award78

Hell all, I recently busted my rear sub-frame where it bolts to the rear lower arm bar (brace). The bolt is stuck in the sub-frame just spinning loosely directly after it snapped, so I can only assume the threaded part (or anchor point?) is broken off. Do you think its possible to just cut the bolt off and use a new nut and bolt without welding the nut to the sub-frame (which might avoid dropping the whole thing)? Or just weld the bar to the sub-frame, for a permanent solution...till the diff goes. The only other option is very labor intensive and expensive....if i can find a sub-frame.

Thanks

Car Analogy

Lower arm bar? You mean lower control arm?

Are you saying you are trying to remove the lower control arm, but the bushing bolt that mounts it to the subframe is not coming out? It spins and spins but doesn't loosen? You suspect this bolt has snapped? But then why doesn't it just slide out? Unless its frozen to the inner bushing, which has split from its outer, the rubber has split, which allows bolt to spin, but bolt can't come out?

This happens all the time with front Compliance bushing front lower control arm mount. Never heard of it happening to rear on our cars. But remedy would be same. Cut bolt out with sawzall. Replace bolt and nut and bushing. Lube new bolt with antiseize.

award78

Sorry, I'm explaining it wrong. I mean the lower sub-frame brace that connects the two sides of the subframe underneath the differential. it's just a bar with no bushings.

s2000Junky

I'm guessing its the small stamped steel cross brace being explained here? A pic would be good. If so, its not a high load bearing piece just 2 small 10mm bolts on each side that hold it on if memory serves. Its important, as you don't want to run without it, but one stripped bolt isn't going to be catastrophic, certainly if you can just re tap it or run a bolt through and nut on the other end as explained.

award78

Yes, I don't have pics personally yet but it's the crossbar explained in this writeup: https://www.s2ki.com/forums/s2000-mo...ie-bar-849991/
I'll have to take the EVAP canister off to get a new nut on. I'll try that first. Thanks

Bama Dave

Get a tire shop or mechanic to retap the threads if possible. Those bolts over time become harder to get out for some strange reason. Good luck man

DefSport

If it "snapped" but is still captive in the subframe, it sounds like the welded nut in the subframe popped the small resistance welds they use to secure the nuts. Sounds like things are pretty rusted to pop those welds, so the usual method of holding it down with some pliers to put load on the nut and then spinning the bolt with a socket won't really work (this tends to trash the bolt, but not hard to replace once out obviously).

I'd probably cut the head off the bolt and try to get it out through the subframe tubular member, and then do a nutsert or something like that in its replacement.

award78

It seems like this is exactly what happened, the bolt is just spinning freely but won't come out so the nut broke loose but still on the bolt. Once I get the bolt/nut off, I was thinking of just using a serrated flange nut like this:

https://www.boltdepot.com/Product-De...?product=17718

You think it will hold?

DefSport

I'd use a nylon locking nut over that personally. I looked at my subframe yesterday, and yea, you'll easily have access once you remove the nut off the bolt. You should have access to it, so grab it with some vise grips and get it undone, then get a new nut and bolt and you're good.

Car Analogy

A loose nut floating up there is going to be a bitch to get the bolt to tighten. Nothing to hold the the nut in place as you tey to ha d tighten the bolt into place. Even if you can get a tool back in there, it will always be a pain to remove or install.

I would JB weld a nut into place. Being very careful not to get any on the threads. You just need enough of the stuff to keep the nut from turning as you hand tighten, or loosen, the bolt. Be sure to use plenty of antiseize on the bolt so no future corrosion causes problems.

I hate to have to say this, but I must least someone ignorant misunderstands. The jb weld isn't being used to secure the brace to the subframe in this application. It only holds the nut in place so it doesn't spin as you start to thread the bolt. The bolt and nut are what are supplying the clamping force.