Major Problem, Help Please

[DavoVP]

Hey all,

I decided it was time to renew all my bushes under the rear but long story short i was handed the torque wrench didnt check it and striped the thread out of the upper control arm to body nut.

The only nut thats welded to the body and is in a prick of a spot.

How can i fix this........... I would realy like to fix it lol.

Thanks guys

[Brett_jjj]

Jeez ,what a prick of a thing to happen.The only thing I can think of is to try either retapping the thread,cutting the welded nut off and use a new nut,or get hold of a longer bolt and put
another nut on the end of it where it protrudes through the stripped nut.

[DavoVP]

I cant see a way to cut or place a longer bolt with a nut on it. There is a small cut out in the chassis where the nut protudes into the body of the car its self.... If i taped id haft to go a larger Bolt and i cant do that as it passes through a bush.....

[Brett_jjj]

Yeah,I get what your saying.I know they are in a prick of a spot.I did my rear bushes a years or so ago.You might have to remove the whole control arm mount from the body and reweld a new one there.Id say they are just welded on.I cant remember,Id have to go and actually have a look and its pissin down rain outside..You would just have to mark exactly where it fits up to the body, and grind away the weld.Fit up the new one.A smash repair place might do it cheap.Are they actually a seperate mount,or are they through part of the body.I cant remember exactly how they go?

[Brett_jjj]

Just trying to look at a pic of them in a workshop manual but its a bad pic and you cant seee them properly. .I will have a look in the morning and see how the mounts are actually connected to the body.I will post back then what I think.

[DavoVP]

Was just doing a bit of reading, A helicoil may be the way to go. They seem to be sweat welded onto the rear floor pan. I dont realy like the idea of removeing that...............

And thanks man, any help is welcome.

[wortus]

Was just doing a bit of reading, A helicoil may be the way to go. They seem to be sweat welded onto the rear floor pan. I dont realy like the idea of removeing that...............

And thanks man, any help is welcome.

If you can get a drill and tap in there to prepare the hole for the helecoil I would try one of those first. Make sure you tighten up the bushes with the car resting on it's wheels.

[Brett_jjj]

These bolts tighten up to around 75 Nm.I doubt a helicoil will hold under this pressure,but its definitely worth a try.Its still raining here so I havent had a proper look at the mounting yet.

[wortus]

These bolts tighten up to around 75 Nm.I doubt a helicoil will hold under this pressure,but its definitely worth a try.Its still raining here so I havent had a proper look at the mounting yet.

I had a quick Google on this and read that some Mercedes aluminuim blocks have helicoil inserts for the cylinder head bolts. As long as the helicoil is correctly fitted it should take the same torque as the original as they are stainless steel and you can even get them in titanium. Where I work they use them a lot when threading into metals like lead and they attach lifting points to them.
The hardest part about fitting them properly is redrilling the hole and getting the drill in straight.

[Brett_jjj]

Just had a look at that mount,and I doubt you could get to it properly to fit a helicoil,or even to grind off the stripped nut so a new nut could be used.Theres just not enough room in there..I think a panelbeaters would be the best shot.They would have to see these mounts bent on some of their cars they get coming in.So they might just fit another mount,or maybe theres some other trick they know of.You must have put some tension on it to strip it.It not a very small bolt or nut.What was the torqure wrench set at? Anyway,after having a good look at it,I cant think of any other way of fixing it.Sorry mate.Hopefully,someone else here might have an idea though.

[DavoVP]

The wrench was handed to me at 120nm the nut and bolt only needs 54.

Two lessons learned here, A LED torch doesnt make a very good work light, and sencondly always double check a Tourque wrench when its handed to you.

I managed to get it with a grinder, I was able to get it in there enuff to cut 3/4 of the way through the nut without touching the floor pan/chasis rail. After that i simply twisted the old nut off with a spanner.

Held a new nut in there with a spanner and some tape Tightened her up and she's all good now.

Thanks heaps for you suggestions guys, This site always seems to help where it can.

[Brett_jjj]

Yeah,good stuff.I had a look and it today,and it looked like it would have be a struggle to even get a grinder up in there without damaging anything else.Its about the only way it could have been fixed though without having to replace the whole mount .Cheers .