Should I Grind Bumper so Bolts will fit?

[Ogre]

Hey,

So I ordered some new chrome bumpers for my '72 Challenger from AMD. They came with new bolts and nuts but I can't get the bolts to fit in the holes. My first thought was to just grind on the holes until the bolts fit but I stopped myself because I was afraid it might cause the chrome to flake off in the future.

Any thoughts? Can I just grind them out and paint the edges?

Thanks.

[dutch]

they might have drilled the holes to fit and with plating on bumper and bolts together the fit is too tight...?  Id measure how much you really need and rather turn / file the bolts down to the size you need.

[Ogre]

have you tried loosening the bumper mounting bracket from the frame? There are holes there that might be elongated & not have to mess with the bumper.   

I have the brackets off of the car. The problem I'm having is that the SS bolts won't fit through the square hole in the bumper.

they might have drilled the holes to fit and with plating on bumper and bolts together the fit is too tight...?  Id measure how much you really need and rather turn / file the bolts down to the size you need.

That's not a bad idea. Can I file them down without messing up the threads?

I've also thought about getting different bolts, maybe it's a metric SAE thing.

[72rtchallenger]

I would contact were you bought the bumpers at and ask them , maybe they sent improper bolts or can send some that would work

[YellowThumper]

I would contact were you bought the bumpers at and ask them , maybe they sent improper bolts or can send some that would work

/\this/\
Right now if you need to bumper can be returned.
If you grind holes it is yours. I personally would be concerned with grinding them.
If you have calipers or access to some. Check hole size AND check bolt diameters. I have seen them oversized befor. Bolts should measure undersize to nominal diameter. And bumper holes should measure over nominal.
Don't recall what sizes they are.

[blown motor]

Keep us posted on the outcome of this please. I'll be in the market for new bumpers this winter and if AMD is having issues I don't want to go there.

[anlauto]

Grind the bolts not the bumper Try buying different bolts

[roadman5312]

Are you saying the square part of the bolt under the head won't fit the square opening ? Or the threaded part won't even go in the square opening ?   

[Katfish]

Grind the bolts not the bumper Try buying different bolts

My thoughts exactly, easy to grind the square part of the bolt till it fits the bumper opening.
If you screw up, no biggie, get another bolt.
Grinding the bumper will promote lifting/blueing of the chrome.

[roadman5312]

Are you saying the square part of the bolt under the head won't fit the square opening ? Or the threaded part won't even go in the square opening ?   

                 We don't even know the answer to this question yet, has not been verified. If he was sent 7/16- 14 versus 3/8-16 that could be the problem. Could be simple wrong carriage bolts, don't want him grinding threads/bumper/   

                                                                                       

[Denison636]

I agree roadman5312. I just put a rear bumper on my car and I just went up to Home Depot and got bolts for mine. Same bolt and I got stainless steel ones a lot cheaper there to. The markings polish off to look like chrome.

[Ogre]

I ended up just going to the hardware store and getting some 3/8" carriage bolts which seem to work for now. They're a little loose but they hold, the 7/16 they sent me the threads wouldn't even pass through the square holes. I'll try to find somewhere that sells polished SS or chrome carriage bolts in 3/8 in the future and snug them up a bit more.

[roadman5312]

I ended up just going to the hardware store and getting some 3/8" carriage bolts which seem to work for now. They're a little loose but they hold, the 7/16 they sent me the threads wouldn't even pass through the square holes. I'll try to find somewhere that sells polished SS or chrome carriage bolts in 3/8 in the future and snug them up a bit more.

                                                                              

[anlauto]

There's your problem.....Bumper bolts are supposed to be 3/8 not 7/16

[70chall440]

There's your problem.....Bumper bolts are supposed to be 3/8 not 7/16

  absolutely correct, you got the wrong bolts with your bumper. I just replaced both bumpers on my Challenger and spent the last 2 weeks working on the rear bumper of my Cuda and I am 100% positive they are 3/8 and not 7/16.