Frame reinforcing on an 03 F150

[ghank]

I heard from another F150 owner that you should reinforce the frame to prevent the cab from hitting the bed on big impacts. Well... Yesterday I jumped my truck for the first time and guess what... http://www.race-dezert.com/vb3/attachments/old/images/graemlins/blush.gif

Yep, the cab smacked the bed. Fortunately it's only a small 3 inch ding that I can fix, but it could have been worse and I want to go much bigger. I know once I modify the rear suspension it'll prevent some of this. But I want to reinforce the frame as much as possible. Wanting to keep most of the bed prevents me from building a full bed cage. So does anybody have any tips? Looking at the frame now I can see it is weak. And when I bottomed the rear axle it slightly dented the frame where the bottom out bumper is. The frame is a C section. I was thinking about closing the open side to make a more rigid box and plating the other side. Any thoughts on this? What type and thickness of steel would be preferred? I would love some input.

I also attached a pic of the truck if anybody wants to see.

[Solo1469]

when we plate a frame we use at least 3/16" or 1/4"...CroMo if you got it.

[ghank]

Now are you just plating one side? How does it look? Any pics? I of course want to optimize strength with as little weight added as possible. Thanks in advance!

[billymanfroy]

Well, I can only speak from experience on Rangers, but we took the time to box the whole thing front to back using 16 guage steel (I think it was about .110?") or as close as we could get to the thickness of the original frame. If you've ever lifted on one frame rail w/o the body on it you know exactly what I'm talking about. I seem to remember being able to literally twist the frame at least 8" without too much effort and it was plain frightening. The box job seemed to eliminate almost all of that flex. The only place I'd worry about plating the outside or top of the frame (doubling it up) is where your cage or shackles or shocks, etc tie in. Since you can't probably box the whole thing and don't want to do a real cage, you have to be very careful because you can actually create weak points by just boxing small sections. I would recommend at least going 12" or so forward of the back cab mounts with the boxing, and as far back as humanly possible.

If you weld tubes straight to the frame without doubling it up, ANY nerfring, etc. rips a hole in the frame or at least tweaks the crap out of it. The stock frame metal on old Rangers is damn near as bad a pot metal.

Good luck!

Billy

[hoeker]

that '03 f-150 actually has a very strong frame but no factory frame will withstand the abuse of jumping. your frame is already boxed on the front half, so that helps. any thicker than .125 on the rest will be a waste since the frame is quite thin already. your best option is a proper cage from front to back in the truck, even if it only ties into the cab below the rear window it will help imensly. if you don't want to do it right, leave the big air to propery caged trucks. at the very minimum boxing the rear portion of the frame will help, but don't think it will withstand anything you throw at it afterwards. good luck!

[ghank]

Hey thanks! Yah, I was thinking of tie in the shock cage in the bed to the back of the cab and eventually into the front cab and engine. I guess that coupled with boxing the rest of the frame should help. I want to do some racing eventually. I have no clue about classes or rules though. Any particular size tubing I should be using in case I start racing later on? What are the major racing sanctions in the southwest, particularly Arizona, Nevada and California?

[singlehanded]

Personally I wouldnt box the whole frame and if you dont know what your doing I would have a shop that knows what its doing do the needed reinforcement for you so you dont create weak spot on the frame.