[jdzacheis]

I went to go remove two subframe bolts to install Cusco under chassis bar. One came out fine, the other (passenger side) bolt was turning but it was difficult. After tightening, loosening, tightening, loosening trick the bolt just started spinning in place. It didn't break, it's still in the car but I can't tighten it or loosen it, it just spins.

So I think that whatever the bolt screws into (not sure if it threads directly into the chassis or to a nut welded to the chassis) has become loose and is spinning.

Anyone know of any access point to the top of this bolt so I can repair it. Google hasn't helped me much.

I was really worried at first but I'm not too worried about now. I think I'm kinda lucky, I'd rather have this than a broken bolt to drill and tap on the frame and that bolt was maybe 2-3 mm backed out so the subframe is still supported.

 

[moo11123]

did you round the bolt? can the socket grip on the bolt anymore?

 

[jdzacheis]

No I didn't round it, the bolt is spinning, not the wrench/ratchet

 

[PETER PAN 2009]

That is a big bolt with the pointed nose. It joins the sub frame to the chassis in tension by wigglling the sharp nose into a smaller hole on the chassis, in effect stretching the sub frame and bending the chassis for a very hard fit.

Looks like by wiggling the bolt back and forth, the chassis has cut a new flat thread on the bolt. The bolt is turning around on this flat and round thread and not moving in or out.

You need to pull the bolt out a little while turning it, so the edge of the chassis will follow the old thread.

I would insert something like a flat head screw driver, between subframe and the bolt's head, and pry the bolt out while turning it. Hopefully the chassis' edge will follow the old thread.

 

[jdzacheis]

So you are saying the threads that the bolt screws into are directly tapped into the frame yes? And that the nose of the bolt fits in a very tight spot within the chassis and that the chassis has in effect created a groove in the bolt which it is spinning freely on?

I'll give it a shot but just curious, the bolt is only backed out about 2-3mm which means it's still threaded into something. How is it able to freely spin? The bolt is acting like there is a nut on the other side that isn't connected to anything, just spins.

I'll give it a shot.

 

[wayne0]

Threads could be stripped. I've had it happen in other situations. Other than drill and tap, I don't know the cure.

 

[jdzacheis]

Threads could be stripped. I've had it happen in other situations. Other than drill and tap, I don't know the cure.

Pretty sure the threads aren't stripped because in order for the entire bolt to just spin in place (bolt can't be tightened or loosened, just spins) all of them would have to be stripped which would take an incredible amount of force. If they were stripped to that degree the bolt would just fall out.

I'll keep it in mind though, I've had much experience with extracting/fixing broken bolts.

 

[dentman]

If the bolt won't come down any further by putting tension on it with a pry bar behind the bolt head flange, the nut that is welded inside the frame rail has likely broken free. It happened to my rusty 00 GTS race car (on both sides) when I dropped the subframe to install a new anti-roll bar. I had a similar issue with a 1995 Celica we were parting out.

There may be other ways but I cut off the head off the bolt with the grinder and dropped the subframe out of the way. Then I cut a small rectangular "window" access on the inside of the frame rail with a small grinder wheel and removed the other half of the bolt. I placed a new grade 8 nut inside the frame and tack welded it into place.

An unexpected delay in the build process for sure.
Hope this helps.

 

[PETER PAN 2009]

If the nut has gotten free from the chassis, you can try clamping it with a vice grip to lock it in place, while turning and prying the bolt out.