REAR Bumper guard Lower Bolt

[R/T4ME]

I am trying to figure out what size and Theard bolt is used in the bottom of the rear bumper guard for 1970 Challenger shown below.

It is the bolt that connects to the frame bracket, it is close to a 5/16 X 18 but that will not work.

I am thinking it must be a special bolt.

Matt

 

[MOPARMITCH]

I am trying to figure out what size and Theard bolt is used in the bottom of the rear bumper guard for 1970 Challenger shown below.

It is the bolt that connects to the frame bracket, it is close to a 5/16 X 18 but that will not work.

I am thinking it must be a special bolt.

Matt

View attachment 151807

View attachment 151808

It shouldn't be a special bolt. It is probably 5/16 or 3/8. The captured nut in the unit may be stripped or the threads may be gawled

 

[6PKRTSE]

Pretry sure mine were 5/16-18.

 

[Vaanth]

I am trying to figure out what size and Theard bolt is used in the bottom of the rear bumper guard for 1970 Challenger shown below.

It is the bolt that connects to the frame bracket, it is close to a 5/16 X 18 but that will not work.

I am thinking it must be a special bolt.

Matt

View attachment 151807

View attachment 151808

The rear bumper guard lower attachment bolt is a 5/16-18 with a 1/2" hex head.

 

[Xcudame]

See attached page from the MCC Guide to E Body Fasteners.

 

[pschlosser]

I am trying to figure out what size and Theard bolt is used in the bottom of the rear bumper guard for 1970 Challenger shown below.

It is the bolt that connects to the frame bracket, it is close to a 5/16 X 18 but that will not work.

I am thinking it must be a special bolt.

Matt

Hey Matt, I'm not far from you in Santa Rosa. I can sometimes overthink stuff, and I encourage you to not overthink this. You are not going to find mysterious "difficult to distinguish" bolt and thread sizes on these older Mopars.

Take your part to your local ACE hardware or Home Depot hardware retail stores. They have this bolt guide you can use to determine the bolt diameter and thread count of your desired part, often visually just by closely comparing your threads to the guide.

Sometimes, on these older parts, that are rusty, you start to screw in a bolt and it gets tight, leading us to think we got the threads wrong, or something.

It looks like you don't post very often, so please let us know how it's going and if we can be of help.

 

[terrywalker]

I agree it's a 5/16" -18 bolt. Run a 5/16"-18 tap, using a tapping fluid, in there to clean it up. If it's galled, you don't need a broken tap in there.
Terry W.