Cutlass Rear Axle Restoration

After restoring and painting the rear undercarriage and frame, it became apparent that the rear axle desperately needed the same love and care. It is original to the car and probably worth saving based on that merit.

Before Pictures

Here are the before pictures

Scope

Pretty straight forward job. I decided to keep the axle installed for the job, although removing would have obviously been more convenient. The control arms, exhaust, gas tank and frame would simply be taped or covered up to limit overspray. I decided that this was easier than removing the whole axle. Maybe it was, maybe not. The wheels were removed, as well as the brake drums. See our article on our brake drum restoration HERE.

I opted to also upgrade the rear axle pumpkin cover. The stock cover was in fine shape, although lacked interest and I really wanted to have a drain plug for fluid changes. The stock rear cover was kept in place for painting to limit oil mess and overspray into the axle, and then the new cover was installed after the paint cured. On this 10-bolt, the HD cover will add a little strength too.

This is also a great opportunity to upgrade your swaybar, or add a swaybar. The swaybar should be removed before painting, unless you don’t mind getting paint on it. I opted to install a stock style repro rear swaybar during this process.

Prep

The axle was largely cleaned due to an earlier restoration effort (LINK) to paint the rear undercarriage, frame and fuel tank areas. However, especially near the original fill plug and pumpkin areas, years of mud, rust and grease were at least 1/2″ thick. I scraped off the bulk of the grease with a trowel, and then used industrial strength degreaser to remove the rest of the grease. The scrubbing took a great deal of elbow grease and about 4 hours, but the results were good. Some of the grease was so old it simply wasn’t affected by any kind of soap, so I broke out some gasoline and a brush which worked very well. After the gasoline cleaning of the trouble areas I wire brushed the entire axle, trying to remove as much loose rust as possible. The areas where the wire wheel couldn’t reach were done by hand with a small wire brush. A final soap and water wash followed by drying finished up the prep.

Paint

For the Axle, I decided to go full gloss black, and I’m very happy with the choice. The primer selected was Automotive Primer for rusty applications (Self Etching, although it didn’t say that on the can).

I primed the entire area to be painted black. Again, I made sure the primer was a different color than the paint so I could see missed areas. One coat of primer was applied.

The painting went very quickly and easily. Three total coats of gloss black Automotive Enamel were applied. The results look great, and I wish I’d done it sooner! AGAIN though, I’ve decided to put all of my work into an area almost nobody will see! I need to work on some more visible areas at some point…

After painting, the Moser cover we went with was installed. Quick and easy install and took about 20 minutes. Moser shorted us one of the 10 required bolts, so it delayed final torquing until the next day. Very disappointed in Moser for that careless omission. 80w90 gear oil was added afterwords (you’ll need a little under 2 quarts for a 10 bolt). Since the cover was off we also inspected the gears, axle internals and drum brakes, and everything looked good.