Radius arm woes

Well, the right side radius arm came off pretty easily. And the bushings didn’t look terrible.

So I thought, cool, left one now, piece of cake. Well, not only was the rubber completely shot, but my bolt snapped off. I’ve sprayed a lot of PB blaster on it, but not sure the smartest way to get that rusted stud out? Channel lock pliers won’t work. I was able to turn the bolt good 1/2" out before it snapped. Got harder and harder to turn.

Others have fixed similar issues by drilling the bolt out and then continuing to drill all the way up through the floor. Coming from inside, enlarge the hole in the floor enough to enable you to reinstall the trailing arm with a bolt and a nut.

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Why can’t I just get it out and use new bolt?

You can if you manage to leave the threads in good enough shape that you’d trust them with your life.

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I will let PB blaster soak, and try some vice grips later today. Will drill out/mount in floor as last resort.
I assume the bolt is softer metal than threads?

I’d take a die and clean up the threads enough to put two nuts on. Sort of like a replacement head that you can use to unscrew it.

I’m betting you broke it because you were holding the wrench or ratchet at a funny angle.

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You may have to try soaking it with something like Kroil and using an Easyout to get that bolt out.

BTW, you can access the other end that bolt from above. You may have to remove the rear seat bottom and pull back some carpeting, but there is an opening in the floor with access to the top of that bolt. Maybe working from above and below might be easier?

I have had difficulty getting those radius arm bolts out but I have never broken one off in place.

Good luck.

BTW, I probably have some off those bolts from my parts cars in case you are interested in used ones.


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Thanks all for the advice, I compared to good bolt, and there is only about 1/2" threads remaining.

The bolt got harder and harder to turn, so I put a lot of leverage on rusty bolt and that did it. I may try tightening bolt, as I backed it out, it was always easy to turn clockwise.

I messed up threads with vice grips, I’ll see if I have a die that size.

Paul’s idea is good, getting PB blaster from the top. I’m going to order two new bolts, so I have plenty of time to get it out. In

Success! A lot of PB blaster, a few whacks with a hammer, my trusty pipe wrench, and LOT of muscle, and I got it out.

I then repeatedly sprayed PB blaster, chased threads, sprayed carb cleaner, chased threads until I could almost hand screw the bolt in/out. Then put a bunch of copper anti-seize and chased one more time. So threads are good.


OK, I’m confused. We don’t care about the threads on the bolt, as the head is broken off anyway. How could you mess up the threads in the hole with vice grips?

Confused again. You’re not going to install some Grade 8 bolts purchased locally? You think there’s something special and wonderful about the POS you just broke the head off of?

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Eh? I messed up the threads on bolt - Someone suggested putting two nuts on bolt. The body threads are good, just had a lot of rust deposits to clean out.

I assume the OEM bolts are grade8 or better? I guess I could buy grade 8 bolts myself and drill a hole in them for the wire. Are the yellow zinc plated fine? Or do I need stainless steel?

I seriously doubt if the original bolts were any better than Grade 5. They weren’t stainless either, but stainless might help make them easier to get out next time. Definitely calls for anti-seize.

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I knew you could do it. One of mine broke off flush leaving nothing to grab hold of- and the drilling and removal was a real PITA!

Thanks Dave! Yeah, I’m lucky I had enough left to work with. PB blaster and brute strength have helped me out of a lot of situations.

Got two grade8 zinc plated bolts for $3.00! Luckily it’s common, 2" - 7/16" fine thread. I’ll drill holes in them for the safety wire.

Tomorrow I can press out/in the small bushings with a socket. For the large bushing, I’ve got the sacrificial URO bushing ready to press in the big one (I cut out interior). But because of that ridge, I can’t press out the original. Sounds like a hacksaw is in my future.

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Hey: batting .500 will getcha into Cooperstown.


Grade eight bolts? Good luck with the drilling!

Nothing a good sharp HSS drill bit can handle.

Gee Dave, I thought your post was Kirby :wink:


When I worked for a living maintaining fork-lifts and other heavy stuff, all of the nuts and bolts etc came from a central storeroom inside the mill. All that was available for many years was Grade#2.
Then a new supplier showed up and we got an assortment of Grade#8 hardware.
Stronger, tougher, harder, right?
I started using them, and soon discovered that if one of those bolts broke (and the trucks all had a hard life) I would have an awful time digging the thing out. I started to be more careful after that!
Mind you, all of our drill bits came from the same storeroom!
When I dropped the cage in my car I used Grade#5 bolts, and never-seize!
Your choice!

Managed to drill thru bolts with two hardware bought bits, but each was shot by the time hole was done.