Body mount bolts

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

PrairieDrifter

Full Access Member
Joined
Dec 28, 2014
Posts
3,488
Reaction score
4,663
Location
North Dakota
First Name
Mason
Truck Year
84,79,77,70,48
Truck Model
Suburban k10, bonanza k10, c30 C&C, c10, gmc 1/2ton
Engine Size
350, 350, 350, 350, 350
Ok guys, I got my suspension lift in and i've been working on the body lift. I got all of the bolts broke loose except for two(4 actually) the two in the rear should come off just fine they're just in a crappy spot.

The two I have problems with are right behind the firewall, i figured if i had problems i could just access the nut right above it, so i pulled the carpet back and wouldn't you know, there are no nuts there. I'm guessing they are inside that floor pan support. The nuts aren't spinning, its just ridiculously hard to turn the bolts even with a big ass breaker bar, and that's quite a bit of bolt to turn out and i'm getting tired of it haha. One question i have is how are they mounted in there? Are they just tack welded to the body or do they have some kind of special nut?

I'd like to cut it out or something, other than continuing to wear myself out every time i touch it and get more and more frustrated... I've been soaking the crap out of it with pb blaster.

Any tips or tricks on those two? If not ill just keeping prying on the damn things:lazer:
 
Last edited:

bucket

Super Moderator
Staff member
Super Moderator
Joined
Aug 3, 2010
Posts
29,230
Reaction score
24,394
Location
Usually not in Ohio
First Name
Andy
Truck Year
'77, '78, '79, '84, '88
Truck Model
K5 thru K30
Engine Size
350-454
They are captured square nuts inside the floor support. Usually the bolts either simply come out or the square nuts spin in their cages. Maybe you are lucky and the bolts are just over-torqued. Put a longer bar on it, or a cheater pipe on the bar... they will either break loose, break off, or spin the nuts.
 

PrairieDrifter

Full Access Member
Joined
Dec 28, 2014
Posts
3,488
Reaction score
4,663
Location
North Dakota
First Name
Mason
Truck Year
84,79,77,70,48
Truck Model
Suburban k10, bonanza k10, c30 C&C, c10, gmc 1/2ton
Engine Size
350, 350, 350, 350, 350
That's what I figured. What the hell am I supposed to do if the nut starts spinning? Cut a notch out of the floor support? They're not over torqued because I got them to break free but then after a turn or so it gets just as tight as it was when I first broke them free, so they're just really rusty.
 

Don5

Full Access Member
Joined
Oct 5, 2014
Posts
1,136
Reaction score
72
Location
West Virginia
First Name
Don
Truck Year
1979
Truck Model
k15
Engine Size
350
MY 2 Cents FWIW. I would use a round metal cutting hole saw bit and cut down through the floor. Once through the floor I would either weld the nut to keep it from spinning or put a wrench on it. I would weld the nut though before buttoning up the hole. I would weld the cut piece of the floor back into the floor. Cover with vinyl or carpet never to be seen again.
 

PrairieDrifter

Full Access Member
Joined
Dec 28, 2014
Posts
3,488
Reaction score
4,663
Location
North Dakota
First Name
Mason
Truck Year
84,79,77,70,48
Truck Model
Suburban k10, bonanza k10, c30 C&C, c10, gmc 1/2ton
Engine Size
350, 350, 350, 350, 350
Punching a hole through the top sounds like a way better idea than going through the side of the floor support. That might make the removal easier for me too..

I'm positive the nuts aren't spinning, I can put all of my force on it and it will break free slightly, until it gets as tight as it was and I have to get another bite on it. Its just really rusted together. Now lets see if I can get right on top of the nut when I drill the hole:rofl:
 

Greybeard

Full Access Member
Joined
Jun 7, 2014
Posts
91
Reaction score
3
Location
Iowa-under a rock
First Name
Randy
Truck Year
75 something (maybe ???)
Truck Model
k10 and a 1/3
Engine Size
355
I work on a lot of old farming implements that have sat outside for decades and have stumbled on a few tricks and some commonly known ones that I never learned. For starters never try to keep removing a bolt after it starts to seize once you have broken it loose, all it will do is seize tighter. Tighten it back down, if it frees up while doing this you haven't stripped the threads yet. Then muster all of your patience and your neighbors too, it's gonna be a long boring process from here. Douching it with PB isn't doing anything from the bottom but making a dark brown or black smelly mess. As you said, it has rust on the exposed threads on top and inside the support. The solution is obvious as long as the bolt freed up when it is re-tightened. If it did not, break out the hole saw or hot wrench. If it did, turn it out until it resists, force it a smidgen more (about half a flat) and then turn it back in all the way, repeat ad nauseum until it comes out which it will eventually as long as the bolt does not break (a body mount bolt is unlikely to break easily). What you are doing is cutting the rust off the exposed part of the threads, hopefully without rounding off or flattening the threads on the bolt or inside the nut. This is best done with a smallish air or electric impact because it can take awhile. It does take patience however. I've spent over half an hour removing one bolt doing it this way but the bolt ended up being reusable. Factory bolts and nuts are generally very high quality fasteners. They cannot afford the liability of anything less, even if the components they are holding together are made out of aluminum foil. They can argue a case about component failure, not so easy about a fastener failure.
 
Last edited:

Georgeb

Full Access Member
Joined
Apr 30, 2015
Posts
3,259
Reaction score
214
Location
Wisconsin
First Name
George
Truck Year
2003
Truck Model
K10 Burb Z71
Engine Size
5.3
I work on a lot of old farming implements that have sat outside for decades and have stumbled on a few tricks and some commonly known ones that I never learned. For starters never try to keep removing a bolt after it starts to seize once you have broken it loose, all it will do is seize tighter. Tighten it back down, if it frees up while doing this you haven't stripped the threads yet. Then muster all of your patience and your neighbors too, it's gonna be a long boring process from here. Douching it with PB isn't doing anything from the bottom but making a dark brown or black smelly mess. As you said, it has rust on the exposed threads on top and inside the support. The solution is obvious as long as the bolt freed up when it is re-tightened. If it did not, break out the hole saw or hot wrench. If it did, turn it out until it resists, force it a smidgen more (about half a flat) and then turn it back in all the way, repeat ad nauseum until it comes out which it will eventually as long as the bolt does not break (a body mount bolt is unlikely to break easily). What you are doing is cutting the rust off the exposed part of the threads, hopefully without rounding off or flattening the threads on the bolt or inside the nut. This is best done with a smallish air or electric impact because it can take awhile. It does take patience however. I've spent over half an hour removing one bolt doing it this way but the bolt ended up being reusable. Factory bolts and nuts are generally very high quality fasteners. They cannot afford the liability of anything less, even if the components they are holding together are made out of aluminum foil. They can argue a case about component failure, not so easy about a fastener failure.

You cam also bend up an arisol can straw so you can stick it up in where the nut is and get the Penitrating oils on the threads where you need it. This does work but it does take a lot of patience.
 

PrairieDrifter

Full Access Member
Joined
Dec 28, 2014
Posts
3,488
Reaction score
4,663
Location
North Dakota
First Name
Mason
Truck Year
84,79,77,70,48
Truck Model
Suburban k10, bonanza k10, c30 C&C, c10, gmc 1/2ton
Engine Size
350, 350, 350, 350, 350
There are two drainage holes on the bottom of the support so I was able to get a good amount of pb blaster in there on the threads. Trust me ive dealt with plenty of rusty bolts.. I did walk it back and forth to try and break it free, my impact wouldn't do it, and I definitely wasn't gonna use a torch lol.

Its funny you mentioned that they use high quality bolts, the one I was having problems with finally snapped off in the center due to the diameter being half the size of the original bolt, from being rusted away. Five of the 10 bolts I removed were about as rusty but not as bad and the body mount bushings were all corroded and rusting away.

So now I have half a bolt stuck in the hole, I think im gonna drill the center of the bolt out and get a little western with it. I did end up cutting a hole through the floor, since 4 inches or so is hanging from the bottom of the cab ill drill it out from the top, then ill collapse it, and probably just use a vice grips and wiggle it out.

That's what I get for living up north haha
 

Greybeard

Full Access Member
Joined
Jun 7, 2014
Posts
91
Reaction score
3
Location
Iowa-under a rock
First Name
Randy
Truck Year
75 something (maybe ???)
Truck Model
k10 and a 1/3
Engine Size
355
I live in Iowa, no good comes off the salty winter roads.

Wondering though, what delirium caused you to want a body lift?
 
Last edited:

PrairieDrifter

Full Access Member
Joined
Dec 28, 2014
Posts
3,488
Reaction score
4,663
Location
North Dakota
First Name
Mason
Truck Year
84,79,77,70,48
Truck Model
Suburban k10, bonanza k10, c30 C&C, c10, gmc 1/2ton
Engine Size
350, 350, 350, 350, 350
I live in Iowa, no good comes off the salty winter roads.

Wondering though, what delirium caused you to want a body lift?

Driveline angles mostly, anything bigger than a 4 inch suspension lift gives you horrible driveshaft angles and everything wears out quicker IMO.

What cons are there to body lifts? The body is riding on body bushings with a flat steel plate on top originally. So what's the difference when the body is just up a little higher off the frame? Sure I agree with the fact that it isn't the most optimal setup for getting in an accident with it, but grade 8 bolts should hold it on the frame just fine. It might move out of place some but other than that, I don't know lol.

By the way, don't take that the wrong way:gathering:
 

Greybeard

Full Access Member
Joined
Jun 7, 2014
Posts
91
Reaction score
3
Location
Iowa-under a rock
First Name
Randy
Truck Year
75 something (maybe ???)
Truck Model
k10 and a 1/3
Engine Size
355
My personal biases I guess.

If they were dangerous the 'I'll save you from yourself' political segment or the MADD group would impose their greater intellect and vastly superior knowledge about all things off-road and make them illegal. They have on just about everything else...

Regardless, I never liked them, either the way the truck felt after installing them (the one I had was poly but it felt like sponge rubber) or the way they made a truck look, and to me they don't transfer a positive tight feeling from the truck. However, I have never owned or ridden in a truck with a 12" suspension lift so that may be a moot point anyway.
 

PrairieDrifter

Full Access Member
Joined
Dec 28, 2014
Posts
3,488
Reaction score
4,663
Location
North Dakota
First Name
Mason
Truck Year
84,79,77,70,48
Truck Model
Suburban k10, bonanza k10, c30 C&C, c10, gmc 1/2ton
Engine Size
350, 350, 350, 350, 350
My personal biases I guess.

If they were dangerous the 'I'll save you from yourself' political segment or the MADD group would impose their greater intellect and vastly superior knowledge about all things off-road and make them illegal. They have on just about everything else...

Regardless, I never liked them, either the way the truck felt after installing them (the one I had was poly but it felt like sponge rubber) or the way they made a truck look, and to me they don't transfer a positive tight feeling from the truck. However, I have never owned or ridden in a truck with a 12" suspension lift so that may be a moot point anyway.

I wanted decent lift but again I didn't want more than 4 inch suspension, and who knows I might not like it! But as for looks I do agree it makes the pickups look weird unless you relocate the gas tanks, but on the suburban it actually doesn't look bad, you can just see a bit more frame under the doors but that isn't bad. Then just get some good thick rubber for the fender wells, the worst part is the bumpers, the front isn't bad but the back bumper looks terrible after.
 

Greybeard

Full Access Member
Joined
Jun 7, 2014
Posts
91
Reaction score
3
Location
Iowa-under a rock
First Name
Randy
Truck Year
75 something (maybe ???)
Truck Model
k10 and a 1/3
Engine Size
355
Back bumper is solved with a good welder, a torch, a magnetic drill or really sharp drill bits and strong arms, a grinder and some salvaged black iron pipe and some plate.
 

PrairieDrifter

Full Access Member
Joined
Dec 28, 2014
Posts
3,488
Reaction score
4,663
Location
North Dakota
First Name
Mason
Truck Year
84,79,77,70,48
Truck Model
Suburban k10, bonanza k10, c30 C&C, c10, gmc 1/2ton
Engine Size
350, 350, 350, 350, 350
Back bumper is solved with a good welder, a torch, a magnetic drill or really sharp drill bits and strong arms, a grinder and some salvaged black iron pipe and some plate.

I was considering getting some oil field drill pipe, since its pretty heavy duty, and I can find it easily and cheap. I just have to figure out how to make it look good lol
 

Georgeb

Full Access Member
Joined
Apr 30, 2015
Posts
3,259
Reaction score
214
Location
Wisconsin
First Name
George
Truck Year
2003
Truck Model
K10 Burb Z71
Engine Size
5.3
If it were me I would fab some brackets that mount the step bumper up higher and incorporate a receiver style hitch below. Take somthing like a hitch for an 88-98 truck and modify as needed. The 88-98 hitch is wider than the frames on our squares.
 

Latest posts

Forum statistics

Threads
42,363
Posts
914,365
Members
33,861
Latest member
ebob14
Top