Rear bumper question

[MustangChuck 16]

About 4 years ago, I pulled the rear bumper and leaned it in a corner of the garage. (Yes, progress is slow.) I just got the car back from the body shop on Wednesday and they had put the bumper back on for me. There is a noticeable bow in it that I don't recall seeing before. The rear was a little messed up and the bumper may not have been properly aligned before. Would standing it on end for a few years cause it to bend?

 

I fear that the body shop put the tail light panel in wrong. This would cause the bumper to stick out farther from the mounting tabs in the trunk, making the bow more noticeable since the top of the curved area is now hitting the panel.

 

How much gap should there be between the bumper mounting tabs and the tail light panel?

 

Here's a picture of the bumper installed. There appears to be quite a gap at each end (the same amount of gap is on the driver's side).

 

Thanks,

M/C

[SELLERSRODSHOP 13]

chances are, your car had light bump in the rear at some time that tweaked the bumper & tailight panel. the new tailight panel magnifies the bumper & its bow. time for a new bumper....

[Cruzzar 22]

I just checked my '70s bumper (same as 69). I put a straight edge on the bumper from one side to the other, (from the area right before it curves to go around the quarter extension) and measured right in the middle and found that the bumper is about 1/2" further away. I other words, the bumper does curve across the back. It is curved out away from the car in the middle. This allows room for the license plate light to fit between the body and the bumper. I hops this is clear and helps.

From the picture it appears that your bumper is curved in toward the body and not away.

Standing on it's end would not bend it.

[RogerC 136]

Taillight panel, trunk lid & bumper should have a slight outward (convex) curve.

[MustangChuck 16]

Yes, this bumper bows inward, towards the body. By a good bit. The car did have a mild hit early in life. There is evidence of it under the back seat on the passenger's side as well as in the frame at the top of the rear passenger wheelwell. I know the tail light panel had been replaced once before (and had enough time to completely rust away).

 

So, new bumper time, eh?

 

Thanks, all! I really appreciate it!

 

M/C

[SELLERSRODSHOP 13]

yeah, mine is the same way. not really noticeable unless you catch it just right. i think whenever the bumper gets tweaked, it pulls the tail panel the same way. add one or the other new, & the old really stands out..

[JayEstes 173]

If that bumper is otherwise acceptable in your eyes, it might be possible to take it off, put it in a large support or otherwise really solid base such as some concrete supports and "rebending" it to remove or reverse the curve. Think like using your hydraulic jack to push near the center while the ends are restrained. You will of course have to be careful how you hold and apply the pressure. But, the bumper is long enough you should be able to apply enough force to bend it. Anyway, just thoughts. If you are down for buying a new one anyway and have some time to play it might work. I'd make some measurements before starting and continually check it in between application of bending loads.

 

Another choice might be to leave it in place, and use a come-along anchored to a solid base to pull the bumper near the center. I'd try to put a block of wood behind the bumper to protect the edges. You just need to be able to apply the forces gradually.

 

You might even call a bodyshop to see if they can manage something like that.

Edited April 23, 2012 by JayEstes

[DRASTiK 22]

I've done similar things to what JayEstes is suggesting on wrecked racecars, but with the cost of a new bumper being what it is today, I'd probably just buy a new one if I was in your shoes. If a new bumper was extremely costly, then I'd try to unbend it off of the car.

 

Also, I don't recommend trying to unbend it while it's still on the car. That may cause you to bend your new tail panel with the bumper.

[MustangChuck 16]

I would definitely not unbend it while it was on the car. I would be more afraid of damaging/destroying the bumper mounts. Those aren't in what I would call great condition. Neither is the floor where they attach. Both are now better, thanks to the body shop, but still not perfect.

 

I was thinking about setting it on the garage floor and putting some weight on the center of it. I was thinking, it's already broken. I can't mess it up more. The bumper itself appears to be in great shape, just a little bent. If I end up bending it in the wrong direction, then I still need to buy a new one. I really don't have much to loose.

 

M/C

[JayEstes 173]

Yes - good advice. I went and looked at how it is mounted, and I retract my previous advice to pull while on the car. The front bumpers bolt up to nice strong frame up front, and for whatever reason I was thinking these did too - but they dont. They mount to that tail light panel. Now, there is a welded stiffener right between the bolts that stiffens this area, but it sure looks insufficient for what we are talking about here. This area is one of the more rust prone areas too, so if you have any rust there that makes that idea a bad one. So- thanks to Drastik for setting me straight. I'll chalk it up to "brainstorming from the couch" (without really thinking it through and checking it first).

 

But, in my opinion, setting weight on while it is on the floor is probably NOT going to do anything. To get the bend out, you have to get the material to yield slightly, which means pulling it a little past the position you want, and then when released, the elastic (reversible) bend relaxes to leave the bumper in the final position you want.

 

Anyway- good luck, let us know how you close it out.

 

Jay