6.9 struts - info needed

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Styria

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I have previously referred to the fact that at least two or three 6.9s suffer from a lower suspension setting on the right hand front. No one came up with any suggestions, let alone remedies - if there is one. It just so happens that I have in my possession two front struts that were fitted brand new just on ten years ago. I cannot remember where they came from - in fact, a repair shop now no longer in business procured the units but, as I said, from an unknown source.

Examination of both units revealed that both top mounts had slightly squashed rubber components, but more importantly, the right hand unit displayed evidence of external leakage. Now, both struts came from a car with the 'lower' height issue on the right hand (driver's side) side. Further testing seemed to indicate that there was not a lot of 'drag' when pushing and pulling the unit, and this would indicate that the various seals have lost their stickyness. Now, it's been said that these struts are virtually a 'lifetime' job without any maintenance being required, as long as the dust seals are in good condition, and that there should be no external leakage, whilst some internal leakage was acceptable - as long as it'd pass the leak test carried out by disconnecting the thin plastic bleeder line. Surely, the strut cannot last forever, and surely also there must be some deterioration in action and performance which may well lead to slight dropping of the suspension. Anyone any thoughts on my theory, or better still, provide us with a definite answer. Regards Styria

Apologies for post by moderator.
 
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260ebenz

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Styria sent you a message in regards to your question hope it is of use to you?

Cheers.
 

WGB

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Hi Styria,

1) Does this right side lean only afflict RHD cars or do LHD cars lean one way or the other?

2) My 6.9 definitely leans to the right while settling but is level when pumped up. When fully settled there is definitely a small lean suggesting the RH bump stop is more compressed. This would go with the fact that my RH strut seems softer than my left when driving.

I was going to purchase two new struts this year but they have now become unavailable so was then going to try two "Styria Recon Struts" when a pair of strut kits appeared on ebay.

My struts have no external leaks and it will be interesting to study what comes out. I have not performed a leak test but I am sure my RH strut is leaking past it's seals internally.

Here is the content of one kit and I have photographed and measured the individual parts

StrutSeal2-1.jpg

I hope these are the correct parts or else I will be appearing "cap-in-hand" to Il Duce.

It has allowed me to re-direct my budget and spend some money on one of my last big ticket items - a new rear window to replace the de-laminating original and the three other second hand imperfect ones I have collected.

Bill
 
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Styria

Styria

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Hi Bill, unfortunately I cannot answer your question regarding left hand drive vehicles. I haven't posted this query on the M100 site - there is just so many hours in the day.....if you know what I mean. I am sure that worn seals must have some bearing on the ability for struts to keep the car at the correct level - I mean, that's the function of the struts, isn't it ? If worn seals are of no consequence, why have struts in the first place ? That's simplifying the equation considerably, but there has to be some merit in that statement.

Also softness - I know that under certain conditions, the right front guard will hit the tyre - and it always seems to be that side. Now, you've got to ask yourself "is it a problem caused by the strut, or is it caused by the pressure cells" ? I am quite convinced that the pressure cells being supplied nowadays are more of the universal type, and not 6.9 specific - I really think that the proper ones are no longer available and they are supplying Ch. 126 units. We all know that the 500s and 560s are far lighter cars with alloy engines, so something has to give. I have checked with the local dealer, and his part numbers equate to the numbers being supplied by the after market companies, so no joy there. I also seem to remember that genuine 6.9 units had a life span of not less than ten years - today's offerings will not last (properly) four years. I was fortunate in recently purchasing Lemfoerder (cells) units, and it will indeed be interesting to see if they last longer than the Febi Bilsteins.

The kit you have does not contain the steel ring. but is correct otherwise. The units that I have had re-made are a little different - more in keeping with today's technology available - well, so I was told. The danger with fitting your kit (and it's fine to use) is that teflon has no memory, so one has to be careful when re-fitting seals. I have fitted two rear replacement struts to Gleaming Beauty, and they are working well, so at least that seems to be a step in the right direction so far. Regards Styria
 
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Oversize

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I have noticed 4248 has a bit of a lean to one side, but I'm not sure which and I haven't investigated why yet. All those leaks will have to be fixed first! LOL! :eek:
 
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Styria

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Hi Mark, what leaks do you have, and also on which 6.9 ? I think you've got about four of them, but am I correct in saying that the one that belonged to Black Hands is the best ? I noticed your other thread concerning claims, but have not yet responded, although I am not surprised at the myriad of "situations" you are experiencing. Regards Styria
 

Helmet

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Interesting thread. I'm of the opinion that the lean has to do with weight distribution. With a spring suspension, differences in weight distribution can be adjusted with larger spring rubbers. With hydraulics I don't know of such an adjustment so if one side of the car is heavier it could be lower on this side. Anybody that owns an update W126 will see this as the differential mount is offset to the LH side making it sit lower in the LH rear , even with hydraulic assisted rear suspension.
 

Oversize

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Styria the lean is on my parts (?) car #4248. It could be a sagged mount (and I know the upper arm bushes are US), but I wonder if the strut could be partially seized and not extending fully? All the dust boots are US, so I wouldn't be surprized.... :eek:
 
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Styria

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Hi Mark, first of all, there are no dust boots on the front struts. What to the eye appears to be a dust boot, it is in fact the rubber bump stop. Front struts have less travel than the rears, and I have my doubts that it would be possible for a strut to seize up. All you have are a well lubricated shaft, a steel ring, a teflon seal (not included in the kit that Bill bought), and an assortment of rubber and teflon seals.

I must admit to having to express my disappointment at the quality of the Air Cells nowadays supplied for the 6.9s. Whilst a well set-up 6.9 suspension wise should have soft suspension, there is not a lot of resistance to 'dive' when applying brakes sharply. Although having said all that, I wonder if 'soft struts' could be the cause of the 'brake dive' ? I guess it can all become a little bit of a compromise. Regards Styria
 

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Ah yes I forgot the fronts dont have boots. Obviously it's been quite a while since I checked any! I'll have to eliminate all leaks and clean it all down to make an accurate assessment of the problem. Perhaps it's low line pressure, or a problem with the front valve? But that's only if all the lines are completely separate. More investigation is needed before I can comment any further, but it is encouraging that a seized strut is unlikely. The system was designed to reduce dive and squat, so if that's happening, I'd suggest there's another problem....
 

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