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1999 ML320
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Discussion Starter #1 (Edited)
Got on with cat repair and started to undo torsion bar bolt. Result bolt spinning no way of getting to the rubbish captive nut within the vehicle frame. Two days of pain, no car. If you think well i'll just drill the head of the bolt, think again.
This bolt is made from very high grade steel and took me 3 hours to remove, in the end with 10 masonry bits as nothing else would touch it and a big industrial hammer drill. So be warned if the frame around the nut ontop of the torsion bar deforms and allows the nut to turn you are in the shit.
Unless you can get that bolt head off, you are going to need a tow truck and some way of getting it on that truck as there will be zero supension on one side.
Not had a good two days in the rain on my back. Spent the first day trying enything i could to get the nut from spinning but there is no way. There is only one inch room ontop of the chassis and the captive frame around the bolt will not allow you to get a spanner on it fully.
Anyway took a few pictures. Hope it helps the next poor B______ who has this problem.
Mine did not have the rubber bellows on the bolt. Someone had not bothered to re-install it and was just inside the chassis block. You will not be able to tell if yours has the bellows attached as you can't see them till its undone, HOWEVER the bolt was in very good condition?. Front of torsion bar just undo the two bolts on the lower wishbone bracket and slide the sleeve back. It may or may not need a little help. Watch your fingers as once you slide it back it is a but joint and the bar will want to trap your pinkies against the floor of the vehicle.
Oh and the nut and bolt head are not normal. They have a swivel curved bottom to allow for the change of curve on the bolt as it is tightened. Bolt and nut it not sold seperate so you need to buy the whole end unit £250.00 at MB.
 

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Discussion Starter #3 (Edited)
After some thought i think the only way to prevent the frame that holds the nut from spinning is to slide an angled 19mm ring spanner into the 25-30mm gap at the top of the chassis box and then undo the bolt. This will ensure that the bolt does not start to turn in the frame. You will only get partial access to the bolt head.
This can only be done at the very last half inch of the bolt as it will be to far down inside the chassis to reach if you have a problem further down the bolt. It will be the end of the bolt that gets the weather and will be far more likely to get rust.
Mine got very hard to turn at the last 10-15mm, although i had no idea how much i had to go untill i hit this problem. You can just about feel your way in above through the hole. See picture. Hope this helps someone, i had to learn to see with my fingers with this one. Like with everything on this vehicle you will not fully understand till you do it, but you will be way ahead of me with these pictures and some insight of what to expect.
If you can't afford the time if it all goes wrong take it to a shop and find a backup part as the shop will want it off the lift if they hit the same problem. My part is on the way from ebay and have had to use a temp bolt while i wait. I will be glad when this is sorted and i have STILL not got my cat done.
 

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Discussion Starter #5 (Edited)
No stuffed inside the chassis. Some lazzzzzzy Bast at the dealer had a hard day.
I must just add that i think this is a one in a thousand vehicle thing. The dealer said he was surprised at the problem and new very little about the part. So its toss a coin about a thousand to one odds. There are only a few threads on here about the same problem.
But would i open up the other side. Not unless it was needed thats for sure.
 

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ML320 2002
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WIS says bellow should be covering the bolt and also filled with grease. Devil is in the details. You became the victim of whoever removed it in the past. He might have stripped it too. Otherwise, it bolt would come off without much difficulty.
 

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Discussion Starter #7
After 3 hours of drilling with a heavy duty drill on and off for tree hours the bolt unscrewed very easy at the end. But i do not know what condition it was in at the start. It was darker at the end so suspect rust. It was exploding rust when i got 2ft ext bar on it. But that is the key to this whole thing. Untill you try to undo that bolt you are not sure if it has the bellows or not.
And if it all goes wrong you have got no car till its fixed because it is a tow truck job.
 

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If you want to to check if the rubber boot is in place, it is possible to pass your hand behing the torsion bar housing and feel the tip of the bolt with finger.
 

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Discussion Starter #10
As you can see in picture 1 and 2 the cage around the bolt which is to stop it turning has deformed. It is made of mild steel and is rivited to the torsion bar. One rivet had stretched and as you can see where the black paint has come away is the point of deformation. It should have been high grade steel which would not have caused failure and is another bad design issue with the ML. The design of the bellows allows no visual confirmation that they have stayed in place once tightening of the bolt takes place, which may be the reason why mine was found inside the chassis.
 

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Discussion Starter #11
Quck update changed torsion bar and bolt. The only chance you have got if your bolt spins is to pull back the front torsion bar sleeve. If there is tension still in the bar this will be very hard. Thats the only way i can think of to get the torsion bar out if the captive nut spins. But this can only be done if all tension has been released. Be very carefull as this thing could harm you.
As for the bellows what a piece of crap. No way can that thing full of grease stay on while you install. No wonder i found it loose inside the chassis. Going to see if i can slip it over the top tomorrow but if i cant bollocks to it.
 

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As for the bellows what a piece of crap. No way can that thing full of grease stay on while you install. No wonder i found it loose inside the chassis. Going to see if i can slip it over the top tomorrow but if i cant bollocks to it.
megadamp, the first picture is from my car and shows the window I was talking about. If you want to place the bellow, you need to remove the silver plate on yours because it is covering it. I think the previous guy thought bellow is only for the dust and decided to cover it.
 

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Discussion Starter #13
Merzatt you would need 15 inch long fingers and hands like a girl to access either way. Have you tried it.
 

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Merzatt you would need 15 inch long fingers and hands like a girl to access either way. Have you tried it.
It is not impossible but requires patience to figure it out. It took me 30 minutes for the first boot.

Tip: Do not tighten the nut fully before you pass the bellow on. If tip of the bolt positioned 1" lower than the top of the frame, it will give you chance to bend the boot downward and find the tip. Once it finds the bolt, sliding it over is easy.
 

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Discussion Starter #17
Quick qustion. Would it be possible to relieve presure on the torsion bar if mostly undone but not fully due to rust/cage captive failure, if using a jack under the brake disk, the roll bar, shock and upper wish bone was disconnected. Then lower jack to relieve pressure on torsion bar. Would this work?. Would drive shaft extend to far and get damaged.
 

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Mark every piece for easier re-installation. Most of the tension has already been released with the front wheels being off the ground. But removing the shock and the sway bar would help.

But I fail to see your concern about the drive shaft. Or am I missing something?

Below are part numbers that you might possibly need if damaged.
 

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Discussion Starter #19
Thanks 43. Its just how far down the lower wishbone can move with the driveshaft attached. Wragie's trying to find a way to remove torsion bar without killing the one he has got. He's got the nut spin thing.
 

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For installing the rubber bellows, would it be a good/safe idea to put the bolt partially (just poking out the end of the nut), then lower the front end slightly to load the bar? Would loading it give you any extra room between floor of car and head of bolt to slide on the bellows?
 
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