I'm rounding out my 3rd year of owning my 01 hundy. I feel like im pretty good at remediation of rust, removing and replacing bolts etc. The caveat is any frame bolt (mostly 12m head that runs perpendicular to the ground) is a toss up as to whether it will come out or break - regardless of the care and technique. While removing rear bump stops for replacement, the driver side came out but both passenger bolts broke. Drilled the broken bolts but was unsuccessful extracting or re-tapping (m8 1.25). So I drilled out the welded nuts entirely as they were beat. So my question: Are there any recommendations as to self anchoring stainless metric bolts? Will likely go to Fastenal this week but thought I'd ask this forum...
Welded nuts inside frame. (1 Viewer)
- Thread starter eliesh
- Start date
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I ran into this problem which frustrated me to no end.
I don't know about any self tapping bolts but I ended up having the bumper spot welded in a few spots to the frame.
I've pounded the s*** out of that thing while offroading and haven't had any issues. No trouble towing either.
Let us know what you decide to do?
I don't know about any self tapping bolts but I ended up having the bumper spot welded in a few spots to the frame.
I've pounded the s*** out of that thing while offroading and haven't had any issues. No trouble towing either.
Let us know what you decide to do?
JunkCrzr89
Competent Ignoramoose
I busted off the welds of the capture nuts inside the front frame horn for the recovery point. To fix it, I cut out that section of the bottom of the frame, welded the capture nuts back to the plate, and then welded the section back to the frame.
Another, less invasive option is to make a rectangular washer or keeper out of steel plate, drill a hole in it, drop a bolt with a square shoulder through the hole, and then pull the bolt + keeper through the nearest access hole in the frame and into the hole where you need it via high-lbs fishing line or similar. This is what’s commonly done by trailer companies when the capture nut for a trailer hitch mount breaks inside a truck frame.
Another, less invasive option is to make a rectangular washer or keeper out of steel plate, drill a hole in it, drop a bolt with a square shoulder through the hole, and then pull the bolt + keeper through the nearest access hole in the frame and into the hole where you need it via high-lbs fishing line or similar. This is what’s commonly done by trailer companies when the capture nut for a trailer hitch mount breaks inside a truck frame.
Rivnuts are inexpensive and can be installed without special tools, I've got several under my cruiser.
JunkCrzr89
Competent Ignoramoose
Depends on the application, of course, but I agree that rivnuts could be used for some stuff (e.g., skid plates). IIRC the pull-out force of most standard rivnuts is around 400-600 lbf. I have no idea what forces a swaybar mount could exert, but prob not enough to rip out a rivnut.
Both good considerations- riv nut in place of captured nut and load force that could pull them out-
Never put thought to the limit but that should be a primary consideration- ! important post @JunkCrzr89
Never put thought to the limit but that should be a primary consideration- ! important post @JunkCrzr89
On my 99's rear most bumper nuts within the frame I knocked them out and welded new ones in their place. If you have a welder or a friend with a welder and you can get access to the area, that's a pretty good way to fix the problem.
Lot of published information on various types of nutcerts and their load capacities thread strength, shear, upset forces. Often times they exceed a 12.9 grade fasteners. High load incerts for an m8 or even m10 would yield thread strengths of over 10,000 lbs. I'd assume that's enough for a sway bar, I have actually used them before on the rear of a 100 series forthe sway bar.
- Thread starter
- #9
Thanks for the reply. These are the welded bolts (m8/1.25) for the rear bump stops - rubber nubs that protect the rear axle from banging against the frame rail. Long story but had to address (unexpectedly) the APPS (accelerator pedal position sensor). In the meantime I ordered stainless "rivet nuts + tool" from mcmaster carr. It's my July 4 day off project and will let you know how it goes.
Thanks for the reply. These are the welded bolts (m8/1.25)for the rear bump stops - rubber nubs that protect the rear axle from banging against the frame rail. Long story but had to address (unexpectedly) the APPS (accelerator pedal position sensor). In the meantime I ordered stainless "rivet nuts + tool" from mcmaster carr. It's my July 4 day off project and will let you know how it goes.
That's the direction I'm going. Mcmaster Carr.
- Thread starter
- #10
The 8m/1.25 stainless rivnut needs an 11mm opening. I used a 7/16 stepdrill and it worked fine. Torqued stainless bolts to 19ft/lb. Pretty easy. I did buy the install tool rather than using some of the ad hoc methods you see on line (bolts & washers). The tool and 5 riv nuts came to 56 with taxes and shipping.
