Viano torsion bar failure of mounting

[josepherely]

Have an unusual problem (I hope for Mercedes sake it is unusual) with the rear torsion bar on a Viano Ambiante (with air suspension), medium wheel base 3.2L. The anchor for the torsion bar has been torn out of the body/chassis on one side leaving that side of the bar dangling and hitting on the rear drive shaft. Obviously whilst doing so it doesn't serve its design purposes, let alone the drive shaft interference. When I say torn out it would have required considerable force to leave as much damage behind on the chassis. I can't see any mechanism for why the mounting (not the bushes) should be able to be pulled out. I have had a lot of problems with the build quality of the chassis and lose fittings, it could be that this was fitted loss originally allowing it some movement tolerance? The car/van is just 2 years old, 50,000 KM and has not been abused or heavily loaded. I have a photo if anyone is interested or could help give clues? Apparently they will have to replace the chassis components. I hope for Mercedes it is just a fault on my car and not a design/build problem as it could be an expensive recall issue for them. The rear suspension had been creaking for quite a while, and only in the last month or two really banging, so likely that came lose and then completely torn out.

Also interesting to know if you feel this is warranty issue or user damage?

 

[turnipsock]

You mention that there was 'creaking'. Do you know the exact source of this?

It may be that some other part of the rear suspension was sticking/jamming and the result was the rear antiroll bar was being subjected to an unusual load...hence the problem.

It may also be that something was loose and all the cornering forces were being taken by this mount.

The rubber bush doesn't look like it has had much abuse so I don't think you could class this as 'User Damage' by any stretch of the imagination.

 

[Bolide]

It's the rear antiroll bar. There should be no load on the mounting if the bar is working correctly and you're going over symmetrical bumps. There will be some load over assymetrical bumps such as some speed humps

If it's been groaning & banging for a few months then you could have prevented the problem by getting it fixed at once. Right now all that needs to be done is to weld a small plate across the hole, redrill the ARB mounts, treat the new metal and refit the bar. A couple of hours work for an independent

You need to find out why it was groaning. Probably the ARB bushes need replacing and, if there are bearings in the ARB drop links, they need to be checked

I would think the cause of the damage is probably speed humps. If the ARB mount was loose it would tend to stress the mounting point and would gradually work & tear the floorplan as the photos suggest

Nick Froome
www.w124.co.uk

 

[josepherely]

Thanks Nick,
The creaking wasn't specific or didn't seem to come from anywhere in particular or seem worrying, also it would seem to settle down after a while or only be appraent when driving on an uneven road (which would suggest suspension probs I know). I would not be surprised if something had been lose or not adjusted as many things were lose or not connected properly on several "less essential" parts.

Speed bumps would in my world be normal parts of the driving environment so surely the design would be strong or robust enough to live with the resulting stress on the part?

 

[Bolide]

It probably only failed once the mount came loose and started tearing the metal. It's lasted 2 years and I wouldn't think it would have done so if it was loose from the factory

 

[enscjb]

looks nasty

There looks to be some surface rust around the jagged edges of the hole, I guess this happened after the failure.

Seems an add failure, I agree.

I was interested to hear your other experiences with the vehicle as I'm about to buy one.

Regards
Chris

 

[josepherely]

The Engine and drive are excellent, I have the 3.2 v6 which gives it enough power. The space inside is excellent.

The build quality however lets it down, with some poor designed fittings that are not up to the job of a family car. Had issues with many bits not correctly mounted or tightened, rust on the body and fact that the radio can't pick up LW correctly. May have just been that it was a Friday afternoon lemon, however the after sales service was not too bright either in clearing up these problems (took them 2 years to give me all the bits that were supposed to come with it new, told me to wait until next service about the problems with the suspension).

Overall happy with the car as does what is needed on carrying the family around, but for the price, and for a Mercedes expected a higher quality (or at least the same quality) as a Japanese car. Would I but another car than this? After the experience if another manufacturer (Renault, VW etc.) had a vehicle of the same size able to carry 7 people AND luggage then I would probably go for it, however there is no comparable vehicle on the market except for a transit minibus.....

Hope that helps

Joe

 

[mark999]

Try the new VW Caravelle with Long wheelbase and the 174ps diesel engine.
After my experience with a V-Class I will never touch a Merc van again.

 

[josepherely]

Thanks Mark, I will have a look at it
Joe