Rear Subframe Rotted!
 

Bit of history here. When we bought our X5 I knew it had a little bit of rust here and there, but the body is straight and very clean. I'm in Florida, so that's par for the course. I didn't know how bad it really was.

When a front CV axle started clicking I found the front subframe had a bit of rot under the sway bar mount. It wasn't visible until I removed the sway bar bushing. That was due to a CV axle clip that seized 1/2 inch from being fully installed in the diff. Wouldn't go all the way in, and wouldn't come back out. There's a whole other thread on that one! Long story short, the entire front end came out and the front diff had to be disassembled... Good times.

I performed a fairly through inspection of the front and rear subframes, determined the rear to be in decent shape compared to the front. I acquired both front and rear subframes at that time but only swapped out the front. It's a big job, especially since the motor mounts, control arms, sway bars, etc., all have to be replaced too.

Fast forward to last week. Rear brake pad warning light came on. When I pulled the left rear wheel there was a huge crack in the frame staring me in the face! Probably a week prior I felt a pop from the rear when pulling up the driveway. I honestly thought I'd run over something. There was a palm frond down in the driveway after some massive winds we had. Guessing now it wasn't a frond...

Took a bit of work to get this beast out! The exhaust and diff were the worst to remove with rusted bolts fighting me every step of the way. You can see with it out how bad it really was. Wish I had more photos of it before it was removed. It really didn't look that bad when it was installed. I can't believe it drove without any issues!!! At red lights I had a slight vibration, but it seems everyone complains about that so I didn't pay it much attention. After seeing the condition of the bushings, I'd say I found the culprit.

I've got new bushings in the new frame and it looks like I have some control arms and bolts to order. Guess I'll be driving my Corvette as a daily for little while!

That's horrific.

Right! I honestly felt like throwing up when I thought about my daughter driving it recently... At least I'm good with a wrench. This would have totaled it otherwise.

Wowsers. This been a FL car all of its life? That looks like a northern car's under carriage. Did you coat the new subframe in anything before install?

It was definitely a northern car. My buddy is an ASC Cert. mechanic from Michigan. He was stunned, but said his northern Jeep looks just like mine underneath. Both the frames I bought are used, but like brand new. Shouldn't have any issues in the future, especially since I'm not one for driving on the beach. We leave that for dumb ass tourists to do that think it's cool. LOL

For my Northern rides I use

https://www.por15.com

liberally on all exposed undercarriage components and that stopped rust dead in its tracks.

It can even be applied over existing rusty components but a superior result can be had with their Metal Prep

https://www.por15.com/POR-15-Metal-Prep_p_15.html

This kind of horrific rust doesn't have to happen to our machines. :thumbup:

Mike

Has anyone used the electronic anti rust system? I'm just asking since I obviously don't have to worry about rust over here...:stickpoke:

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