Stuck Frame Bolts

[Oski1868]

I would have thought this might have come up in the past .. . (I searched "stuck frame bolts" but didn't come up with any hits)

Have any of you come up with a solution (short of cutting them off) to removing frame bolts on your FMTV? I have to believe they were assembled with a large hi-torque machine. My supposition is that I will need something similar to get them off in one piece ...

Already broken a couple of wrenches with gorilla bar attached.

Cutting actually works fine ... I just wondered if there were any tricks out there.

 

[NDT]

I have not needed to disassemble my LMTV, but I know the frame attachment fasteners on the M915 truck takes a 3/4 drive impact wrench to loosen.

 

[Suprman]

Those are strange looking I wonder if they have to be impacted from the bolt side.

 

[NDT]

Those are strange looking I wonder if they have to be impacted from the bolt side.

I don't think so Suprman, I recall the factory having a huge torque gun hanging from a balancer at the frame assy station, with the employees handling it from outside the frame.

 

[tim292stro]

First off - those aren't regular bolts.... They are the modern cold-rivet style used by all heavy truck manufacturers called "Huck Bolts". The thing you think is a nut was a nut finger tight and then was swaged onto the bolt to prevent it from backing off, and to pull the material tight (just like what would happen with a cooling rivet contracting).
https://www.youtube.com/watch?v=4f9BDIST4GM

They can be removed by cutting the "nut", but you need a tool to do that, and a tool to re-apply the new Huck Bolt and nut. I'll never say it can't be done (those who say that just haven't thought it through ).

 

[Lmtv772]

Right I was just gonna say 'huck bolts' they are impossible to get off. I cut off the protruding part of the bolt with an angle grinder, to make it flush with the 'nut' , then cut the center of the bolt and nut right down to the frame so all i had to do was give the cut in half nut a whack and it dropped off. Then the bolt fell right out. (hope my description made sense)

 

[tim292stro]

The are supposed to be difficult to remove (you gotta really want to!!) - they hold on the suspension and hold the frame together on a 40k-lbs truck... I wouldn't want them to have to be checked after production ever, that would be a nightmare for heavy truck maintenance.

 

[Plane Fast]

Huck bolt! For the life of me I could not remember. Yes you have to cut them.

 

[aheilmann68]

Huck bolt. Had a 1" gun strip one off to see if it was even possible. Highly do not recommend, cut off with a cut off disk or a torch and replace with grade 8 and torque

 

[quickfarms]

Torch removes them quick

 

[tim292stro]

They are intended to be cut (my post above had instructions in the "tool for removal" link). This is the full training video for the Huck tool:
https://www.youtube.com/watch?v=9l8CjIBc-30

The version you see on your trucks is the one where the tail piece shears off at correct swage pressure/travel - this isn't as precise or serviceable as the version where the tail-piece stays attached.

 

[Oski1868]

They are intended to be cut (my post above had instructions in the "tool for removal" link). This is the full training video for the Huck tool:
https://www.youtube.com/watch?v=9l8CjIBc-30

The version you see on your trucks is the one where the tail piece shears off at correct swage pressure/travel - this isn't as precise or serviceable as the version where the tail-piece stays attached.

I was afraid this was a dumb question ... always learn something from you guys! Thanks!

 

[Oxyacetylene]

Thanks for the information on the bolts. I will echo what the others have said that they are near impossible to remove by loosening them. I tried a 24" breaker bar on a couple of them. One came loose and the other didn't. I tried a 1" impact wrench..a couple came off and others didn't. When you try and loosen them, there is about a 50/50 chance that it will pull the threads loose, which cause the nut portion to jam. My reason for trying to remove them was to take the upper frame section from an M1079 and replace it onto my frame to create an M1079 and still have the winch. After counting up all the bolts to be removed and their locations, I decided against that...