Looking for some advice on how to straighten the drivers side rear frame rail. It sits about 3/4" lower than the p***enger side measured at the very end. I have gone thru and measured and checked various points on the frame and suspension both front and rear. I verified tire pressure and confirmed the leaf springs are the same left to right by matching them up and even swapping them side for side. The last check was to use a rigid straight edge resting on the top of each frame rail to take measurements. The drivers side drops the 3/4" in the last 20". I think the truck might have gotten hit at some point as there are some holes in the frame back there that are bent out a bit. Here are some pictures of what it looks like and you cant really tell from the pictures the amount its off by. The last picture is my thoughts to jack it up. Both the jack and chains are just there to represent my idea and not the actual ones I would be using. I have the rear crossmember out thinking it might be pulling it down and figured it would be best to leave it out until I get the frame lifted and then make sure it fits correctly.
If you have access to to tie down pots its easy. Just tie it down and jack it up. If not, then your idea seems pretty good. Dont be afraid to make a cut to relieve stress, and weld it up when its straight.
I dont have any tie down pots. Was thinking of maybe trying to tie it to the 2 post lift mast but afraid of bending it somehow....
That looks like it would work. K. I. S. S. One thing we do when we want to straighten big frames at work is to set up a transit. Shoot in the main portion of frame level and leave the transit set up. Helps keep track of where you are going and how much it will take and helps with changing up things easier. Less times for a level to be off from one use to the next. Be aware that if you go this route and decide to shoot in other portions of the frame, you may find other things off and chasing a rabbit down a rabbit hole can be frustrating.
It appears your frame has been ‘C’d”. Did you perform that mod or have it done or bought it that way? Ideally, you would set the frame on a level surface, put it on four jack stands (alike on forward position and same on rear. If you don’t have four alike stands, use two pair, matched on the forward position and matched on rear position. Using a level, check side to side for “level” both front and rear. Add shims to the forward stands to level the forward frame rails. At that point, if in fact your frame is only bent in the rear section on one side, it should become obvious which rail is bent down where and by how much. Cold bending would be the best method to straighten the rail. Jack the rail past the point you want it, use a bfh to hammer on the frame in the area of the bend to relieve stress. You may have to repeat this process a few times but it should come into alignment. If here is an obvious ‘kink’ in the frame rail, and repeated attempts to cold bend do not produce results, you ‘could’ heat the stubborn section while under tension. In no case would I recommend cutting the rail and welding it back together. p.s. I forgot to address the ‘C’ modification. It could very well be that is where the misalignment is occurring. Or not. But if it should prove to be, then correct that, of course. Is the reinforcement bolted in, without welds, or a combination of bolts and welds? If only bolted, loosen the bolts, or remove them if they are very tight fitting. If the latter, jack the frame rail into place and drill the misplaced holes and snugly refit larger diameter bolts where needed. Best Wishes, Ray
Attempting to pull up the tail of the frame as pictured will only result in depressing the area underneath the jack and twisting the frame, floor pots at a minimum or a frame straightening table would be best, you need to stabilize and isolate the area to be repaired or risk creating problems elsewhere
I worked on it a bit last night and decided to take the slow think about it approach. I did find that it wanted to push down on the top of the frame rail and pulled the frame in a twisting motion. So I moved the jack so that it was centered over the vertical part of the frame. Next I tried multiple placements of the chain in the way it wrapped around the frame so that it was pulling more evenly and no twisting it. I had some success in got it raised by about a 1/4" without causing any more problems. There is no visual evidence of a bend in the frame. I am going to try and move everything a little further back and see if I can tweak it over a few different areas instead of just one. I wish I had some anchor point on the floor as I think that would be a better way to do it.
If you have a heavy beam available that’s approximately 3/4 the length of the frame or better, would also work
That’s a question I have asked myself several times without a great answer. I know for sure that they are not even and the difference is in the rear frame rails. The drivers side has some bolt holes that are deformed like something twisted them so I chose that side to work on. I forgot to add that I used 2 pieces of heavy aluminum angle clamped to the frame rails at the same locations and verified that they where both level side to side and measured even to the ground at the ends. Then I measured from the bottom of those to the top of the frame rails to determine for sure that the rails are different from drivers side to p***enger side.
Instead of a level, get yourself a laser level ($20 and up). It will shoot a line across a wide area. Just measure down from the projected line to the frame. Quick and easy to tell where things aren't right. You can also measure what is moving, and how much, when making adjustments. Get some shingle shims to do the fine leveling when setting up the frame. By sliding a pair of them together you get infinite adjustment.
I made it happen somehow. It took longer than expected but I managed to get it within a 1/16". I also found that the rail was slightly bent out as well. I used a come along diagonally to pull it back. I spent some time measuring and pulling to get it as close as I could. Luckily there are some holes and rivets on the top of the frame that I could measure diagonally to verify it was square.
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