Hello. I have a 96 F150 4WD extended cab. When 4 wheeling over VERY uneven terrain I can see the bed move several inches from side to side. Is this normal? Should I try to add stiffeners to it? Thanks.

 

Yes and that F150 frame is undersized to begin with, frankly not designed to accommodate the type of "off roading" many endure. The whole shooting match weakens over time and if heat has ever been applied over its life, temper is affected further reducing strength. When you "off road" you add vertical, axial and lateral forces Ford's engineers simply didn't account for..........

 

That's not the impression I got watching the old Ford truck commercials where a Ford 4X4 goes up a very rough hill with a Chevy tied across the bed.

 

That was an F-350, not an F-150 in that commercial. And it was a commercial.

 

Ford engineered the frame to flex as part of the suspension

It is very prominent on 2 tone truck as the body lines almost never line up

 

I knew that commercial was BS even when it was on TV back then.

 

This begs a question for me:


I take my F-150 4X4 into some pretty rough terrain & have never noticed any flex to speak of. Doesn't skill & care while driving in these conditions come into the equation? I have seen some pretty tweaked up 4X's, but their owners drive them like hot rods in rough terrain.

 

The 85 I had wasn't a 4X4, just a basic truck with the 300, manual transmission and 8 ft bed. It did OK off road and I only saw minimal bed movement in my mirrors. The roads I offroaded were nothing too extreme.

 

Mine did all the time, but I was hard on the ole girl.

 

Now that is a lot of flex

 

Yes and no. I had an '85 F-250 and even brand new I could easily get about 4" of misalignment in the body by getting it crossed up. That's crawling, not beating on it hard. So that's the "no".

The "yes" is that if you beat on a truck long enough the body mounts will start to fall apart and you might start to get cracks in the frame, and it will flex more as it gets "loosened up."


By the way, while my '85 F-250 probably had a stiffer frame than a '96 F-150, it also had less compliant suspension, so there was more torque being put on the frame when I crossed it up. So it's not necessarily clear which would flex more on the same terrain.

 

UM, that is MORE than frame flex. That is either a broken frame, rotted cab mount or missing bed bolt.

There is no way the fame can flex that much within a 6" span

 

My money is on the cab mount being bad/broken. I would think if it was the frame he would have REALLY tore it up by now!

 

You think you've seen frame flex, go wheeling with a CCLB with a broken core support mount. Like Brad said, they flex, not to say they are designed to flex but they aren't designed not to flex, it's flex or break, Ford choose flex. I do wish mine flexed less though. There's a lot of factors, a big one being the body. Like I said I have a broken core support mount, so I get a good 6" extra gap on the side of the broken mount, also when I put the bed back on I only put in 4 bolts to kinda let it flex, this turned out to be a bad idea, I broke my fiberglass canopy cause the bed flexed too much, couldn't open the tailgate with it flexed either.

 

As long as it don't look like Puddy's picture above then you're good. Mine flexes off-road as well, as did my 94 F-250. Like BruteFord said, it's either flex or snap.

Mine had a cracked engine cradle. I tested my repairs by crossing a ditch at a 45 degree angle 2 or 3 times, which is pretty hard on a frame and something I try to avoid if I can go another way, but even then she didn't flex THAT much.