Replacing a rocker panel

[whtbronco]

My passenger side rocker panel rusted out. I intended to replace it October 2023, but it got put off due to an accident and vibration issues. Now it's finally back to the top of the list. I got started today and found what appears to be a support bracket that goes from the B pillar to the rocker panel. It was a fairly thick piece of U shaped sheet metal, compared to the exterior sheet metal at least. Well it's completed rusted through, heck a good portion of it is completely gone. The question is do I need to rebuild/replace that, it just doesn't seem like it's very important since it clearly has not been connected for a couple years. In fact this bracket allowed dirt to build up inside the rocker causing all the rust. Had I known that was inside rocker panel I'd have washed it out better and will in the future. Kinda sucks that I do actually wash out the rocker panels a couple times a year, but with all the dirt there I didn't do enough.

If I do replace it I can weld it up top before I put the new rocker panel on. I think I'd have to drill holes in the rocker panel to weld the bracket/brace to the rocker.

 

[BigOleFordFan]

A common problem, with several other posts here.

Best solution is to get some replacements and weld everything back together underneath, to make sure everything is nice & solid. Most of the replacement panels can be welded into place, or at the very least, screwed down with stainless steel, self-drilling screws or rivets... just be sure you get the right ones for your model

For example:

2004 Ford Expedition Repair Parts | Mill Supply, Inc.

Explore our auto body panels. Our restoration panels fit all makes and models, such as Chevrolet, GMC, Dodge, Ford, Honda, Toyota, Volkswagen, and more!

www.millsupply.com

or maybe check ebay

 

[whtbronco]

Thanks. I don't think I have seen Mill Supply previously so I have added that to my supply list. Next year I plan to do the driver side rocker panel and I don't have that panel yet.

I have the passenger side rocker panel, been sitting in the garage for more than year. Just wondering about the brace behind it that runs 4-5" up the B pillar. Over night I pretty much decided to take 2 layers of 18ga sheet metal and make a replacement for the bracket. Though I'm not convinced it's needed.

 

[BigOleFordFan]

Though I'm not convinced it's needed.

"the higher, the fewer" -Alexander Rozhenko

 

[whtbronco]

Well 2 days in and I have eliminated the rust and primed everything. The inner rocker had just a little spotty surface rust, the rocker at the C pillar had no rust surprisingly. It's really just a portion of the rocker panel and the B pillar brace.

Tomorrow it's time to fabricate a replacement for the B pillar to rocker panel support brace and start putting it back together.

An air hammer makes spot welds almost nothing to separate.

 

[whtbronco]

After day 4 I have everything welded in. Just a couple spot welds underneath to remain to get to and 2 butt joints that are only about 1/3 welded. Then time for a bit of body filler and paint.

Things I've learned during this process.

It's easier to burn through the sheet metal than to weld it, haha. Yep I am not a very experienced welder so I have burned 5 or 6 spots. I also filled those spots back in.

Cavity wax never dries and it's kinda nasty stuff, but it should help delay the return of rocker panel rust. Funny thing it says 2-3 coats will generally provide good coverage. Okay when do you recoat since it doesn't dry, I dunno.

Weld through primer is awesome.

Bending and cutting sheet metal without a brake is time consuming. I've gotten way to friendly with my angle grinder. We probably should have some sort of hearing protection for extended angle grinder use.

Make sure the angle grinder has completely stopped before setting it on bare skin, or you'll get some road rash.

Do not hit bald head on cut sheet metal, it's makes red stuff come out of you. I did it twice, ugh.

I still hate laying on my back and welding over myself. No significant burns today though.

 

[whtbronco]

It took me 8 days to complete the rocker panel replacement. My days varied between 2.5-6hrs with the exception of paint day which was 8.5hrs.

I used 3M Cavity Wax inside the rocker panel as recommended by 2 trusted body techs. I noticed it pretty much plugged up the built-in drains. I cleaned them out with strips of paper towel, at least I think I cleaned them out. When you spray this stuff on it kinda looks like spoiled cottage cheese. After a few days it thins out dramatically So anyway, if you choose to use cavity wax beware it may plug the drains.

Getting the doors realigned correctly was quite challenging. Doing so by myself proved impossible.

While doing this I found the driver side rocker now has a few bubbles of rust and a body mount that is dry rotted and cracked. I thought it was interesting since the others are all in decent shape. So I have a few more tasks to be addressed before long.

 

[whtbronco]

So one more update for this thread since it's interesting to me. I had a squeak caused by the 2nd row center and passenger side seats rubbing together. This lasted for more than a year. I could not get it to stop unless I rolled the passenger side seat forward. After repairing the panel there's not been a single instance of the squeak. I have tried adjusting the seats both fore/aft and side to side, but it won't squeak.

I suspect that the B-pillar to rocker panel bracket being rusted away and fairly sizable rust holes in the rocker that the floor pan may have been flexing. I can also say without a doubt that the repair resolved the soft feel of the running board. So I guess the rocker panels really are a structural part of the body.