72 Jimmy rust repairs

[87Skier]

Hello everyone,

I'm getting ready to repair the floor and rockers of my 72 Jimmy. So far I think I'll need:

• Outer rocker panels
• Outer cab floor (about 4" in from face)
• Inner rocker panel
• Rocker boxes
• Front cab supports
• A pillar lower sections (about 12" up)
• Kick panels
• Lower bed section (just behind doors)

There are some small issues further in on the floor but it will be much cheaper to make the repair sections myself instead of buying the whole floor.

As far as I can tell, the rear rocker box closing panels look ok. They will be removed, cleaned, inspected, repainted and reinstalled. Do these usually need to be replaced?

Here is some pictures of the floor and underside of the body: Google drive

Anything else I should know? Am I missing any parts in the list?

Thanks!

[Dan_P]

I just did something similar.

Also needed:
- B Pillar lower sections too
- internal rocker reinforcement assembly plate
- front fender lower reinforcing mounting plate

I used GMCPauls. A little more expensive but I wanted to cry once and pay for the 16ga steel. https://gmcpauls.com/Patch_Panels.htm

[best view]

Rust what rust we call that brand new out here lol

[87Skier]

Originally Posted by best view

Rust what rust we call that brand new out here lol

Haha, I can't imagine the nightmares you guys deal with.

Also needed:
- B Pillar lower sections too
- internal rocker reinforcement assembly plate
- front fender lower reinforcing mounting plate

I'm hoping I don't need to get into the B pillar at all. Probably just replace the fender mounting plate, it's cheap enough and in a common rust area. I think the inner rocker is included in the set from GMCpauls. I am going to order from there. Probably around $700 before shipping.

I'm really looking forward to having carpet in it. I've had it since 2013 and it's never had carpet or sill plates.

How long did it end up taking you to do both sides?

[best view]

Mine came from Monterey cal needed both a and b pillars inner and outer rockers bottom of doors and rocker boxes both sides

[jaros44sr]

Are your tetanus shots up to date? What kind of tools do you have? Take lots of pics for reference on reassembly...

[87Skier]

I ordered all the steel from GMCpauls except for the radio patch panel. Also picked up new body mounts. Took a few days to get the new mounts in and had to remove the radiator and rear bumper to install them. Needed about 3/8" under the main support to get the doors opening and closing properly. Then I just filled with spacers going back where necessary to level it out. It feels a lot more solid than it ever has, but there is some noticable rattles and vibration from the engine. I'm thinking they'll wear in a bit more and loosen up. I'll probably end up adjusting the exhaust mounts. They were a bit snug when they went in do that's not doing be any favors.

I'm still trying to figure out what I want to do underneath. I picked up some epoxy primer but I don't know if I want to do undercoat, bed liner, paint or something else to finish it. I drive on a lot of gravel so I can't imagine a paint holding up well, but the thicker coatings can crack and allow water inside.

[87Skier]

Thought I would post an update...

Nearly done with drivers side. I've got the outer floor, inner rocker, hinge pillar, cab reinforcement, door striker pillar, B pillar, driver door repaired. It needed a new lower hinge, but I was able to rebuild the upper hinge. I made alignment marks and took careful measurements so that I was sure all the important points were in exactly the same spot. Everything is lining up very well.

I found some rust in the b pillar and where the door pillar meets the inner rocker. They were paper thin in spots, but still intact. To remove the vertical reinforcement for the B pillar, rocker box, and rocker end cap, I cut a hole inside my Jimmy near the door striker so I could fix the striker nut plate and get at the plate bolted through the floor since they are bolted in from the top. One bolt sheared off and one nut broke it's welds so it had to grind them out anyway. I drilled out the holes to 3/8" and welded two bolts through a plate and installed it from the top. Now I can install nuts from below, Incase it ever needs to removed again.

I test fit the rocker box and everything lines up. It is difficult to get to fit for the first time. Also it can't be sitting on the main cab mount, so I used another jack to hold it slightly forward if the mount. I used a rachet strap to pull it into place once I hooked the front lip onto lip that joins the firewall and floor. This set it very well and made a fight join between the panels.

I'm nearly done with the firewall. I welded up around 15 holes. I'm keeping my heater, so that all got left alone, but i got rid of the wiper washer hoses inside, in favor of an electric one near the bottle. I closed up the, clutch, tail wiring harness, throttle pedal, oil pressure and the firewall mat retainer holes. I still have the brake master, speedometer, parking brake, steering column openings. All electrical connections, except the high current stuff go through a new Deutsche 50 pin bulkhead connector. I'm working on an interior wiring harness with a modem fuse box. It's loo king very clean.

I'll post some pictures soon.

[72gmguy]

Sounds like you got a lot done. What did you end up doing for a finish?

[best view]

My fabrication guru talked me into doing the whole floor, from gmc pauls said that it would save me 2000.00 in labor than doing all the patching and just bolt up all the new rocker box stuff so that’s what I did

[87Skier]

Originally Posted by best view

My fabrication guru talked me into doing the whole floor, from gmc pauls said that it would save me 2000.00 in labor than doing all the patching and just bolt up all the new rocker box stuff so thatÂ’s what I did

Can't argue with saving $2000! I'm not sure I would have had the space to do the whole floor replacement at once, but it sure cuts down the amount of welding and grinding that needs to be done.

Originally Posted by 72gmguy

Sounds like you got a lot done. What did you end up doing for a finish?

Haven't decided on the underside finish yet. I'm leaning towards just epoxy paint. I'm definitely going to spray the inside of the b pillar, rocker panels, rocker boxes and everywhere I can inside panels with cavity wax. Only looked at Creep N' Crawl from Woolwax so far.

[87Skier]

I've got the rocker panel spot welded in place and door back on for the tenth time to check alignment and set the final door gap as I weld the rocker to floor underneath. I need to tidy up the panels underneath to match and behind the door is a bit wavy. You'd have to lay on the ground to see it, but no reason not to make it right.

The door gap is good. Need to adjust it all a little bit, but it's already very close.