we have doubled up the frames when installing the ram on a dump truck and all the boom trucks i worked on were
sleeved frames at least till the early ninities. and you are correct they were sleeved only in the high stress areas.

 

Ya your right a dump truck and boom truck etc. heavy trucks like that that have the heavier axles and etc would be double framed all the way through. We have a couple heavy spec'd trucks that are late 90's but the frame is only doubled at the front by the engine and at the rear ends. We had some late 80's trucks that were also heavy spec'd and they had double frames front to back.

Trucks have many cross members going along the frame connecting both sides im not sure how well added more cross member on and etc would work. It would be very difficult to double frame one of these trucks because it not flat c channel all the way down its curves and bends and all kinds of stuff. It would be very difficult to do it, everything would have to be stripped and new holes drilled through the frame insert. I sure hope if someone was to go that far they would atleast powder coat it to make it last and look good.

 

Another way to strengthen a frame or I beam for that matter is to make the flanges thicker. So just plate the upper and lower flanges with 1/4" x 2" or
3" plate.

 

about time to build a jig and start fab. frames from scratch all tube construction. wish i won the lottery.

 

I have also seen them "Bridged".

I hope I can explain this.

They take a length of strap-steel that is about two inches above, or below, the frame, and about every foot, there is an upright stand-off spacer that ties the strap-steel to the frame.

The extreme ends are angled to the frame and welded.

There is a welding shop, near here, that does several of these each year, trucks and trailers.

If I wanted a stouter frame, I would just discard the crooked stock frame, and build a far superior straight C-channel frame, like on a big truck.

Everything else ever done to the truck would be much easier.

 

What would you do about lengthening a frame for a car carrier body as I have thought about building mine into a car hauler??

 

Myself, I wouldn't ruin a good truck and limit it's usefulness by stretching it and dooming it to a life of hauling cars.

Instead, I would invest in a real good trailer that I could hook to, when I wanted to haul cars, and un-hook and leave sit, when I wanted my truck for all the many other things that I would use it for.