Ok my b/f and I have a 1979 F-150 4x4 long bed. Well he is convinced that you can not to as many "jeep trails" with a long bed truck, so his plan is to cut 2 feet of the frame right behing the cab and make it a "short bed" he will obviously be cutting the bed 2' as well. Well last night he realized after taking the bed off the truck that the frame isn't just two straight pieces of metal, so now he talking about bending the frame to make it match up so he can weld it ( he is a welder ). He has only delt with welding a frame once when he welded a corvette front end on to a 58 chevy. If anyone has any kind of advice I would appriciate it!!! I don't want him to go to cutting on the frame w/ out knowing everything he needs to know

 

"Z" cutting the frame (down, across and down) instead of a straight chop will give you more weld area, also fish plating the inside of the frame web and bolting it for extra insurance wouldn't hurt. Some have gone as far as box plating the area.

 

Will this be ok for off roading?? or will it be too weak?

 

I've never liked cutting and welding a frame like that. Depending on where you live and if your planning on using the truck on the road you'll need to apply for a R title and go thru all the inspection stuff. What is he planning on doing with the drive shaft? Sounds like the project might get a little costly, even if he is a good welder. IMHO it would be a lot easier, and probably cheaper, to buy a short bed pickup or a Bronco

 

He said he already has all that figured out (drive shaft ect...) It will not be used on the road, just for offroad & 4x4. I was just wondering if it would be safe to weld the frame if using it for 4x4?

 

Let your boyfriend go at it. He is right about certain trails and long trucks. I run a Jeep Cherokee offroad and go places that even a shortbox truck couldn't. About the best offroad truck I've seen around here is a chopped 69 Chevy. Nice low hood and stuffs 40s on minimal lift.
People weld frames all the time. I don't know why so many people get uneasy about it. Sand rails and roundy round cars are fabbed out of everything. He just needs to make sure he takes his time and gets things square.
As for boxing the frame. I've seen whole frames boxed. Stock frames start to look pretty whimpy when your rig is banging through mudholes and jumping dunes.

 

I agree with 79_250RangerLariate, if you want a short wheelbase trade for one. F series are _very_ light and flexible in the chassis rails (which is what make them such capable off-road vehicles). Any cut and shutting of the rails will create stress points. With rigid boxed frames it's a different story, but if you box the welded section you'll reduce your flex and have less effective wheel travel.
Long wheelbases can be awkward to manoever, but they climb hills better. Incidently, every bent or broken F-series chassis I've seen has had the damage just behind the cab.

 

I say let him cut and weld it do the "z" cut or "/"as suggested and stagger the cuts if possible so they will not be directly across from each other. Make sure he bevel cuts them to get max penetration. I would also Plate the inside and box 1ft past either side of the weld. I know this is Major overkill but the welded area done correctly with the right rod will be the strongest part of the frame the rest is just sugar coating to make you feel better. You probably wont have to Box it but I would definitely plate the inside just because it is too easy not to do at that point. Just my .02

 

Thanks guys for all your help! He did cut it lastnight he did the "Z" cut, it is only going to cost 78.00 to shorten the drive shaft. He has it all welded up, just needs to plate it and box it, looks good!

 

The best of both worlds would be to shorten the overhang behind the rear wheels. You have to take a section out of the bed and reweld, but you don't loose any strength in the frame. You get a shorter truck with better angle of departure and the benefits of a long wheelbase. Oh well.... too late now.

 

I hope he took pictures to post in your gallery. I am thinking of chopping my supercabs frame to fit a short bed on it.

 

Since he is a welder, why doesn't he shorten the shaft himself? I did mine, and put pics in my gallery for how I did it. This way others can save some $$. Since it is offroad only, you won't notice vibration. Mine vibrates a little but it comes into a phase and goes out. It could be the tires or the old u-joints. I drive it both on the road and off, and it is fine. Just a thought.

 

He didn't do the "Z" cut.

 

I wouldn't worry to much about how the frame was cut (z would be preferred) but do make sure that you DIAMOND plate (<> shape) over the weld on one if not both sides of the frame. The plate used should be the same thinkness as the frame.
I wouldn't box the frame unless you do the whole frame. Boxing in a small area will cause weak points were the boxing stops, flexy frame then stiff, it will break were the boxing stops.

James