Bronco II rear sill fix?

[rusty ol ranger]

86 Bronco II.

Some might remember the rust issues i mentioned in my other thread....but for convience ill rehash a bit here.

The frame and everything is very solid. Its just the rear sill (where the very rear body mounts bolt to) that is rotted. Initially i thought it was the the drivers corner but today after looking its actually rusted worse. The passenger side corner is iffy, and its rotted around the rubber bushings. It is solid throughout the middle though, or atleast from what i can see without removing the fuel tank.

The whole ass end has sagged a bit because of it.

The way i see it i have a few options....wanted to see what you guys thought....in order from most feasable given my body work abilty to least...

1- Undo body mounts...remove rubbers, jack up ass end, try to slide a piece of channel around the sill (so the stock sill sits inside the C channel) across the whole width from tail light to tail light. Drill holes for the body bolts, slide the rubber back in (or replace, they look good though) and bolster up the corners from there.

2- Try to do similar to above....but just use a big thick piece of plate steel the whole width between the body mounts and factory sill.

3- Find a good B2 in a junkyard (asking alot around the rust belt) and attempt to cut out the sill and reinstall in my rig. Theres a guy on youtube who did this but used a 90-94 Explorer sill, he had to narrow it though...and im not sure i can do this myself.

Other POSSIBLE (maybe) options that im curious about....

1- Adapt a sill from another vehicle of similar size (i was thinking maybe an early bronco or wrangler....both of these are available everywhere online for 150 bucks or so)

2- Buy a sill for a FSB (available online), and try narrowing it....but thats a 350-400 dollar gamble.

3- Use the back end of a 1st/2nd gen ranger bed? This one im curious the most about. If i cut it up to where the ridges in the bed floor start, and weld a piece of plate on the bottom to box it in....do you guys think this maybe a feasable option?

I really wanna save this thing. I could probably drive it as is but im afraid of it getting worse to where itd need much more work...and the rest of the body is pretty solid. But im pretty ignorant when it comes to metal and body work.

Maybe im overthinking the whole thing?

Either way....discuss and throw out ideas...im all ears

 

[tw205]

I had this issue with my 89. I bought some sheet steel and made my own beam. When i drilled the holes thru for the mount bolts I over sized the holes and welded a piece of pipe in as a sleeve to prevent the bolts from crushing the tube. Worked well.

 

[RobbieD]

Sounds to me the C channel would work fine, but assumimg that you're missing original metal around the body-to-frame bolts' area, I'm having trouble visualizing how you're gonna tie (attach?) the body in the repair. Weld in and drill some sheet in those areas?

Some pics would sure help us bums in the bleachers.

 

[rusty ol ranger]

Sounds to me the C channel would work fine, but assumimg that you're missing original metal around the body-to-frame bolts' area, I'm having trouble visualizing how you're gonna tie (attach?) the body in the repair. Weld in and drill some sheet in those areas?

Some pics would sure help us bums in the bleachers.

The top of the sill where the bolts go thru is solid. Its the bottom thats rotting. The upright parts of it look and feel solid as well except for the corners.

I figured id slide the c channel under the sill where its rotted with the open side up. Use the stock holes from the top and drill new through the C channel to bolster the bottom and use the body bolts to torque it all togther. So it kinda makes a square

 

[rusty ol ranger]

I had this issue with my 89. I bought some sheet steel and made my own beam. When i drilled the holes thru for the mount bolts I over sized the holes and welded a piece of pipe in as a sleeve to prevent the bolts from crushing the tube. Worked well.

Noted and added to the idea board

I guess my thing is how stout does that piece need to be? I always shoot for nukeproof and overkill when i dont know....but maybe im worrying to muvh

 

[RobbieD]

The top of the sill where the bolts go thru is solid. Its the bottom thats rotting. The upright parts of it look and feel solid as well except for the corners.

I figured id slide the c channel under the sill where its rotted with the open side up. Use the stock holes from the top and drill new through the C channel to bolster the bottom and use the body bolts to torque it all togther. So it kinda makes a square

Got it. That makes the c channel sounds like a plan, with spacers like @tw205 suggests.

I always shoot for nukeproof and overkill when i dont know....

"Design it like it's a cockroach", eh? Never hurts.

 

[rusty ol ranger]

I had another brainstorming session and had a another idea to run by you guys...

Once i get the body up in the air...just cut out the whole bottom section of the sill box....slide a piece of rectangle tubing under the other 3 sides....weld (or have someone weld) it to the tubing...drill holes...insert rubber....done.

Thoughts?

 

[Roert42]

I would make my own parts out of sheetmetal. Essentially just recreate what was there originally with new metal, or close enough. With design adjustments on the fly to make assembly easier.
Something with a hard straight edge and a ball peen hammer, you got a sheet metal brake.

16ga would be my choice, stout enough to hold up, but easy enough to work with a hammer into the shape you need.
I wouldn’t really want to go over 10 or 12ga, unnecessarily thick and harder to work with

You could probably get away with putting everything together with pop rivets.
Welding would probably be easier/ faster, but this probably isn’t the best first project.

I would avoid zip screws since they can work loose. Bolts with Nylocks would work, but it would 1000x more work and expense compared to pop rivets.

 

[rusty ol ranger]

I would make my own parts out of sheetmetal. Essentially just recreate what was there originally with new metal, or close enough. With design adjustments on the fly to make assembly easier.
Something with a hard straight edge and a ball peen hammer, you got a sheet metal brake.

16ga would be my choice, stout enough to hold up, but easy enough to work with a hammer into the shape you need.
I wouldn’t really want to go over 10 or 12ga, unnecessarily thick and harder to work with

You could probably get away with putting everything together with pop rivets.
Welding would probably be easier/ faster, but this probably isn’t the best first project.

I would avoid zip screws since they can work loose. Bolts with Nylocks would work, but it would 1000x more work and expense compared to pop rivets.

You think pop rivets would hold?

I found some pretty thin rectangle tubing. I guess maybe im underestimating strength of things.

I thought about trying some of that 3M impact adhesive that bodyshops use for structural repair.

Its just one of those things i dont have a clear direction on so im obessing over it.

 

[RobbieD]

I thought about trying some of that 3M impact adhesive that bodyshops use for structural repair.

Recommended and endorsed by Bubba's Bodyshop and Bar.

Accept no substitutes!

 

[Roert42]

They hold airplanes and bridges together with rivets. You’ll be fine. I’d probably put them every inch and half.

I would lay out the panels and drill a couple holes, apply automotive seam sealer, install the panel, then drill the rest of the holes and rivet them.

 

[rusty ol ranger]

Well i can quit freting now.

Talked to our mechanic at work, he builds and races late models, so hes probably pretty good at fab and welding. He said if i load it up and bring it to his place he'd onli charge me a couple hundred to fix it.

now i can quit bugging you guys lol.

 

[RobbieD]

Well i can quit freting now.

Talked to our mechanic at work, he builds and races late models, so hes probably pretty good at fab and welding. He said if i load it up and bring it to his place he'd onli charge me a couple hundred to fix it.

now i can quit bugging you guys lol.

Well, that's just great . . .

While you can quit fretting, all of our sense of usefullness gets shot down in flames.

Thanks, pal . . .


Seriously, that's a good turn. As much as I prefer and like doing my own work, it would well worth it to me to farm that job out to somebody with the experience, and that's trusted. And getting a break on the cost to boot. It's a good move, and it's money well spent!

 

[rusty ol ranger]

Well, that's just great . . .

While you can quit fretting, all of our sense of usefullness gets shot down in flames.

Thanks, pal . . .


Seriously, that's a good turn. As much as I prefer and like doing my own work, it would well worth it to me to farm that job out to somebody with the experience, and that's trusted. And getting a break on the cost to boot. It's a good move, and it's money well spent!

I agree. I mean even if he dings me for 500 (which, i doubt) im still in this thing, including purchase, less then 2000. All it needs after the rust repair and FPR is the O2 changed, possibly a turn signal switch, a bit of wiring and wheel cylinders (hoses/lines are all new).

This is assuming the trans/transfer case is good. Fingers crossed...lol. It does have a mitsu trans.

If its junk i think ill swap in a TK5. Yes not as good as a M5OD but ive never had an issue with a TK, it bolts in, and buys a lower 1st gear lol.

 

[RobbieD]

You,ve got a good plan.

These old B2s are not getting any cheaper; if you get it even halfway decent it'll be worth more than you have in it. Maybe a lot more.

The fun of driving it is a bonus on top of that.