Radius Arm bolt hole's stripped? What's the fix?

[needabronco]

I finally sucked it up and started the install of my suspension system today. Everything was going well until I cross threaded one of the bolt holes on my extended radius arms. I ran a tap through it and cleaned it up, but the next bolt did the same thing. Before I completely trash the hole, whats the fix? Can I helicoil the hole? I though of welding up the hole and starting over but that seems near imposible... I'm not sure there's enough thread left to clean up again and see if it will hold.

 

[Project_bronco]

OK, this might not be the best thing to do, it's just a thought I had...what about drilling out the threads, sticking the bolt through, and putting a locking nut on the end of it like a nylock? It won't look like the other three holes, but it will probably get you down the road. You may need some washers (a locking washer wouldn't hurt).
Or, take it to a shop or buy a used one.
Sorry I couldn't be any more help.

 

[broncnaz]

The longer bolt idea will get you by but I'd just get some replacement arms any pre 80 ford truck or BB tap all the threads before assembling it will help.
Helicoils would work but for the price Id just get some new/old replacements.

 

[ManTruck]

Give a thought to going up to the next size bolt. Drill all associated parts, arm and cap, and tap to a larger size. Buy an appropriate hardened bolt and drill to fit.

 

[76MaBronco]

I'd go next size up or a heli-coil over welding a stud to the arm. I say that as the mating surfaces touch, and if you have any slag on those surfaces your caps won't sit right.

 

[70_Steve]

Don't know what the permenant fix is, cause I (you) don't yet know how badly the threads are damaged. But there's a couple things I'd suggest.

Don't attempt any repair with the radius arm mounted up to the differential. You'll never get anything straight.

If you're drilling, tapping or trying to start the bolt, have the c-cap bolted up solid with the other bolt, and use the hole in the c-cap as a guide.

You might try running the bolt, or tap, in from the rear of the hole. The bolt holes are tapped all the way through.

If the threads are too damaged to recover, use a helicoil.

 

[Broncobowsher]

Just replace the arm. Thy are easy to find. I have a spare pair sitting in the garage. If I was heading toward Prescott anytime soon I would just give you one of them (I need to keep one for another project).

 

[needabronco]

I plated the back side of the arm so you can't go in from the back. I'm going to try one more idea and then they are coming off and getting a helicoil.

 

[Broncobowsher]

Missed that plated and extended part, that makes it a bit tougher.

 

[Dave]

Maybe you could drill it up a size and retap. Perhaps a metric would be a good step up in size.

 

[KyleQ]

Nothing wrong with running a bolt and a nut - lot easier to get the arms back together as well. Grade 8 with a grade 8 nylock nut and you are good to go - never had any problems even running 38's with a 400 in a big Bronco.

 

[needabronco]

Working on finding a helicoil that big, NAPA has a kit but their price is $89, and the helicoil itself is $1.10 at the hardware store.... Hopefully I'll get it apart today and see if a machine shop has one. We'll see.

 

[70_Steve]

McMasterCarr has the individual taps, sets of 5 inserts and the install tool. I bet you could make your own install tool and save that money. I also checked WW Grainger ('cause there local here in Phoenix) but they're way high on price! 9/16-12 right?

 

[needabronco]

1/2" helicoil kits here in town are $23.99, but step up to 9/16"s and I'm looking at $89. I'm having a local machine shop do 2 holes for $30, I'll pick the arm up tommorrow morning...

 

[DonaldDouchebag]

Maybe you could drill it up a size and retap. Perhaps a metric would be a good step up in size.

I did the same thing years ago. Works perfectly.

 

[KyleQ]

What is the fear against just drilling the threads out and using a grade a nut and bolt? Less hassle, easier assembly and disassembly and is the most cost affective.

 

[needabronco]

Installed 2 helicoils this morning and everything is back together. I love the new stance...