88 MJ long bed, frame rot repair

This is more or less exactly the same damage as was repaired on the passenger side several years ago by Bill @ SVE. I literally pulled out about 5-7 pounds of sand, rust, and mouse nest from inside the frame rail. The interesting thing its probably been held together by paint for many many years. Kudos to the New England weather and whatever the original owner did to this thing.

Runs all the way forward to the middle of the door

Back to above the axle

Inside going rear

Inside going forward

Brutal huh? Hats off to boxed frames.

Out of curiosity, how did SVE repair the side that was fixed? And how well has the repair been holding up?

BTW -- good photos.

Ouch...

Out of curiosity, how did SVE repair the side that was fixed? And how well has the repair been holding up?

 

It's been holding great, like new. They fixed it simply by welding in new steel, they didn't overlap or anything just welded straight into the existing frame. I did a lot of the prep work and cut away most of the bad stuff with a grinder and then shaved down the surrounding frame to bare metal. I think all they had to do was shape new steel and weld it in. Then I took it home, threw on some primer and a layer of undercoating. The problem with the driver side is all the fuel and brake lines. And the gas tank may be in the way. (edit: just thought about that further, they can weld inside the frame rail as opposed to doing it from the outside where the gas tank is then box in the rest)

Really what I need to do though is pull off the bed and do the entire thing.

Shot of the passenger side patch from about 3 years ago. Already getting new rust under the undercoating.

This type of rust is exactly why I pulled my truck off the road last November. I suggest pulling the bed, and going over the whole rear frame. The extra access may show u more spots that need attention. CT and Comanches don't seem to have lasting realtionships! Good luck, great pics.

More! :banghead:

first cut on the driver side

And first cut on the passenger side! You can see the SVE fix at the end of the cut. That was done, I think, about 4 years ago.

PS side looking towards the front

PS looking rear

These frames are just canals of steel death.

One minute I'm all gung-ho about fixing it, the next I'm ready to sell it for parts. But for now I want to keep cutting and chisel away inside the rails and see how deep it is.

Got the bed off. Broke 2 of the 8 bed bolts and the gas tank hangers were barely holding those j-bolts in, scary.

Top the frame isn't too bad, a few rusty spots but nothing some Rust Bullet won't cure.

Previous owner sandwiched his custom hitch around the frame rail, well done I think.

Any ideas for cleaning out the frame rails?

Then there's the gas tank. I need to move it to get to that side of the frame. Do I need anything special to remove the fuel pump? What about depressurizing the lines, or is that only when the vehicle is running?

Forgot to add these photos. This is the real trouble spot

The spring hanger is peeling away from the frame. Somehow I need to weld that so at least it's a rolling chassis.

I didnt realize comanches were suseptible to rust in those areas. :eek:

Cut a bunch out this morning after moving the gas tank and took the wire wheel to the top. It's all surface rust up top, the shock mount is solid too.

The pic is worse than it actually is, the spring hanger and the inner frame is still ok. I whacked the hell out of it and it held. Will probably still cut it out but not until the hanger is welded back in place on the outside.

Inside looking forward

SVE patch

Maybe a mod could move this thread to the projects section?

Maybe a mod could move this thread to the projects section?

sure, what would you like as a title?

How about: "88 MJ long bed, frame rot repair". Thanks.

If mine ever gets that bad I think I'd rather just create new frame rails from 3/16" steel, chop off the back section completely, and graft them in right behind the cab.

Small update: Got the two major patches cut and roughed in. The outer needs a bit more shaving on the bottom to match up perfectly with the spring hanger.

Just need a tiny shave on the bottom to flush it up.

I think on this inside patch I'm just going to cut another big piece and go into the shock mount and upper rail versus just filling in that little bit underneath.

Wow... That sure looks like alot of work :eek: . Keep it up. Your project makes me feel bad about when I get frustrated with my rust problems :bowdown: ... I'm anxious to see how it all comes out.

Now that the bed is off are you gonna rust bullet the whole rear frame?

Time consuming for sure, tougher with a crappy job and only 1 day off. Bright side, it's been a cheap project, I got about 8 gallons of "free" gas for my other Jeep when I pulled the gas tank and so far only spent about $25 on cut-off wheels. The steel was leftover from past projects. I'll rent a mig to weld in the patches which will run about $75 for the week. Whatever I can't do after the two major patches will probably go to a shop. But I need to get the spring hanger in to be able to move it.

As for Rust Bullet, I'm leaning towards no. I don't want to take the time to wire wheel off all the paint and there's not that much rust to begin with, it's all surface versus rot. For now, I'm just going to primer and paint it. Getting cold too so I want to get it done before January.

Best I can do for a bird's mouth, bit of triangulation. On the inside, I'm just going vertical because the inner rail is still holding on to the spring hanger and decently solid. Really just reinforcing the inside like SVE did on the passenger side.

And some bright shiny paint! Used some old rattle cans in the garage. Spent only $4 on a can of primer. Rustoleum hammered on the axle.

Took some pics of my patches finally. Ignore the red paint, that's what I had in the cabinet :thumbsup:

Gonna have SVE weld in the e-brake bracket. It's only held it with self taps for now. I'd rather a better fix.

Patch under the pass door. Tight spot so I could only do some tacks and 1 or 2 beads. Have SVE finish it.

Ran out of time with the welder and ran out of wire or I'd have done more. But this is plenty I think to be driveable to the shop and save me some dough.

Still figuring out the fuel pump.

Forgot to mention, in that ebrake bracket pic, you can see I cut out the original gas tank hanger mounts for the j-bolts. There were not going to work again so I drilled through the bed and I'll be dropping down carriage bolts.

Got it back on its feet.

New gas tank mounts. Had to chop out the j-bolt hangers.

My part is done. The rest of the frame will be fixed by a shop.

great photos, thanks for posting them. my 88 had been a squirrel hotel too but not as bad as yours. i'll add those photos soon. just the bottom of a few places on the drivers side rail for me, not the whole rail. good luck..