Bullbar chassis captive nuts

ShortyNavros · Apr 9, 2015

Hey guys,

I took my bullbar off today and yesterday to give the front chassis rails some rust treatment and fresh paint.

When re-installing two of the 4 captive chassis nuts (2 per side, square nuts welded to the inside of the chassis) are now not torquing up, I can remove the bolt and the bolt is fine I must have stripped the nut in the chassis..... Is there anyway to fix this?

There is one nut stripped either side, so one on each side is still good, the stripped nuts still have the bolts in but they arent what I would call done up tight, but they are as tight as I can get them.

Has anyone else had this problem? I didnt even really torque them than tightly and they let go quite easily, the bolts are grade 8.8 hardware so maybe the chassis captive nuts arent that higher tensile, however being in the chassis on a standard vehicle you think they would be as they are a pain to replace (if replacing them is even at all possible?!)

Any help would be wonderful, I have an stock alloy bar.

Cheers,
Short

ben85 · Apr 9, 2015

i stripped one a while back.

i think they're m10 fine thread.

i re-tapped the nut with an m12x1.25 thread and used a bigger bolt.

ShortyNavros · Apr 9, 2015

Cool so I just have to buy a tap, think I only have an M8 Tap, did you do all of them? or just the ones you buggered up? So I take it these welded nuts arent the most high tensile nut going round

04HUG · Apr 9, 2015

G'day
It should be an easy fix if you get a "Heli-Coil" kit from a Bolt/Fastener Shop.

atcmatt · Apr 9, 2015

Definitely Helicoil it. Stainless threads, mint.

ShortyNavros · May 4, 2015

The nuts that no longer tighten have already been heli coiled as when I pulled the bolt out after it wouldn't torque up the heli coil came out with the bolt. Would re doing the heli coil work? As obviously the last heli coil didn't work overly well

atcmatt · May 4, 2015

I have never had a problem. As Long as you drill straight, and use the right size bit and tap, there is no reason it should pull out. Obviously has not been done properly, however most of my experience with them is into aluminium and not steel.