, power steering pump, and AC compressor. Then to get to the timing belt, you just remove the front cover and unscrew the crank pulley. Yup, just unscrew the big bolt holding on the crank pulley:

Uggh. Apparently it's torqued by the factory to over 400 ft-lbs. With that much force, I can't simply put it in gear to hold the crankshaft in place. I might break the transmission. There's a special, hard to find tool meant to hold the crank pulley, but I'm not spending $150 on it. Instead I wedged a prybar against the notch in the crank pulley, and then jumped on my breaker bar to loosen that horrible bolt. With that out, the old timing belt could come off along with the crank sprocket and accessory belt pulley.

I decided to take the extra time and remove the rusty valve cover for repainting. The gasket was starting to leak anyway, so why not? Here's what the camshaft looked like:

 

The camshaft seal was starting to leak, so I replaced it while I was in there:

 Time to clean the oil and grease off the valve cover:

 I used naval jelly to dissolve the surface rust before painting it with black grill paint:

 

With the cover reinstalled, it looks a lot better:

And here is that horrible crank bolt: 

 

A curious thing about the timing belt on this engine - the water pump is the belt tensioner. It has two slotted bolt holes letting you rotate the pump in order to provide tension on the timing belt. It's a very strange arrangement, and the water pump makes a seal against the flat engine block with a large O-ring.

Now with a new water pump and belt installed, I can start reassembling the front of the engine. The timing marks weren't easy to find, so I just put matchmarks on the old belt and transferred them to the new one so the cam and crank will still be lined up. Then I pried against the water pump to tension the belt and tightened the water pump bolts to lock it in place. I also added some sil-glyde to the new water pump O-ring so it could slide across the engine block as needed.

Tightening the crank bolt was a little tricky, but I managed to nail some 2x4's together to brace against my pry bar:

Then I put my foot on my breaker bar and called it tight enough. With the engine back together, all that's missing is the rest of the front end:

Job done, cheers!

Audi 5000 Revival III - Brakes

The brakes on this car need attention. On very old cars, the calipers get corroded around the piston seal and can get stuck in place. This results in a stiff brake pedal that doesn't do very much braking. Replacement calipers are not even available for this car, but new seals are.

Getting the caliper pistons out was tricky. Normally I blast them with air from my compressor, but these wouldn't budge. I had to heat the aluminum part of the caliper on my stove to expand it enough to let the piston pop out.

Now I can clean the seal grooves and the piston with a wire brush. I like to install the new seals with a thin layer of Sil-glyde, which is compatible with brake rubber. This lets the piston slide in without trouble.

The outer dust seals on these VW style calipers are tricky to install. They need to tuck into a groove in the caliper, and they also fit tightly onto the caliper piston. The best way I found to install it was by first sliding the dust seal onto the edge of the piston, then tucking the seal into the groove on the caliper body:

Then with the dust seal fully seated in its groove, you can start pushing the piston into the caliper. If you did it right, the piston should slide in by hand with careful force.

As a finishing touch, I wire wheeled the rust off the cast iron portion and painted it with barbecue black paint:

The other side is the same process. Finally, I reinstalled the calipers with new flexible hoses and brake pads.

The rear drum brakes weren't working so great either. The wheel cylinders are fortunately easy to change, and don't require fully disassembling the brake shoes. Just remove the hold down springs and pull the shoes out of the way:

Now there's two 5mm allen screws and an 11mm brake line nut holding the wheel cylinder on. Good luck if they're rusted. A long time ago I ended up removing the entire brake and stub axle assembly from my brother's '84 Jetta in order to drill out the little screws holding the wheel cylinder in place. You don't need to go that far though. If the 5mm allen screw is stripped, hammer a 12 point 3/8" socket onto the head, or use a 3/8" bolt extractor. The latter option worked perfectly for me. Here's my prize:

Lucas parts are only the highest quality, as evidenced by the fact that one piston was seized in place, and the other one leaked.

The brake lines were another issue. One of the rear lines has two compression fittings on it:

Uggh. It would have been less work for the previous owner to just replace the whole 5' section with a new line. Well, now I get to do it. I ended up buying a pre-flared line because I just couldn't get a good bubble flare with the rental flaring tools. 

Securing the new brake line to the car body was actually rather easy. Since some of the metal retaining tabs had rusted away, I used insulated P-clips and rivets instead. To rivet the clips in place, I drilled holes into the car body:

 

It's important to paint the exposed metal after drilling to prevent corrosion (which is where the black paint smudge is). Next I installed a 3/16" rivet with some added anti-corrosive spray to secure the new line:

This is a much better method than using self-tapping screws. Now what's left is to connect the replacement brake hoses and bleed the system of air.

With new wheel cylinders, caliper seals, brake pads, hoses, and the new hard line, these brakes work a lot better.

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.

Building a Cheap and Cheerful Singlespeed

It's time to build something a little different.  The white Schwinn Traveler that I repainted was in pretty rough shape, and I want to rebuild it without spending a lot of money.  Its front derailleur was the wrong clamp size, and used a rubber shim to secure it to the seat tube.  The rear derailleur was corroded and in bad shape (I think this bike was left outside for years).  Instead of trying to find replacements, let's just do away with them both. 

To make a singlespeed conversion you first need a singlespeed freewheel.  In the past I used inexpensive Dicta freewheels, but new bike parts are getting rather expensive now.  I happen to have an old 5 speed Normandy freewheel with a worn out 14 tooth sprocket.  Using a pair of chain whips I was able to unscrew both the 14 tooth and 17 tooth sprockets from the freewheel body. After sliding off the remaining sprockets, I reassembled this freewheel with three spacers behind the 20 tooth sprocket.  Since this sprocket is splined, I screwed the 17 tooth sprocket back on to hold everything in place:

This setup is a little bit heavier than a proper singlespeed freewheel, but the goal here is cheap.

Next it's time to look at the front part of the drivetrain. After removing the 52 tooth chainring there is an issue with the chainring bolts:

You can buy shorter chainring nuts and bolts to fit a single chainring.  However, that costs money so that's not an option for this build.  Instead I can grind the nuts down to make them shorter.  An even easier option is installing 10mm or 3/8" washers in place of the large chainring.  These washers will take up the slack and allow me to fully tighten the bolts.

I ended up having to grind a flat side on each washer so they could fit properly on the crank spider, but that only took me a few minutes.  With all the washers in place, the chainring could be securely installed:

The chain needed to be shortened, so I loosely installed the rear wheel and looped the chain around both sprockets in order to find the right length. Since this frame has horizontal dropouts, there was a lot of room to adjust the chain length:

Getting the chain to run straight between the front chainring and the rear freewheel is the main concern when you convert a bike to singlespeed.  To accomplish that, I simply moved the 40 tooth chainring back to its original location on the inside of the crank spider.  This provided a nice straight chainline:

After reassembling the rest of the bike I spent a slightly painful amount money on new handlebar tape.  The drivetrain isn't the prettiest, but this bike rides quite nicely.

Repainting a Bike Frame

 I bought a Schwinn Traveler that has seen better days:

At first I sort of liked the dirty rusty paint, it looks like an old messenger bike that has been ridden for thousands of miles.  However, I live in the salt belt so it just reminds me of every old beater car I see on the road.  Time to deal with it.  I used a product called Naval Jelly to dissolve the rust and prevent it from returning:

After brushing it on the entire frame I left it overnight to do its thing.  Next I hammered out the headset cups with a tool I made from a length of metal electrical conduit:

Now it's time for the tedious part.  I sanded the existing paint (or at least whatever is left of it) with sandpaper and a medium grit sanding sponge.  The idea was to blend the chipped edges of the paint into the bare metal so that the edge lines wouldn't show through the new paint.  I also tried to avoid hitting the decals since I wanted to keep them.  After sanding, I cleaned the frame with denatured alcohol:

 Next I taped over decals with masking tape:

I should mention that I am not a professional painter, and I also didn't have the time or motivation to make this paint job look perfect. I just wanted the bike to look presentable from 20 feet away. Anyway, time for primer:

I sprayed three thin primer coats using a can of rustoleum automotive primer.  After that dried I used some string to hang the frame in my garage:

Spray paint cans are difficult to get a good finish with.  They tend to spray too much paint at a time, which causes drips and runs.  Also, the paint coming out of the can is very thin, so you will have to spray lots and lots of very light coats.  Instead I have a small air compressor and an inexpensive spray gun.  I mixed some rustoleum gloss white and almond colored paint together to try to color match the existing paint:

I also added enough mineral spirits to thin the paint.  The proportions were about half white paint, one quarter almond, and one quarter mineral spirits.  I set the compressor's air regulator to 60 psi and got to work:

The spray gun is much more forgiving than spray cans. I was able to lay the paint on pretty thick without worrying about drips.  After a few coats I peeled off the masking tape.  Much to my disappointment the new paint didn't match very well:

I touched up the areas around the decals by hand with a small brush.  The end result is much better looking than the rust.  It's not perfect, but I'm more than happy with it.