99 4964 Frame Crack Suggestions

Nope they're definitely steel, and there's no boltholes to "waller" out

I've attached a screenshot. This isn't the exact crossmember, but the design is almost identical. It looks like they bolt the flanges on the truck, square the frame then weld around the eyes to secure it. I looked at mine outside, it's only welded all the way around the eyes you see in the picture, but gouging those apart would be creating more work I feel. I'm going to do some calling in the morning and see what I can get my hands on for material. At this point I feel installing as big of an insert as I can without hitting the crossmember, and cutting the ends to 45 degrees may be the way to go. I can add a few bolts, and certainly monitor the outside frame rail to ensure cracking doesn't reoccur. The only shortening necessary would be torque rods, which I can do. On the right side rail the crack is after the rear crossmember, so I'd only be able to come to it anyways.

 

I hear you, and certainly value the input. I just don't see a way of doing it that won't potentially open up another can of worms. Kinda wish I'd found these cracks sooner.

 

Thanks for the input. At this point I don't think there'd be any value in splicing the frame with a new one. I'd be introducing two different areas for fatigue (vertical vs horizontal cracking) and a heck of a lot more work/money too. The rest of the suspension is intact with no cracking, so there's no point in going that far in. If the suspension did ever completely fail I'd likely be swapping it for an AR2 setup out of another truck.

Rolling on the outside isn't an option either. It would interfere with all the rear suspension.

I really don't like the idea of not inserting at least the full length of the drivers, so I'm thinking the best solution may be to cut the rear crossmember in the middle so it can be removed, shorten both pieces by 1/4", then reinstall and weld in-truck with a fishplate over it. That would get me the necessary clearance for the inserts, and also allow me to run full length inserts.

The forward crossmember is a tube-in-socket type deal. I'm pretty sure I can gouge the welds off it and simply re-weld.

 

Correct me if in wrong, but I believe the frames are heat treated, not tempered. It they were tempered they'd shatter after a certain load point. Heat treating makes the frame more flexible, but with a memory so it springs back after load. I don't believe the crossmember is heat treated or tempered. Looking at it and the current WS bodybuilding catalog, they indicate that it can be modified in frame with no consequences.

It can be preheated and post heated to relieve welding stress. That much I do know.

I think 1ft either way would be a minimum fix. At best I'd like to sleeve the entire drive section to prevent this from happening again any time soon.

Either way, I'll be making a decision tomorrow. I may just end up having a local truck shop do it if they're reasonable enough. They have half the kit there anyways.

 

Thanks for the reply. Called dealer and they suggested the same. Insert forward to the drivers at a minimum. We'll see what our local job shop has to say about it, apparently everything channel related has to be brought in from the US now.