Bumper & Frame Issue

[Georgeb]

Seems to me most solid axle 4X4s do lift on one side when turned sharply. Doesn't that have to do with the caster? The more positive the more it will tend to lift?

 

[Georgeb]

Seems to me most solid axle 4X4s do lift on one side when turned sharply. Doesn't that have to do with the caster? The more positive the more it will tend to lift?

Could the effect be increased by the installation of a lift?

 

[firebane]

Seems to me most solid axle 4X4s do lift on one side when turned sharply. Doesn't that have to do with the caster? The more positive the more it will tend to lift?

Honestly it feels like its going over small bumps... Its a really hard feeling to describe.

 

[Georgeb]

Interesting! As far as the frame and bumper goes. I agree with Chengny on getting it assembled and moving on. I think the steering issue is separate from the frame issue. After all our trucks are rarely on a surface that is flat enough to really notice the difference you see in the frame horns.
Just my opinion and you know what they say.......

 

[firebane]

But here is my thought if one front of a spring is higher or lower would that not pull the axle in one direction or another?

for example the left side spring is higher so the axle would be pulled further forward compared to the right side?

 

[Georgeb]

But here is my thought if one front of a spring is higher or lower would that not pull the axle in one direction or another?

for example the left side spring is higher so the axle would be pulled further forward compared to the right side?

How much higher?

 

[Georgeb]

Yes, tehnically it would pull the axle forward. Probably not much tho. Besides the spring will want to arc up before it would move forward. I dont think the small amount of difference is going to be all that noticable. Think about the front suspension used on leaf sprung jeeps. When that suspension flexed the axle moved forward but at best only maybe by a 1/2" max in stock form. If you can square your bumper to the ground and make the body line up with it just call it good....

I realize the steering setup was different on the jeeps but as you drive verses sitting static parked all that stuff moves around all the time. If it doesn't dog track real bad there is probbably nothing to worry about.

 

[firebane]

Well first off I gotta say whomever put my rear bumper on is a massive **** sucker. Not only did they bolt it on but they put 2 3" pipes WELDED to the bumper AND to the frame. That was not fun.l

Anyways here are some measurements I pulled off and if you need pictures to reference let me know.

Both rear axles are at exactly 13 3/8 from axle to frame so the back end is fine.

On the front both left and right side are ground to bottom of fender opening measure at 40".

Regarding the spring bolts on the front I measured 21 1/2 on the left side and 21 3/8 on the right side for a difference of negligible for that spring bolts.

Axle to frame is 12.15" on both sides

The elongated hole on the front of the frame horn is 26 3/8 on the left side and 26 1/4 on the right side..

For the bottom hols to attach the bumper it is 26" on the left side and 25.5" on the right side.

At the body mounds for the rubber at the top it is 28 1/8 on the left side and 27 5/8 on the right side.

So this does in fact say that something is tweaked but perhaps not the frame but at least the left frame horn AND the front cross member with the sway bar mount holes.

Also due to the difference in the body mount brackets means if I do replace the body bushings there is going to be a lot of shimming going on.


Thoughts?

 

[Georgeb]

IF it was mine and it drove fine shims it would be. Whatever happend to it to cause that much movement probably wont happen again unless you get it super stuck and jerk it out REALLY hard or jump it and generally drive like an asshat.
My red 87 R 3500 took a hit from a jewp that moved it 35'. There is no doubt stuff moved but if I can get it to drive straight I am going with it as is. I will space and shim as needed to make it look good and move on. It's not like it will spontainiously fold in half one day.

 

[firebane]

So here is a question. If I want to say fix the horn do you guys think it would be ok to make cuts into it so I could hammer it back to where it WOULD work because not only is the bottom hole out of skew so is the top because of the bracket that needs to go on.

I'm not sure how I'd cut it but I would probably do a front to back cut along the outside edge and follow around to the front. This would allow me to knock the top down and then reshape the bottom. Once done I could weld it all up.

Also maybe what I could do is get the body bushing kit and put the cab bushings in then figure out how much difference there on the front and then pull the rivets and use grade 8 bolts and move the body mounts.

From a quick glance it looks like the body mounts and spring perch are individual items which could be pulled a part and rebolted together as well.

I would also be locating a new front cross member and sway bar mounts and install that as well.

Thoughts?

 

[Georgeb]

one question. Has there been any work done around the steering box? They usually have frame issues there.....

Your plan could work but welding it as it sits is out of position so idealy I would think it would be hard to get good penetration. Plus using the correct filler and heat will be impoertant. A half inch seems like a ways to go using that method.
If you can go up 1/4" with the bumper on the right and down 1/4" on the left you can make up for the difference.

Your measurements explain why that right core support mount was done like it was. Seems like someone compensated for this issue already. If you make it the same as the left you may have door to fender gap issues. I would not elongate any suspension bracket holes in the process of trying to fix this either.

 

[firebane]

one question. Has there been any work done around the steering box? They usually have frame issues there.....

Your plan could work but welding it as it sits is out of position so idealy I would think it would be hard to get good penetration. Plus using the correct filler and heat will be impoertant. A half inch seems like a ways to go using that method.
If you can go up 1/4" with the bumper on the right and down 1/4" on the left you can make up for the difference.

Your measurements explain why that right core support mount was done like it was. Seems like someone compensated for this issue already. If you make it the same as the left you may have door to fender gap issues. I would not elongate any suspension bracket holes in the process of trying to fix this either.

No work at the steering box but when I was taking measurements tonight I could see in the frame near the steering box a warp in the frame.

Also there wouldn't be a 1/4" gap to fill with the frame horn. The reason for this is that not only does the top need to come down the bottom needs to come up. So by cutting the frame horns you would hammer down the top and hammer up the bottom to get everything to line up. There would be minimal amount of gap left that would require any welding at all and the frame horn would be fixed.

Regarding the brackets if the spring hanger and body mount are different brackets you could then ensure the spring hanger is where it should be which it is but by putting on the cab bushings you could then see how far out the two under the rad mount would be and could either adjust the brackets if needed or shim it of which I think shimming would be the easiest course of action.

I will have to find a good front cross member and sway bar brackets too at some point as those will need to be replace properly.

Here is the frame damage:

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[firebane]

Ok so more to add to this damn story and it really is not looking any better. I have temporarily made it so I can mount the bumper and I mounted the bottom bolts. Upon doing this I came upon two issues that showed up ( can provide pictures if people want).

#1 - The bumper sat closer to the right fender than the left fender
#2 - The bumper is further out on the left side compared to the right side

So I found the center of the front cross member roughly then took two spots on the frame rails and measure. From the rivet to the center of the cross member on the right frame I get 16.75" and when I do the same for the left side I end up with 16".

So there is a difference of 3/4" which to mean now tells me that not only is the left frame rail pushed up but it would seem as if BOTH frame rails are pushed to the right.

Anyone have any other spots I could reference to measure to see if the frame horns are shifted towards the right side of the truck?

Front the lip on the hole for the signal lights to the edge of the bumper I get 5" on the left side and 4" on the right side telling me something is 1" out of whack as well.

Straight on (I know its lower on the left side I need to still make adjustments to the frame):

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Left side bumper:

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Right side bumper:

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[MadOgre]

You should browse through this

http://www.gmsquarebody.com/forum/showthread.php?t=12851

 

[firebane]

You should browse through this

http://www.gmsquarebody.com/forum/showthread.php?t=12851

So basically you gave up and did a frame replacement. If that is what this is going to take then I am just going to part this thing out. Trying to find a frame where I will be next to impossible.