6.9 Damping.

[WGB]

As mentioned in another thread I appear to have a lack of damping in the left rear strut which makes the car handle better to the right than to the left.

What actually does the damping in this suspension.

THere is one documented loose ball joint in the right side but the lack of damping seems to be in the left.

There seems to be plenty of air in the spheres as witnessed when running over large road traffic flow bars but the left rear is noticeably underdamped.

Advice gratefully received.

Bill

[WGB]

As I have said in another post  - I discussed my 6.9 with one of the mechanics at Diesel Motors yesterday who was one of the Service Managers for years before becoming disenchanted with dealing with the public and returning to the spanners.

He has some corporate history and knowledge of the 6.9 suspension.

His suggestion was that the underdamped unit is the flat sphere and so I will replace the two rear spheres at this stage and see what happens as well as deal with the rattling ball joint at a future date.

I will probably replace all five in the near future but I have spent enough money on cars this week.

Bill

[koan]

Anyone care to comment on whether I might be correct?

What about swapping the spheres side to side, then seeing if the problem has moved?

koan

[WGB]

Sounds eminently sensible Koan but I think when I swap them I'll just put in new ones.

I know there are others here who sem to be able to swap spheres quickly but I'nm sure it will take me quite a while on the first attempt.

Bill

[koan]

Sounds eminently sensible Koan but I think when I swap them I'll just put in new ones.

That's assuming new rear spheres will fix the handling.

The underdammped condition you describe is more likely to be a front sphere{s) problem.

In my limited experience as the spheres age,  the rear end just gets stiffer and  stiffer, transferring every little road irregularity to the body, whereas the fronts produce a wallowing sensation as they reach the end of their life.

I don't have much faith in M-B mechanics and hydro suspension. The one person I know of who owned a 6.9 from new in early 80s ended up selling the car after paying many dollars to the dealer to get his suspension fixed, they never sorted it out.

koan

[WGB]

I will be replacing all five but if I just start with the back two we will see what eventuates.

Bill

[koan]

Maybe worth checking to see you have the correct spheres front and rear,  from memory the front three should have red dots, the rear two blue dots.

Dot is not the right word, splodge of paint would be better, it's daubed on the necked down bit where the hose connects.

koan

[WGB]

That is a very good point Koan - I will be checking to see things like coloured dots and just how old or new everything looks.

I have really only driven the car home (Best part of an hours drive) and the twisty road around my house was a bit scary with the left rear side appearing unstable.

It has been raining all week and I have decided never to drive this car in the rain and I need to move my other car which is stripped for painting out of the way to get this car on the hoist - again I cannot park that car  outside because of the rain.

Apparently we are expecting a fine weekend so I will be testing and poking around as I have three days off.

Bill

[peterq]

You've probably already made some progress with this, but for what its worth...

When I first had a sphere fail it had 2 effects:

- when parked the corner with the bad sphere was nearly solid, you couldn't bounce that corner of the car.
- on some corners or undulating surfaces the car set up a weird corkscrew motion. The bridge south of Bridgetown was especially good for that.

No point in swapping spheres side to side, for the effort involved and the relatively small expense of the spheres its not worth it. I got my spheres and struts from Lintrex in Welshpool. OEM at reasonable prices.

[koan]

...relatively small expense of the spheres its not worth it. I got my spheres and struts from Lintrex in Welshpool. OEM at reasonable prices.

Dare I ask what you paid for spheres and when?

I replaced all mine about 5 years ago (before record keeping) but it won't be long before they need to be re-replaced.

koan

[WGB]

I went into Diesel Motors in Perth and was told $738 each for the rears - I think the fronts are dearer.

I have ordered two from Styria and they are in the post at $298 each plus postage.

I had another offer to get them from Singapore for a bit less but I am contining with the two rears from Styria and after they are on and I have examined the rest of the system I will decide about the rest.

There is a rattle coming from the left rear which I thought was a worn ram ball joint but Styria has suggested it may be the sway bar mounting. I haven't had it up on the hoist but will go over the whole suspension when I do the rear spheres.

At the moment the front damping and springing seems fine and the car doesn't sink at all so I am not going to do the standard - "all 5 spheres" - immediately.

Bill

[s class]

$738 each for spheres?  That's robbery. 

I've just bought a second set of 5 for the AMG.  Bluey gets a set too. 

[peterq]

In January 2005 they were $240 each from Lintrex. An invoice in April 2005 from Auto Exclusive in East Perth has them at $250 each.

[Big_Richard]

In January 2005 they were $240 each from Lintrex. An invoice in April 2005 from Auto Exclusive in East Perth has them at $250 each.

I got mine for $250 each for all 5 too.

[CraigS]

It is often quoted that the spheres should be changed every few years, and that the price to do so is reasonable ! Personally, I don't consider $1500 (plus labour if needed) is a reasonable expense every few years. I know they last longer than that, but obviously they do deteriorate over time as the gas  dissipates.