Bolt Size front bumper

[scheinerj]

I am cutting/ repairing the front frame section due to a non original front bumper being installed. Do you know the size of the bolt that should be used for the bumper gussets, and the bumper installation?

I do not want to use rivets.

Thanks!
js

[Michael O.]

JS...the bumper gussets didn't use bolts, therefor, I cannot give you a size. You can get sheer bolts with a rivet type head from Brent Mullins (I believe). They look good and are a decent substitute for the gusset rivets. Off the top of my head the bumper bolts should be 4.5 X 5/16 UNC

[Capt. Peacock]

I’m a little confused, I was just about to take the bolts out of my Bumper gussets to replace them with rivets when I noticed this picture in TM 9-803. It clearly shows the gusset plate held on with hex bolts.

[JAB]

Field repair probably.

[nick peters]

Artistic licence
regards Nick

[Bill H.]

3/8 NF grade 5, 3/4" long works. Chuck the bolt in a drill and while the drill is running use a bench grinder to round the head of the bolt to look like a rivet. You can then install the bolt, head out nut in frame hidden. Lots have been done this way and you can't tell by looking unless you get right down and look up into the frame.

[Bill H.]

I’m a little confused, I was just about to take the bolts out of my Bumper gussets to replace them with rivets when I noticed this picture in TM 9-803. It clearly shows the gusset plate held on with hex bolts.

This has been a point of discussion many many times here over the years. There really isn't any real or good explanation for it but the originals were riveted.

[dpcd67]

Since I have no way to install proper rivets, I lathe turn the heads off grade 8 (overkill) bolts to match either MB or GPW rivets. No one but a G503 member will ever know....
I once used the break off rivet/bolts too.

[Capt. Peacock]

Thanks Bill.