Anyone ever tie the frame together?

[troupp]

So like the title says.. Going to do 2" body lift this weekend, was wondering what would happen if I tied the frame from side to side with side 2x2 box tubing under the bed for more bed support, as my bed gets used quite heavily, and frequently(6,000 lbs stone at a time). or the the massive amount of frame flex on this long pig just going to tear up the tied in points? Turning into and out of my driveway I can watch the bed misalign itself anywhere from 3/4 to 1 1/2" depending on the angle of approach. And yes the bushings are currently good, it all appears to be frame flex. Any thoughts?

 

[jperecko]

if the frame is actually flexing horizontally... I would say you have a crack or are developing one. If you are talking twist, that can be addressed with adding some crossmembers. One option that would address both would be boxing the frame which would strengthen it all around but takes a good amount of skilled work.

 

[Alex S]

ya the long CC frames flex like a Mexican *****

 

[zpd307]

yes they do.....

 

[94f450sd]

boy do they flex!!!i can watch my bed drop below the cab on a hrad launch from a stop.you can do whatever you want to try to stop the flexing and twisting but all thats gonna happen is the frame will eventually crack and it will still flex/twist.they were designed to twist/flex not to be rigid like a medium duty and up truck.

 

[LCAM-01XA]

Actually even the medium- and heavy-duty trucks can twist some - the longer the frame the more twist it can handle and will do. And yes, these trucks have quite twisty frames, they don't even need to have the long wheelbase - mine for instance has more frame twist than it has suspension flex, the moment I put one wheel higher or lower than the other three and the cab and the bed stop lining up. Nothing out of the ordinary really, as long as the frame don't try to bend (bow) in the middle it's all good. Now if it is bowing when you load her up, then you gotta add some reinforcements indeed, but along the frame rails, and not across it - the factory cab-chassis trucks have double frames starting from under the cab to halfway under the bed for that very reason, but I'd imagine some 2"x2" square tubing and some 1/2" Grade-8 bolts can do the same job too.

 

[sootman73]

i thought the medium and up trucks were made to twist? its how the frame and drivetrain handled the massive amounts of torque produced and that it would destroy a lot of parts if it didn't flex?

my truck flexes a lot. like when my truck was being towed out of a pond(ya this story again) and the bed was.... well look for yourselves...

and it wasn't bent at all. came right back to where it was supposed to be. if it weren't for a flexible frame then it probably would have bent.

 

[Compu Doc]

ya the long CC frames flex like a Mexican *****

I wouldn't know about that because I never met a Mexican *****. Did you pay her in Peso's or US currency?

 

[sootman73]

 

[troupp]

I guess I shouldn't be worried about it then, I'll just add supports for the bed, and not worry about it.

 

[94f450sd]

Actually even the medium- and heavy-duty trucks can twist some - the longer the frame the more twist it can handle and will do..

they do twist a little but not much as most of them have some type of body bolted to them.with no body they twist worst than our crew cabs do

the factory cab-chassis trucks have double frames starting from under the cab to halfway under the bed for that very reason,.

that would be the chevy/gmc.ford has a strap on top of the frame rail from under the cab to the first crossmember.and i believe the same on the bottom.im too lazy to look at the cab/chassis wrecker sitting next to me

 

[88beast]

ya they flex prettty bad my standard cab 8 ft bed flexes a ton when i take it up the mountain so bad i need to readjust body gaps afterward but it always goes right back to normal

btw boxing a frame is easy it just gets hard when you have to work around the rest of the truck

 

[memphisrain]

Frame flex? What frame flex?

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mR

 

[sportsmobile88]

So like the title says.. Going to do 2" body lift this weekend, was wondering what would happen if I tied the frame from side to side with side 2x2 box tubing under the bed for more bed support, as my bed gets used quite heavily, and frequently(6,000 lbs stone at a time). or the the massive amount of frame flex on this long pig just going to tear up the tied in points? Turning into and out of my driveway I can watch the bed misalign itself anywhere from 3/4 to 1 1/2" depending on the angle of approach. And yes the bushings are currently good, it all appears to be frame flex. Any thoughts?

I don't want to sound too old or anything but I for one, am not a big fan of body lifts. The reason is simple: Leverage and a thing called sheer points.

The leverage that is exerted on body mounts with any real truck that is used to haul heavy loads is tremendous. Addind a body lift is like using a long prybar on each of the mount holes. I put one on years ago on a now long dead truck i owned and it literally tore the body apart. It had stress cracks around every mount.

The second point is sheer. A body lift will add an additional sheer point on each of the mounting bolts. If there is a good sized impact, you have added an additional point for the bolts to sheer or break. I've seen it first hand with my friends truck that got T-boned and it sheered all the bolts off one side of the cab and bent the rest. It was a one year old truck with perfect rubber body bushings and a 2" body lift professionally installed by a big name shop.

If it's just tire clearance issue, I would consider other options such as bigger springs or high-cut fiberglass fenders such as these:

http://www.hannemannfiberglass.com/custom.asp?id=457567&page=47

That's just my 2 cents.

Beware of welding on a frame as if done incorrectly, may cause thermal embrittlement which leads to cracking/breakage issues. Bolt on may be better as long as existing holes are utilized and no holes are drilled to weaken the frame.

 

[LCAM-01XA]

that would be the chevy/gmc.ford has a strap on top of the frame rail from under the cab to the first crossmember.and i believe the same on the bottom.im too lazy to look at the cab/chassis wrecker sitting next to me

Nope, Fords have it too, that's actually where I saw it first - I was under a cab-chassis F350 with a 12ft flat bed taking off a steering damper, when I noticed what looked like plates welded to the inside of the frame rails, upon closer inspection it's actually a second pair of smaller frame rail pieces riveted to the regular ones on the inboard side. I remember wondering how hard it would be to find a pair of these and adapt them to my RCLB truck...