Over the last couple of afternoons I’ve been working on getting the underside of the chassis prepared for paint. I’ll still need to pull the engine & transmission before finishing up some of the areas closer to the engine bay, and the inside of the transmission tunnel, but the goal was to get everything painted right up to the engine firewall.
Overall there wasn’t a ton of rust on the underside of the chassis. Mostly just surface rust that came off with a little bit of sanding and a wire brush. But there were a couple of trouble areas right around where the lower rear trailing arms connected to the chassis. But an hour and half with the grinder managed to get them down to bare metal. My shoulders are feeling that work today!
One area that I’ll have to address is building some small heat shields to go in front of the extra afterburner speakers. They’re pretty close to the exhaust pipes, but I’ll create some steel shields and cover them with some reflective heat material. I’ll also heat wrap the exhaust pipes in front of this area for extra heat protection.
Before sanding down and getting everything sprayed with primer I needed to disassemble the rear suspension and remove the axle, air bags and trailing arms. That left me with a nice pile of parts that needed to go to the media blasters. I’ll be picking them up today and they should be nice and baby smooth without any rust! I also picked up all of the parts that I need to change out the gear oil, replace the diff cover, replace the pinion seal, and all new brake replacement parts for the rear.
I still need to track down some new bushings for the cracked ones which you can see on the top of the differential that are for the upper trailing arms. I haven’t been able to find any aftermarket stock replacements yet, so I might have to give GM a call.
Once everything was out of the way I was able to finish up some welds on the exhaust hangers to make sure they were good and strong and then I spent about a full day sanding, grinding and cleaning everything on the bottom of the chassis. All that was left to do was to spray everything with a nice coat of primer/sealer. Here you can see a nice before and after shot.
I’m also glad that there wasn’t a ton of rust under the bottom of the floor pans beneath the seats. This area is a little closer to the ground and is a little more awkward to get some “umpf” into your sanding. But it’s now all nicely primed and sealed.
Today I’ll be first seam sealing all of the areas where there are joints/gaps where steel meets steel which can allow water to get into the gaps. This paintable joint sealer sets up and can be painted in about 30 min. So as soon as I’m finished sealing the entire underside of the car I can pretty much begin back where I started to paint.
I also picked up the brand new driveshaft yesterday. The old one was one filthy, nasty, rusty mess. I don’t want any kind of driveshaft failure on the car so this new 3″ driveshaft was built to match the length/specs of the original.
If I can get my hands on some new bushings for that rear axle, I should be able to re-assemble the rear suspension at the beginning of next week. Then I’ll be starting on the front part of the chassis to give it the same suspension tear down, surface rust removal and then prime and paint 🙂