Diagnosing and fixing bent frame? (1 Viewer)

[LazarusTaxa]

I am curious how I can determine if my frame is bent or twisted... Basically, if you are looking at the truck head on and focus on where the front bumper lines up with the valence panel, the sight line of the bumper against the panel is about a half inch higher on one side than the other.

I recognize this could be due to a lot of factors... Panel alignment, worn out body bushings, etc... But could this also be due to a twisted frame? Is there any way to diagnose this other than taking it to a body shop with a frame jig?

And, assuming it's slightly twisted, is this something that can be fixed easily?

Here is an exaggerated picture of someone else's truck with some lines drawn on it:

Any experience is appreciated...

 

[cps432]

Well your red and yellow lines are not straight and they aren’t following the lines of the truck very well so that’s not a good indicator of what may be going on.

1980 Land Cruiser Chassis & Body Repair Manual (38044E)

1980 BJ40 FJ40 BJ60 FJ60 Land Cruiser Chassis & Body Repair Manual (38044E)

content.cruisermanuals.com

This partis of the fsm shows the factory frame measurements. If you have any problems with the frame this is your best reference.

 

[diesellibrarian]

Looks ok to me, but if you determine that something's out of whack, I would look at your body mounts before worrying too much about a twisted frame.

 

[cps432]

Looks ok to me, but if you determine that something's out of whack, I would look at your body mounts before worrying too much about a twisted frame.

Agreed. You will be surprised what a new set of body mounts will do for your ride. Toyota still has them but you’re paying over $600 or you can get a set of polyurethane bushings from 4crawler.com for about 250-300 depending on what hardware you choose.

 

[LazarusTaxa]

So, as mentioned, keep in mind that pic is not my truck... Its raining so I didnt take one of my own..

Well your red and yellow lines are not straight and they aren’t following the lines of the truck very well so that’s not a good indicator of what may be going on.

1980 Land Cruiser Chassis & Body Repair Manual (38044E)

1980 BJ40 FJ40 BJ60 FJ60 Land Cruiser Chassis & Body Repair Manual (38044E)

content.cruisermanuals.com

This partis of the fsm shows the factory frame measurements. If you have any problems with the frame this is your best reference.

Yeah, I have the factory measurements, but without a flat level plane to measure off of, I'm not sure how to use them?

Looks ok to me, but if you determine that something's out of whack, I would look at your body mounts before worrying too much about a twisted frame.

Could be... But, I'm getting ready to take the body off to get the rusty frame blasted and painted and want to be sure it's good to go before I invest all that effort

 

[cps432]

So, as mentioned, keep in mind that pic is not my truck... Its raining so I didnt take one of my own..



Yeah, I have the factory measurements, but without a flat level plane to measure off of, I'm not sure how to use them?



Could be... But, I'm getting ready to take the body off to get the rusty frame blasted and painted and want to be sure it's good to go before I invest all that effort

If you’re that concerned about it and you’re going to be doing all that work, it would be worth it to buy a machinists straight edge to measure and determine if things are copacetic. A really nice straight edge is valuable for many different applications. And you’ll be glad to have one once you see how handy they are.

 

[kirvesmies]

So, as mentioned, keep in mind that pic is not my truck... Its raining so I didnt take one of my own..



Yeah, I have the factory measurements, but without a flat level plane to measure off of, I'm not sure how to use them?



Could be... But, I'm getting ready to take the body off to get the rusty frame blasted and painted and want to be sure it's good to go before I invest all that effort

make a flat level plane n work off that. use it as your index point n do the math. it's quite simple. h3ll, race cars are built with plywood jigs n string lines

 

[cps432]

When you get a chance after the rain snap some pics for us of the truck and the body mounts. These frames are really well made and it’s unlikely it’s twisted, but that isn’t certain. My vote is on body mounts causing things to sag and giving you optical illusions. I was genuinely surprised what new body mounts accomplished.

 

[kirvesmies]

if you want to get unadulterated numbers, you're best to separate the frame n body before you start checking as i believe the body could twist the frame when fastened to it

 

[2mbb]

Other than esthetics, do you have some indication this is effecting the performance or handling of your truck? The front bumper stays, although riveted onto the frame are replaceable and different configurations for non-winch and winch OEM bumpers. Also I think the bumper stays are exposed and more likely to get bent.

If it's the bumper you are worried about, take it off and specifically look at the stays. and you'll also be able to inspect the front frame rails and bracing.

 

[cps432]

I tapped a tree with the front bumper while wheeling a few years ago and it bent the bumper and the stay on the passenger side. I didn’t notice the bent stay until it began rusting differently than the other side.