Crooked bed?

[MannyDantyla]

there are no body mounts under the bed though. My older brother tried chasing this problem when he bought his truck new back in '83. I seem to recall he finally found out that it was built like that. someone screwed up a blueprint somewhere in the design stage and no one noticed until they started rolling off the line.

WHAT?!

My '83 bed is uneven too! Wow, can't believe GM ****** up. At least I don't have to worry any more about the frame being bent. There are no body mounts under the bed, at least not for my year 1983.

I think I'll try shimming it when I have more time.

 

[CSFJ]

You can't believe GM screwed up? Haven't worked on a lot of them huh? Lol. I think the easiest way to go would be to level the bumper to the body. Even if you have to slot the holes where the brackets meet the frame I would think that would be easier than trying to shim the body and get all the body lines even.

 

[WillSquared]

The more ive looked at mine I just dont know. I already had to remove some shims from the rear of the right side of the bed which helped a little but its still crooked. If you just stand behind it, it looks like the rear passenger side corner back by the tailgate is lower than the rest of the truck, but the bumper sits lower on that side than the driver side so I just dont know at this point. Im afraid if I shim the drivers side to even out the bumper/trim spacing that it will look even worse.

I replaced the tailgated hinges thinking maybe that was causing the tailgate to sit uneven but no, it still sits the same, only worse really because now my body gap on my drivers side is probably 3/8" and its very tight to shut on the passenger side now.

So basically, I dont know what the hell Im doing anymore and at this point Im thinking of attempting to modify the bumper brackets over on the passenger side to just make everything sort of line up.

 

[MadOgre]

jack the frame off of a flat surface with jack stands measure to make sure it s pretty level on all four corners.

Then go under the truck and measure from the floor of the box to the frame to check for bent, squished or deformed bed channels.

Measure the box sides to ensure that they are the same height from the box floor from side to side and that their over all height is the same

Then ensure the tail gate matches the bed sides by replacing the tail gate hinge hardware to align it properly

At this point if everything checks out

Then measure from the top of the bumper to the top of the bed sides(not the tail gate) And adjust the bumper to match. Often the bumper brackets for both front and back are slightly bent causing even a new bumper to appear crooked.

This is often the issue accompanied with worn body mounts, sagging suspension which flexes the frame and sometimes the after market replacement panels very in dimensions which can also throw lines off.

 

[MadOgre]

The more ive looked at mine I just dont know. I already had to remove some shims from the rear of the right side of the bed which helped a little but its still crooked. If you just stand behind it, it looks like the rear passenger side corner back by the tailgate is lower than the rest of the truck, but the bumper sits lower on that side than the driver side so I just dont know at this point. Im afraid if I shim the drivers side to even out the bumper/trim spacing that it will look even worse.

I replaced the tailgated hinges thinking maybe that was causing the tailgate to sit uneven but no, it still sits the same, only worse really because now my body gap on my drivers side is probably 3/8" and its very tight to shut on the passenger side now.

So basically, I dont know what the hell Im doing anymore and at this point Im thinking of attempting to modify the bumper brackets over on the passenger side to just make everything sort of line up.

Often shims are used to correct lines when a vehicle has been hit. You can shim off of a bent frame to correct body lines. how ever you will always notice funny things like bumpers that don't quite line up properly.

Factory vehicles did not come with shims under the body.

 

[WillSquared]

According to carfax it was hit bad enough to report back early in its life, like 89 or so I wanna say. Front end collision it called it but it has a clear title. Idk if the frame got tweaked or what at that point. It runs down the road fine and I've seen no other symptoms of a wreck aside from just normal dents in random places. It did have shims though back between the frame and bed, but they were on the side that's taller at least in relation to the bumper.

When I get a chance I'll jack it up and investigate further.


Sent from my iPhone using Tapatalk

 

[MannyDantyla]

I just looked under my bed and there's some shims under some of the bolts. I'll have to do some shimming soon too.

 

[Big red square]

I was just looking at a set of body mounts near a rear bumper, but now realized it was on a suburban. If frame is not twisted, then I think there might some play in the bumper brackets where they bolt to the frame for adjustment.

How could i tell if my frame is twisted?

 

[yevgenievich]

How could i tell if my frame is twisted?

Measure same points diagonally across the frame. There should also be reference measurements in a body manual

 

[Keith Seymore]

Factory vehicles did not come with shims under the body.

Ackshullly -

They did. Just like the shims we would use to fit fenders to the body, we would also place shims under certain body mounts if the cabs were building off.

We would run that set up until the repair area called back and told us to remove them or move them somewhere else.

Also - the development community would recommend shims under certain mounts to fine tune the rates and affect various vibrations or noises. Those would be added formally and could last the entire model year or until some other design element was changed.

K

 

[Keith Seymore]

We had "box lean" when vehicles were new.

Typically upper management would get all excited about it and we would launch into some deep, involved design study. Then, usually before we figured anything out, they would be off on some other big concern and those resources would be reallocated to the next big thing (eg vent wind noise, or door closing effort, or some other "hardy perennial").

I put 1/4" spacer between the leaf spring and axle on my low side.

Done.

K