Too much frame flex

[379redneck]

Anyone have any cheap/easy ways to get rid of some frame flex? Ihave been getting my truck pretty twisted up lately and just noticed how bad teh flex is, and found several stress cracks in the cab behind teh seat. Im looking at putting hitches in the front and rear and rock sliders to start, but even that will be a little bit fromnow. I dont realy want to box the frame. the end result proboly be a full exo cage.

[379redneck]

Heres some pics for ya

[bk2life]

Originally Posted by 379redneck

I dont realy want to box the frame. the end result proboly be a full exo cage.

exo cage will help alot. as would boxing the frame.

these chassis arent made to do what your doing, you could weld all crossmembers (they are riveted) and weld in new crossmembers, but ultimately its a huge c-channel and will need serious reinforcments.

[379redneck]

I would box it, since that alone would get rid of almost all of the flex. My issue with boxing is the whole mud/moisture problem, I dont want to have the frame rot out cause I cant get in there to clean it.

[john@thepier]

Flex = tires on the ground, why would you want to stiffen it?

[379redneck]

Because it's cracking the cab, otherwise I wouldn't care. The flat section behind the seat is bent up, down, and cracked in several places.
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[special-K]

That kind of wheeling puts a hurtin' on a truck...period. Gotta expect some battle wounds...period. If your frame isn't flexing it will be cracking or bending. You have to decide,for that kind of wheeling,if you want a street rig or a trail rig. Cuz once you start beefing the frame you have to do it right or you'll put too much stress on one area. Gotta go all out or stop playing so hard. At least that's my take.

[theastronaut]

I'm bracing the frame on my '66 to keep it from twisting as much. Using 1x2" tubing in an X shape, will have two x's for the upper and lower flanges of the C channel when finished, then the two will be tied together. I'll also make a pair to go in front of the trailing arm crossmember and wrap around the transmission.

Laid out with string to check clearances.

[379redneck]

Originally Posted by special-K

That kind of wheeling puts a hurtin' on a truck...period. Gotta expect some battle wounds...period. If your frame isn't flexing it will be cracking or bending. You have to decide,for that kind of wheeling,if you want a street rig or a trail rig. Cuz once you start beefing the frame you have to do it right or you'll put to much stress on one area. Gotta go all out or stop playing so hard. t least that's my take.

I dont mind some damage but I also dont want the cab to get severely messed up, or anything else on the truck if I can prevent it. I want to do it right, but I want to do something to temporarily help it a little until I get to start it. The truck is going to be mostly a trail rig but also kinda road worthy at the same time, with a few broken rules here and there if the cop is in a bad mood. Im not going to trailer my truck to the woods.

theastronaut, I was actually thinking about doing that but using the braces off a section of frame from a 5 ton.

[argonaut]

I'm not really sure a flat x like that would really do much to resist torsional effects on the frame.

For a cheap fix I would weld all the existing corssmembers and brackets to the frame rails. not really pretty, and not easily reversible but it would help.

You could also install some large diameter round corssmembers. You see these on some of the newer trucks. A through hole is made in each frame rail, then a tube inserted through these holes from one side to the other, then welded to the rails. Round tubes resist torsional loading better than any square or rectangular shaped tubes or channels. Unfortunately these crossmembers won't cure the problem as they aren't oriented along the axis of torsion that your frame is exposed to, which is front to back.

As others said, building a full, well designed cage, will work the best to eliminate flexing. The key here is having a good, well designed, flexible suspension, otherwise a stiff frame won't help your offroad traction.

[beardface]

What kind of body mounts do you have, and what condition are they in? Polyurethane mounts are popular, but they are stiffer and would transfer more force to the cab. And old worn out mounts wouldn't help either. I've seen a truck with valve springs in place of body mounts to allow more frame flex without bending on the cab.

Changing body mounts is probably easier than welding on the frame.

[k5xjfiles]

No one mentioned suspension. If your spring rates are too stiff.....the frame is making up for it. If you had more flex....it would be less stressful on the frame.

[Stocker]

Originally Posted by k5xjfiles

No one mentioned suspension. If your spring rates are too stiff.....the frame is making up for it. If you had more flex....it would be less stressful on the frame.

Agreed... for the record, argonaut mentioned suspension two posts above yours.

[theastronaut]

Originally Posted by argonaut

I'm not really sure a flat x like that would really do much to resist torsional effects on the frame.

There will be two X braces, an upper and lower that are tied together. Then another pair of X braces in front of the trailing arm crossmember (my '66 has trailing arms, leafs would be different). The picture with the string shows the layout in the rear. Upper and lower X's welded to the upper and lower flanges of the C channel, with both braces tied together won't let the frame rails twist.

[379redneck]

The body mounts are very worn, ive been meaning to replace them for awile. The truck has 6'' superlift springs in the front and stock springs in the back with blocks. The front flexes great, its actualy destroying my fenders but the rear doesnt seem to flex until the frame gets messy. Acage will definately be going on it, I destroyed the passgenger side door and bedside on a tree last night. Now I have one the doors im going to use for my half doors

What would be good mounts to go with and good springs to use?

[special-K]

Does Superlift make flexy springs now? I was a big fan of theirs years ago,but when I bought springs they were like Rough Country and only offered the same old stiff springs. The rear stock springs with blocks gives no improvement over stock,which are designed to haul loads. There are flexier springs on the market,mount kits to install longer springs front/rear and shackle-flip kits for the rear. This is the direction I'd take,then,if the frame still flexed too much I'd start solving that.

[379redneck]

I looked on their site and couldnt find any. Ill look around more to find some better springs.