Fj40 boxing frame?

[White Stripe]

I'm replacing the 3/4 tub on my cruiser and am considering boxing the frame. Seems like my frame is slowly flexing more over the years. Has anyone did this and did it reduce frame flex? I am also considering welding up the mid frame channels that I can access while the tub is off to reduce flex. I won't be able to get to the front section easily so Im thinking of leaving that for now.

 

[shawnfj40]

There is probably no good reason to box in a 40 frame. they are supposed to flex a bit.

 

[White Stripe]

There is probably no good reason to box in a 40 frame. they are supposed to flex a bit.

My hood slides about 2 inches per side as the suspension articulates. So it slides a total of 4 inches. This seems a bit excessive. The sheet metal where the hood meets the front rubber insulators has worn thin from all the rubbing. My hood hooks are tweaked because they get over stretched.

 

[A10Driver]

Box it, but make sure your suspension is good. I am a firm believer that the suspension is supposed to flex and not the frame.

 

[shawnfj40]

If you decide to box it in just remember to do the whole thing. The place where you stop will be the place all of the tension is transferred to and the frame will break right there. It really is an all or nothing project.

 

[jim land]

my frame is boxed and the cage is bolted to it , also custom bumper front and rear and custom skidplate , it give more rigidity .

Body lift make things worst , you can lower it or use nylon puck

my hood slide is about 3/4 to 1" some pics for you

 

[jim land]

one more

View attachment 1416961

 

[White Stripe]

one more

View attachment 1416960

View attachment 1416961

Do u have any pics of your frame? Thanks for the flex pics.

 

[White Stripe]

If you decide to box it in just remember to do the whole thing. The place where you stop will be the place all of the tension is transferred to and the frame will break right there. It really is an all or nothing project.

Thanks. I found some info as to what fc customs does with cruiser frames and will just copy him. I should be able to access quite a bit with the tub off.

 

[jim land]

i did not find a clear pic, but i just box the rear part of the frame with 1/8" plates , back when i did this was before internet so i made my plates with a cutting wheel , dont waste your time and call ruffstuff

 

[offrd63]

I've thought about doing this for a long time too. The thing holding me back is not knowing that my frame is straight before I weld it up. It seems like it should go up on a frame rack and be clamped in place before I start welding

 

[White Stripe]

i did not find a clear pic, but i just box the rear part of the frame with 1/8" plates , back when i did this was before internet so i made my plates with a cutting wheel , dont waste your time and call ruffstuff

I ordered the ruff stuff kit. I just wish it had more access holes in the side plates. I guess I'll cut my own.

 

[shawnfj40]

My hood slides about 2 inches per side as the suspension articulates. So it slides a total of 4 inches. This seems a bit excessive. The sheet metal where the hood meets the front rubber insulators has worn thin from all the rubbing. My hood hooks are tweaked because they get over stretched.

Is your tub toast or just the usual spots? Some of your frame stiffness comes from being bolted to the tub.

 

[White Stripe]

Is your tub toast or just the usual spots? Some of your frame stiffness comes from being bolted to the tub.

The tub is still very solid structurally. Has some mild rust. I'm going to a aqualu 3/4 tub though because I don't have shop conditions to take on rust removal on a tub again.