Frame Splice

[drcomanche]

Currently, I have a truck with some severe rear end frame rot that pretty much has it dead in the water. I did happen to find a guy selling a "frame as far up as I need as long as I cut it out" and the frame is in excellent condition. I was hoping to get some information from the fabrication side of the club about what is entailed in splicing the frame and what I will need to do to ensure it holds up. I would be cutting the entire rear frame and about a foot under the cab off and welding fresh materials on. 

[neohic]

Ask freakjeep93!... for anyone who's been around long enough to remember that, anyhow. :laughin: Boy, I've been feeling old lately.

 

There are a few good threads here where others have plated their frames. It really comes down to removing everything that isn't good metal and cleaning it before welding. Some nice long fish plates are also your friend here along with thinking through your cuts to make sure everything goes back together properly. Here's some stuff to think about at while crawling under your truck with a square and tape measure...

 

Z-cuts:

 

These are to extend any stresses of cutting over a larger area. They also make it easier for lining things up again if you do a good job of measuring.

 

Fish plates:

 

See the ends how they come to a point? Those are also there for moving stress points. Welds don't like straight lines that are perpendicular to a long frame... it'll only crack in the future. Plug welds aren't a bad idea either. They further tie in the fish plates to the good material under them.

 

How far back to add in new metal:

 

Cleanliness! CLEANLINESS! CLEANLINESS!!!... cannot be stressed enough.

 

Grab a chipping hammer or a punch and just start knocking around under there. Does it poke through? Soft? Then grab a grinder and just take off the layers of under coat and paint. The frame shouldn't look pitted at all if you have intentions of welding over it. If it were me, I'd tie in at least a good 6-8" of known solid steel with my fish plates. Before any cutting starts though... ANY CUTTING!!!  :smart: ... make sure that the frame is level and make a good road map of some dimensions that you can refer back to when it comes to start gluing it all back together.

 

How about some pictures of what you're working with?

[drcomanche]

I'll grab some pictures a bit later today if I can. It pretty much covers about 6 inches under my cab all the way up to where the bump stop mounts for the rear leaf. Plus the cross member is looking a bit worse for the wear. My intention is to weld on this new piece(which is all inclusive. It is the entire rear of the frame, cross member and all) and to sleeve everything out after doing the initial repair to bulk up the frame all together.