smo0othride

I replaced the torsion bar bearing on my ML500 and when putting the bolt back in it got stuck. On one side I can't tighten it or loosen it, the head of the bolt is slightly stripped but not extremely bad. The bolt on the other side will loosen, but I can't get it any tighter. The truck is sitting extremely low in front, and I think if the torsion bolt is tightened all the way it should be sitting at it's highest setting instead of the lowest setting. Can anyone give me some guidance?

PelicanParts.com

Remove them both, heat will help.

The threads must be cleaned/repaired on the bolts and nuts.

It is possible the parts may need to be cut off and replaced with NEW.

whunter@pelicanparts.com


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smo0othride

I think I can get them both out if I really put some effort into it. What is the best way to clean them? Wire brush? My main concern is why I can't get them to go in all the way. I read these are special bolts which are meant to curve as they screw in. Mine keep getting stuck before they are in all the way. Am I right that if they are all the way in that the truck should be sitting at its highest setting instead of lowest? This is extremely difficult today because it really requires 3 hands, one to hold the plate in place, one to hold the nut, and one to tighten the bolt.

PelicanParts.com

The bolts are bad if they are warping/bending under load.

whunter@pelicanparts.com


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athenshome

Do either of you have any suggestions or tips or getting the torsion bolt back into the thread? I've just removed my torsion bracket to replace the bushing, and I cannot get this bolt back in the thread for the life of me! It seems that the nut starts out at a angle, but I cannot seem to get them connected. My bolt thread seem to still be in decent condition.

Any suggestions or tips on how to reinstall this bolt would be greatly appreciated! Thanks

mihir_d

What started out as a simple DIY. The bolt will not come off on the driver side. It is now neither screwing back in nor coming out. Stuck at 45mm ride height setting (lowest). The threads do not appear damaged in any way.

Gotta rush to my Indy mechanic tomorrow to raise it on a lift & see what’s going on.

Did anyone find a way of resolving this?

chassis

Does this help?

mihir_d

I had nudged the bolts a bit & sprayed wd40 on both a day prior as per this video.

I think, the bolt MUST be installed with antisieze on it since these only open once every 7-10 years.

Mine were last replaced in 2011 by an indy mechanic. I bet, he didn’t care to put antisieze.

The threads & Bolt most certainly need some thread repair. Best to be handled at a shop.

Its best done by lifting up the vehicle on a lift.

My upper body got all torsioned out this morning fussing with these bolts with the vehicle on jack stands , but they will not unscrew, no matter what.

This is is a simple diy only if the bolts will easily come off. I will make sure, my Indy puts the antisieze when he gets this sorted out.

chassis

If I were doing this job, I would use an impact wrench to get the old bolts out, and use new factory OEM bolts with a torque wrench for reassembly.

mihir_d

Tried breaker bar first, then impact wrench. No luck. I didn’t want to try too hard for fear of damaging the bolt head/threads.

Maybe, it is easier to loosen the bolts with car still not raised on jack stands, due to how the assembly is at an angle due to the torsion bar spring.

I’ll know soon when it gets to the indy shop. Will keep you posted.

mihir_d

I was finally get it to my Indy's shop this morning.

This bolt is a real pain. As expected, I am not the 1st person to hit this problem of bolt spinning in place..neither coming out, not going in.

It seems, there is a nut on the other side, and my Indy could confirm by using a flash light that the nut is spinning with the bolt.

The nut is probably welded to the frame? And over the years, the weld has taken rust and has broken off the frame, cause bolt and nut, both to spin together?

I found another thread that has some pictures for a better understanding.

https://www.benzworld.org/forums/w16...olt-stuck.html

This seems to be a fairly common issue...

mihir_d

A specialist mechanic specializing in Suspension work finally fixed it today. What a relief! $280 in labor (no parts needed, bolts were fine, nuts were stripped, he replaced them at no cost).

He suggested, easiest way was to release the torsion bars from the very front. The front bolting of the torsion bars to the chassis is much easier to access. He released the pressure on the torsion bars, and then said, undoing the tensioner bolts was a piece of cake.The bolts were fine, so was there no damage to the torsion cage, but the nuts had the threads stripped..and they were spinning.

He cleaned up the support brackets, greased the bolt well, put new bushings, plates and held the nuts with a very small tig weld in place as the bolts were getting screwed in. The tig weld will snap as soon as the nut is forced to twist its angle.

This tensioner bolt/nut is certainly not a rookie DIY job, especially on these older cars. They might be easy to remove the initial few years, but with 15+ year old cars, you need someone who knows/has the tools on how to work around these bolt stuck/seize issues.

chassis

Glad you got it sorted.