Pintle bolt hole size on 80's

[Schattenjager]

Anyone know the bolt hole size for this? I tried the bolts that came with the hitch but they are standard, course theads etc. and won't thread past two turns.

 

[94SRUNNER]

M12 x 1.25 x 60mm

Remember to ask for grade 8 bolts.

Since the 2 lower holes doesn't have a thread I suggest you to add a
(inside the cross member) reinforcing steel plate as wide as possible,
with the 2 holes pattern pre-drilled and if you can, weld the nuts on
it, before inserting the plate. This will help you to install the
bolts with only one wrench. Don't forget to torque the bolts to at
least 80 lbs and you should use one flat and one pressure washer for
each of the 4 bolts.

It's a cheap and easy way to reinforce the cross member and limit
somewhat it's flexing if you pull a trailer with some tongue weight.

 

[Schattenjager]

Any chance it could be M12 1.75 x 60mm?

 

[94SRUNNER]

I double checked on Mud

http://forum.ih8mud.com/263260-post10.html

http://forum.ih8mud.com/4178294-post51.html

You got me thinking so I had to go and dig it up, but M12 X 1.25 are what you need for the top two holes.

 

[MoGas]

M12 x 1.25 x 60mm

Remember to ask for grade 8 bolts.

Since the 2 lower holes doesn't have a thread I suggest you to add a
(inside the cross member) reinforcing steel plate as wide as possible,
with the 2 holes pattern pre-drilled and if you can, weld the nuts on
it, before inserting the plate. This will help you to install the
bolts with only one wrench. Don't forget to torque the bolts to at
least 80 lbs and you should use one flat and one pressure washer for
each of the 4 bolts.

It's a cheap and easy way to reinforce the cross member and limit
somewhat it's flexing if you pull a trailer with some tongue weight.

A) Metric hardware isn't graded in the SAE grade 5 or grade 8, etc. You want to find a grade 10.9 alloy steel quenched, tempered, and zinc plated fully threaded hex bolt. I got mine at my local NAPA.

B) there is much debate about the strength of the rear cross member. In the UAE, they are rated to tow up to 3500Kg (~7700 lb.) The frame is the same part number as a US frame. I regularly tow all sorts of things from my pintle. I have yet to see any evidence of fatigue or stress. I even performed a dye penetrant NDI inspection on the cross member welds, just to be sure.

Here is my setup:

Dave

 

[MoGas]

And Don, They are M12 x 1.25 x 60mm.

 

[ntsqd]

I wouldn't go with fully threaded unless the unthreaded shank is too long in that length bolt. Is it?

Also suggest actually torquing those bolts to spec with Locktite in the threads.

 

[MoGas]

I wouldn't go with fully threaded unless the unthreaded shank is too long in that length bolt. Is it?

Also suggest actually torquing those bolts to spec with Locktite in the threads.

If I recall, that was the case.

The reason I have my bottom bolts with the nut end out is so I can quickly identify if the nut is working loose, and, when you have a nut and bolt, you should torque the nut. It is far easier to access the outside of the cross member with a torque wrench than the inside. I did not use a thread retaining chemical and, when I do my annual inspection on my rig, the nuts and bolts have never moved during re-torque according to my notes.


Dave

 

[ntsqd]

Hadn't noticed your exposed nuts.

Consider a witness paint stripe, or more concerned with bolt stretch than with loosening?

 

[JJackson]

I even performed a dye penetrant NDI inspection on the cross member welds, just to be sure.

What do you do when you're bored Dave?

 

[MoGas]

What do you do when you're bored Dave?

Whatever the voices tell me to do, Jamie, whatever they tell me.....




Dave