Warped/Bent/Bowed Rear Bumper

[JimVG]

I am experiencing problems with finding a new rear chrome bumper without impact strip for a 1978 K20.

I am attempting to find a new bumper that is straight and level along the top, and devoid of any bends/warps and/or misshaped areas.

I have purchased and returned (2) new bumpers; one from Holley/Brothers Truck Parts and the other from LMC Truck. They are listed as “Premium”. Both bumpers came in the exact same box & packaging from the same Taiwan manufacturer, and had the same defect. They were both significantly warped/bowed at the top; high in the middle and 1-1/2” low on the ends.

This defect results in the top of the bumper being not parallel with the trim molding at the bottom of the tailgate. The gap between the top of the bumper and the trim molding should be straight, level, and consistent when installed. I know that the factory bumpers do not have this issue.

Does anyone here know of a manufacturer that has a product that is not misformed?

Any information/advice would be appreciated!

Thanks.

 

[Finkaire]

We have bumper restorer’s near us. They straighten and rechrome. Check your yellow pages. OE is always better

 

[1STLS1]

I see it's mounted to the vehicle, any chance the center brackets are pulling it in causing the top to bow out?

If it was me, using a block of wood and a heavy hammer would not be out of the question to move the top of it around to make it fit better

 

[JimVG]

I was able to correct most of the warp by manipulating combinations of the mounting bolts and brackets, and systematically ”adjusting” the shape of the bumper with a floor jack while the bumper was mounted on the truck. The metal is thin enough to allow cold forming in this manner. Worked for me!

As most of these bumpers seem to have this problem, I hope this method can be used to help others.

Thanks for the reply’s!

 

[1STLS1]

When working on trucks 30-40 years old that spent their first life as a truck, it's a challenge to bring them back to the way they left the factory. That bump in the front or rear when the truck was 10 years old and not worth much is an issue now because the rail or bracket is bent to tweaked and you didn't see it..