issue with trailing arm mounts (V4 STi gf8)

[STiNGR]

Was putting in my V7 rear sub frame in today and then I got to the factory V4 trailing arm mounts I started to undo the 3 bolts. Got 1 out moved onto the next and the bolt started to get very tight, I kept on undoing in and then it made a big crack now the bolt I'd 1/2 unscrewed from the chassis but only spins its like the thread sleeve is spinning and do letting the bolt come out.... Is this a possible issue? If so what is a solution to fix this problem and get the bolts out. All the rest are having the same problem but I'm not letting them get to the spinning point.

[Koom]

Sounds like its broken a weld nut. If it's a nut that's inside a chassis rail, you may have to cut the head off the bolt to get the subframe out. Sometimes if you're lucky, it's possible to get a spanner or vice grips onto the nut to get the bolt out.

Then the not so fun part, is trying to figure out how to weld another nut in its place without having to de-stitch the metalwork.

[Rosssub]

Stripped thread or the nut thing welded inside the chassis rail has rusted and broken free? The exposed bolt thread inside the chassis rail would have been rusty too, so wouldn't want to wind out.

Sounds like you will have to grind/cut the bolt head off, remove the sub frame, then sort the bad thread inside the chassis rail and fit new bolts.

[STiNGR]

I've got new bolts etc, subframe is out. Its just the trailing arm mounts that's still connected to chassis. If the weld on the nut is broken on the inside of the chassis rail how the hell am I going to be able to get it out and repair? I would have to cut chassis rail and that's out of the picture! Seems like I'm fuked. All signs are pointing to my theory that car was flooded/salt water damaged! Found that one of the rear hubs is completely blowen to pieces so I'm hoping I can use the V7 ones on the subframe that's going in....

[gotasuby]

leave the mount on and just take off where bush is?

[STiNGR]

 gotasuby said:

leave the mount on and just take off where bush is?

I'm going to do that with the other side. Still have the issue trying to fix bolt in question.

[Rosssub]

Maybe fit a threaded stud into the hole and weld it straight to the chassis?

[STiNGR]

Got told a fantastic idea (in my eyes). I think I'm going to cut a wee hole in the body by the rear seats right above chassis rail where my rouge bolt is, fish out nut and weld in a new one, then patch entry point in body with panel steel super tidy. Bobs ya uncle....I hope.

[Rosssub]

After you cut through the body panel, you would still have to cut though the top of the chassis rail to get in. Which would be super tricky to patch up (wof/cert),welding through a hole in the floor.

[STiNGR]

 Rosssub said:

After you cut through the body panel, you would still have to cut though the top of the chassis rail to get in. Which would be super tricky to patch up (wof/cert),welding through a hole in the floor.

I'm kinda shagged then aren't I? Re-shell....

[Guest]

They would never find it if its under the carpet only if it went for revin. Go for gold buddy.

[STiNGR]

 evowrx said:

They would never find it if its under the carpet only if it went for revin. Go for gold buddy.

Rego is on hold so I'm pretty sweet there. Its my only option really so I may as well go balls deep and do it a!

[hijacka]

Apply heat carefully with a oxy or gas torch on the bolts and undo the other 2 bolts on that side, then apply leverage and heat to the stuck bolt and try to undo(grunty rattle gun helps) ..of course make sure you lift carpet/seat etc up and anything else at risk of burning.. die grind out the hole and weld a nut in there.

if the bolt thats spinning freely wont move grind off the head and die grind out the hole.

If you can't get the 2 bolts out at the start then umm just use more imagination..

Mainly see the gbox Xmember bolts doing this

Got those other arms here ready will get them to you soon