Bot size for M-37 threaded holes?

[dcbrown]

I have been struggling with finding the proper size bolt for screwing into the threaded holes found in various spots on my M-37. I'm trying to install a jump seat right now, but bolts seem either a hair too big for the pre-threaded mounting holes, or they are too small. Can anyone confirm the correct diameter of the bolts for me? Thanks a ton.
Chris

 

[M543A2]

It is not easy to answer because there are several sizes of bolts used, depending on application and where.
All of the bolts on mine are SAE sizes, no metric. They are probably 5/16, 3/8, 1/2 inch and so on. Be sure the threads are clear so the bolt can thread in. Check to see if they are fine thread or coarse thread. Many times if a hole has not had a bolt in it for years, you need to take a tap and clean out the threads before a bolt will fit. You might buy or look at one each of the above bolt diameters in both coarse and fine thread for your trials and reference if you are not familiar enough with the different threads to recognize them when you look inside a nut or at a bolt.
That is the best I can tell you at the moment without being there to look myself.

Regards Marti

 

[dcbrown]

Marti gave me a hand. I just re-tapped the threads and 3/8 bolts slid in perfectly. Problem solved. Thanks Marti!!!

 

[Nickathome]

Alot of the bolts on these trucks are NF (national Fine) threads. Find a local mom and pop hardware store to deal with these types of bolts. For if you go to Lowes or Home Depot and ask the clerk for a fine threaded bolt, you will get the Deer in the headlights response from the idiots who work there.