How to fix a bent frame rail?

Last week I received a '99 XJ that was hit in the front right directly on the passenger frame rail behind the bumper. The frame rail looks to be pushed back a bit as the passenger motor mount is misaligned. I plan on using the drivetrain and interior for my '88 MJ project, but that truck isn't anywhere near ready for the transplant so in the meantime, I'd like to get the '99 XJ back in commission.

Obviously, the right way to do this is to take the truck to a body shop with a frame straightener/puller, but I'm afraid of what that would cost and since I plan on stripping the thing down to the shell, I'd rather not invest too much money into it.

So, I've heard some pretty interesting stories in the past of people fixing bent frames using a heavy duty chain and a tree and I thought I would throw the question out there to see if anyone else has any clever ideas. I have a set of tow hooks on my MJ - the kind that bolt directly to the frame rail and I was thinking of maybe sacrificing one of those for the cause. I could always build another if I break it.

So, does anyone have any good backyard mechanic tips they'd like to share? My biggest concern is that if I jolt the car enough, I'll set off the airbags! I should probably do some research on how to disable those!

Ha, I see no one wants to touch this topic! Here are some pictures I snapped of the damage.

Does the passengers side door still line up and shut ok? Id bolt some plates to the rail, one on each side and pull it from them. The rails are usually easy to get back in shape. A friend of mine has rebuilt several XJs with little effort. Best way is to chain it down like if you were hauling it. Chain it down however possible, both axles, rear hitch, any place you can get a hook in it. A porta power is the best way to pull it if you can borrow or rent one but if not a come along works wonders. The chain ones are alot better and safer than the cable. However you do it just be safe!

Disturbedxj said:

Does the passengers side door still line up and shut ok? Id bolt some plates to the rail, one on each side and pull it from them. The rails are usually easy to get back in shape. A friend of mine has rebuilt several XJs with little effort. Best way is to chain it down like if you were hauling it. Chain it down however possible, both axles, rear hitch, any place you can get a hook in it. A porta power is the best way to pull it if you can borrow or rent one but if not a come along works wonders. The chain ones are alot better and safer than the cable. However you do it just be safe!

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The passenger door lines up and shuts just fine. The frame isn't badly damage...just maybe pushed back a little bit - enough to have moved the motor mount.

I understand your methodology of strapping the truck down and using a porta power to muscle the frame back into shape, but I'm trying to think of what the heck I can strap the truck to that would hold. Guess I need to find two trees, now...one to anchor the truck and one to anchor the porta power or come along!

Do you have a car trailer?

browncountyxj said:

Do you have a car trailer?

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Yes, I do. But following Newton's third law - whatever force I exert on the frame to straighten it out (via a porta power or come-along), I will be applying and equal, but opposite, force on whatever I attach the other end of the porta power/come-along to. If I were using my car trailer, I would strap it down as I normally do, and then attach the porta power/come-along to one of the rails on the trailer...that certainly would not hold!

We anchored a hook to the floor in our old shop. Use big (5/8 or so) drill in hardware store anchors and a piece of 1/4" steel with a hook or loop on it.

I would think twice about using an anchor on the floor, seems like it'd bow the ends of the frame rail down from the downward force instead of pulling it straight out. Maybe a triangulated frame to pull against, anchored into the floor?

Sounds like I need to find two really big oak trees just the right distance apart

If the trailer you have is built heavy just chain it down to it and pull from it as well. may take some rigging but youll get it. The two tree method works too just be careful.

I wouldn't think pulling from the front frame horn, while having the rear bumper attached to anything would be a good idea. No telling what "tweaks" you would introduce else where in the frame.
Seams to me you need to somehow attache to the frame, just behind the motor mount, in order to isolate the correcting forces to the damage area.

xjbubba said:

I wouldn't think pulling from the front frame horn, while having the rear bumper attached to anything would be a good idea. No telling what "tweaks" you would introduce else where in the frame.
Seams to me you need to somehow attache to the frame, just behind the motor mount, in order to isolate the correcting forces to the damage area.

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Yes, to do this right, that's what would need to be done. I'm really just looking for a quick-fix since in a few months time I'm going to be stripping this truck down to the shell and using all of its parts for my MJ project. However, in that time, it'd be nice to use it as a spare in case my current daily driver ('01 XJ) goes down. I have a TON of driving to do starting in January so it'd be nice to have a backup.