Where to spray rear bed bolts from underneath

Before installing some bed stiffeners, I'd like to hit the 4 rear bolts with WD40 or PBblaster.

Wondering if anyone has any suggestions on how/where to spray from underneath (pics would be nice)

I had a quick look just peeking up under the bed, but couldn't really see where.

The tops of my bolts don't show any rust but I'm guessing receiving bolt underneath might be rusted (frame definitely has rust)

My plan is to undo them with a Milwaukee 1/2'' impact once the bolts have been soaking awhile

Wondering if just hitting them from the top with PBblaster would be sufficient...

 

If you look inside the frame channels from underneath you can see where they come through.

 

The little swivel bolt isn’t easy to spray.
You’ll need a good creeping oil to soak in and UP the threads.

The big bolt is easier.
It will be messy, but you can get to more of it.

Swivel mount bolt. It is right at the corner of the bumper. Where the wire harness goes up into the bed.



The big goes down in to the frame

.

 

We both must have been under out trucks at the same time. Lol

 

Those are great pics, super helpful thanks to the both of you!!! Makes me want to be under my truck right now lol. I need to put some old clothes on and crawl under there with the PBblaster can! hopefully it wicks well.

 

Fwiw, I never thought hitting those particular bolts w/ PB or anything helped much. I did realize that coating them with a marine grease did show significantly better corrosion protection compared to anti-seize. In case you were planning to apply something before reinstalling.

 

Interesting. I hit them from the top today, not from underneath yet, need to get suited up to go under there shooting PB above me. Maybe I'll just go for it with the big impact and regret it later . Was thinking about heating them up briefly with a torch right before. Also may order some new bolts and marine grease them.. if I'm successful getting the old ones out

 

I can't say I'd start with an Impact.
And impact is nice. Until it isn't. And that when it goes south QUICK........

I'd start with a big breaker bar and the shortest bit I could find.
I like to "feel" what the bolt is doing. Even more so on torx bolts. If you round it out. It's hell to pay.
I want to feel if it is stripping? Are the threads gumming up with rust?
Sometimes you have to go back and forth, and back and forth. That way you don't strip the threads COMING OUT.
You can't feel anything with an impact. By the time you feel it, it's too late.

 

^^^^This

 

$21 Kroil Original Penetrating Oil with SprayTech 360° Nozzle & Straw (Aerosol Spray-13oz Can-Single) | Every Drop, Every Angle, Even Upside Down | Penetrant for Rusted Bolts, Hinges, Chains (KS132ST)

Aerokroil is but has worked well for me up in New England.

 

I second this^^
And yes, you'd better spray them from the bottom, a few days before you begin trying to loosen them.
If/when you get them to move a little, work them back and forth (counter clockwise/clockwise) a bit. They will likely be a booger and you don't want to strip the Torx head.