Rust hunting advice

[KJs 83CJ7]

So my new CJ has a great body (clean, dent and rust free, good paintjob) on the outside. Pulling up the rubber floor inside looks solid as well - no rust. When I crawl under, it is hard to tell what is rust and what is just....well, I don't know what. I knocked around and nothing flakes off - also see a lot of oil type gunk under a bunch of the drive shaft components.

I guess my question is, what SHOULD the underside of the Jeep look like, and what should be done to clean the underside, prevent rust and repair any problem areas?

Cheers.

 

[Sasquach]

When your CJ left the showroom all sheet metal inside and out was painted the same. So when you crawl under you should see painted metal, chances are you won't but thats what it should be.
How do you protect it? remove the rust, prep and repaint it.
When I did mine the worst rust was under the winsheild seal to tub and behind the hinges, tilt your windsheild forward and look under the rubber seal in concerned.

 

[KJs 83CJ7]

Any advice or instruction on removing? Tools to use/not to use. Also, primer/paint specifics?

 

[Sasquach]

Any advice or instruction on removing? Tools to use/not to use. Also, primer/paint specifics?

I don't see how you could do a decent job without pulling the tub and sounds like yours is not a candidate for that.
How bad is it? Where is it?
Wire brush it and rattle can it for the most basic repair or as I did and pull the body off, take everything to bare metal, respray 2 part epoxy primer and a 2 part epoxy top coat.
I used Jasco paint remover for heavy paint buildup removal, wire wheel on a 4" grinder for light rust, fine 60# sand blasting in hard to get to areas, wire brush, sandpaper or whatever was best for certain areas.

 

[KJs 83CJ7]

Well that is the thing....I guess it's hard to tell what the heck i'm looking at under there. It doesn't look like what I'm used to seeing from soemthing that is all rusted up. I guess I'll have to crawl under and work a wire brush in some areas to see what it actually is..or try to power wash (might just be years of dirt and grease). Please excuse my lack of skill, just starting to bite into this......

 

[Sasquach]

Start with a dgrease.
The CJ I'm working on now owes it's rust free frame and peices to all the oil leaks and grease covering everything in a thick coating.

 

[IOPort51]

I like that!!
"It's not an oil leak, it's long term undercarrage maintainance."

 

[KJs 83CJ7]

Have any of you guys used the Monstaliner? (Monstaliner do-it-yourself roll-on truck bed liner outperforms Herculiner Bed Liner, Duplicolor and Rustoleum Road Warrior). It looks pretty good compared to some of the other guys out there doing it. In the FAQ it says you could spay this on the underside - but I'm thinking I may do this in the tub and get rid of the ugly rubber interior liner i've got...

 

[CJKrawler]

If you can tap on the undercarriage, and you don't get anything but dirt, or it sounds like solid metal, you should be good. Knocking all of the grease and oil off will make it more susceptible to rust. If you are ready to pull the tub, then I would go through it. There are only a few extras braces underneath, most of the tub you can feel from the top(inside of the tub).