6.9 engine mounts

[Styria]

I had always been aware that 6.9s had engine mounts that carried a different part number to those used for the 450 model range fitted with the M116 and M117 engine range, and there was of course quite a difference in cost between the 450 and the 6.9 units - in fact, the price is probably double nowadays, with 6.9 units retailing from the dealers for about $320.00 each.

It's been a well known fact that quite often 450 units are used instead of the proper ones - obviously on account of cost. I had the opportunity the other day to compare a new genuine 6.9 mount with a brand new 450 as well as a worn 450 mount. Furthermore, I had saved an old 6.9 unit from many moons ago and the differences were quite remarkable.

I can't make any comment concerning various rubber compositions between different mounts, but I can certainly talk about size. Without a doubt, the 6.9 unit carries the most "meat" - in fact to the extent that the old 6.9 unit I had on hand again had more rubber than even the new 450 mount (M117). I won't even mention how the old 450 unit compared in size.

So, the upshot is that, really, one should fit genuine 6.9 units - they are obviously designed for the M100 - 6.9 engine with its additional weight. I will take pictures, but will not post them until my computer is back up to broadband speed. Presently I am limited to dial-up, or the equivalent, and it is painful. Regards Styria

 

[s class]

The correct mounts for 6.9 are 123 241 14 13 (x2) , while for a 4.5 they are 116 241 28 13 or 123 241 16 13 for right, and 116 241 29 13 or 123 241 11 13 for left (note - left and right is in this case I think for LHD cars - perhaps its reversed for RHD cars???).

Autohaus listed 123 241 14 13 for under US$40 I think, and I ordered a pair together with a whole lot of other stuff for the Webasto block preheater project car. I then a day or so later received an email from Autohaus indicating that 123 241 14 13 was in fact unavailable, and they have subsequently removed them from their on-line shop. THis is most annoying as I was banking on that price to get this project completed within the owner's budget.

Anyhow, its also interesting that the 6.9 mounts have a 123 number - this suggests that they must be shared with at least one variant of the W123 family. Anyone know which one? if they are indeed a common W123 part, there must be some demand, in which case Autohaus' inability to supply is all the more annoying.

 

[Fotografa]

The correct mounts for 6.9 are 123 241 14 13 (x2) , while for a 4.5 they are 116 241 28 13 or 123 241 16 13 for right, and 116 241 29 13 or 123 241 11 13 for left (note - left and right is in this case I think for LHD cars - perhaps its reversed for RHD cars???).

Autohaus listed 123 241 14 13 for under US$40 I think, and I ordered a pair together with a whole lot of other stuff for the Webasto block preheater project car. I then a day or so later received an email from Autohaus indicating that 123 241 14 13 was in fact unavailable, and they have subsequently removed them from their on-line shop. THis is most annoying as I was banking on that price to get this project completed within the owner's budget.

Anyhow, its also interesting that the 6.9 mounts have a 123 number - this suggests that they must be shared with at least one variant of the W123 family. Anyone know which one? if they are indeed a common W123 part, there must be some demand, in which case Autohaus' inability to supply is all the more annoying.

The reason they are different left to right, is that the right ones take more torque from the engine. It is possible, and a lot of vendors advertise as such, to use the left ones on both sides. But I wouldn't. It's not reversed for RHD cars.

After cross referencing the part numbers, I can safely say no W123 used the 6.9 mounts.

 

[Fotografa]

The reason they are different left to right, is that the right ones take more torque from the engine. It is possible, and a lot of vendors advertise as such, to use the left ones on both sides. But I wouldn't. It's not reversed for RHD cars.

After cross referencing the part numbers, I can safely say no W123 used the 6.9 mounts.

Oh, and for future reference, best price I've found, for OEM (not aftermarket) 6.9 mounts is about USD$70.00 each.

 

[WGB]

After I changed the timing chain on my 6.9 the power output changed quite dramatically and the aircon tubing vibrated on the side frame with full throttle take-offs.

Purchased all new mounts from autohausaz and here are photos of new and old mounts.



Bottom view



Top view



Transmission mount

I wished I had changed the RH mount while I had the airconditioning compressor out as space is tight and here is a picture of how I tightened the LH mount with long extensions and a universal joint.



Best of luck and make sure your lifting gear can handle a 6.9 motor.

Bill

 

[Styria]

Quite an interesting discussion, and it is necessary to raise some points for clarification purposes. First of all, whilst I stand to be corrected, I have serious doubts that 6.9 mounts would be produced for the 'after market' trade - I think that the turnover would just be too small.

However, that does not mean that you cannot obtain those from the very same after market suppliers, but I am unable to tell where they would be sourcing them from. This sort of situation does occur with certain parts, such as the shackles for the rear anti sway bars, that once again seem to have no alternative manufacturer.

The information that I have is as follows: Marshall Motors are able to procure the engine mounts for $280.00 plus ex Singapure. One of the after market suppliers I have a contact with have been able to source TWO ONLY Australia wide at $195.00 plus for each one. That's my price, and if I had a quick sale, I'd still need to levy a margin of 10% on top of those figures - anything less, and you'd have to question the rationale of purchase and re-sale. If you don't have the privilege of an immediate sale, the extra 10% would be quite insufficient. It was also pointed out that, really Michael, you ought to buy them - there was likely to be none further available from after market sources after they went. I thought hard - $400.00 and how long would you have them ?....hmmm....

As it was, I had two units on hand that I had bought some two to three years ago - I no longer recall what I paid for them, but I onsold them for $195.00 each, all inclusive. In my view, a very fair deal.

S-Class and Fotografa - your observations are important. The question I have of Shayne and the quoted US price of about $US70.00 - is that your buying price as well as retail price, say to someone like my self or anyone else for that matter or would you need to mark them up by a certain percentage ? Regards Styria

BTW - those rear shackles at about $400.00 each in Australia - I can now supply them on an exchange basis, rebuilt units at $80.00 each. Expensive problem solved.

 

[WGB]

I purchased mine from AutohausAZ.com in February 2008 for US$38 each part no 123 241 141 3 - x2 and that is the one shown in the photos.

I paid US$14 for the transmission mount and I see it is still stocked for US$18.45

Pity that Autohaus no longer sell them - sounds like I was lucky.

Bill

 

[Styria]

Hi Bill, thanks for your illustrations as they demonstrate, and confirm, that you have in fact fitted the correct 6.9 mounts.

One would to some extent have to be concerned as to the fate of future supplies. Once you leave matters in the hands of Mercedes Benz, and the after market suppliers for some reasons can't get a look in, price increases could well reach the rampant stage. One only has to look at prices charged by Mercedes Australia for 6.3 mounts - close enough to a thousand for the two. It's quite scary, and again after market will not be able to help you.

So let's keep our fingers crossed. Regards Styria

N.B. Sorry everyone, I did not sign out as one of the Moderators.

 

[TJ 450]

The 6.9 mounts seem to be a much harder compound than the others. This makes sense, as it's also the heaviest engine on this type of mount.

As an example, I can move my 450's M117 on its mounts by hand... you can see them compressing. Those mounts are a year and a half old. On the other hand, I cannot move the M100 at all... that's on the brand genuine mounts. They are seemingly rigid.

I purchased the last remaining mount from AutohausAZ some months ago. It was in fact a genuine Mercedes part. It is now in my spare parts repository, as I ordered a pair from the Classic Center USA and they were not particularly outrageous in price. If you enquired at one of the dealers here in Australia, they would easily be in the $150- $350 price bracket.

I would not fit the versions for smaller engines as they'll just get squashed by the M100.
Not that I'm suggesting you would do that, Styria.

Tim

 

[Styria]

The 6.9 mounts seem to be a much harder compound than the others. This makes sense, as it's also the heaviest engine on this type of mount.

As an example, I can move my 450's M117 on its mounts by hand... you can see them compressing. Those mounts are a year and a half old. On the other hand, I cannot move the M100 at all... that's on the brand genuine mounts. They are seemingly rigid.

I purchased the last remaining mount from AutohausAZ some months ago. It was in fact a genuine Mercedes part. It is now in my spare parts repository, as I ordered a pair from the Classic Center USA and they were not particularly outrageous in price. If you enquired at one of the dealers here in Australia, they would easily be in the $150- $350 price bracket.

I would not fit the versions for smaller engines as they'll just get squashed by the M100.
Not that I'm suggesting you would do that, Styria.

Tim

Hi Tim, I am just not quite sure what to make of your last sentence. However, please allow me to put it this way - if I did, I wouldn't be the first one and, in all probability, not the last one either. Regards Styria

 

[WGB]

The clearance issues with a "squashed" mount were related to the air-con tubing on my car. Even then the mounts were not exactly worn out and it would have been possible to re-route the pipework.

I am assuming that others have totally knackered mounts.

If softer mounts were used and there were no drivetrain to chassis contact points it would depend on whether the engine jumped around on idle too much or whether the engine would flex on it's mounts too much under high power loads.

Bill

 

[Oversize]

I noticed that Red Bull seems to have a partially crushed A/C pipe just behind the compressor, as well as other clearance issues. I suspect the mounts have been replaced with the incorrect type and it's no surprise they're stuffed now. I found the following on E-bay. Thoughts??

http://www.ebay.com.au/itm/190484996142?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

 

[Styria]

I noticed that Red Bull seems to have a partially crushed A/C pipe just behind the compressor, as well as other clearance issues. I suspect the mounts have been replaced with the incorrect type and it's no surprise they're stuffed now. I found the following on E-bay. Thoughts??

http://www.ebay.com.au/itm/190484996142?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Well Mark, who knows - I certainly don't have an answer for you. It's not the sort of job you do with your eyes closed, so you would like to think that the part you're fitting is going to last the distance - about eight to ten years max. Regards Styria

 

[WGB]

It's an awkward job but not impossible to do and I would try the cheaper mounts and see what happens.

My autohausaz ones have held up with no problems so far.

Bill

 

[Oversize]

I'll be pulling the engine and trans out anyway so they should be easy to change then!

I'd heard (on the M-100 site I think) that someone converted 6.3 mounts to the later hydraulic type! Or it could've been on a 600.... I think it required chassis mods and due to the lack of room, it wouldn't be viable on a 6.9.

 

[WiSeGuYY]

Hey GODFATHER & BILL , i'm not an expert but i'm sure life expectancy for the mounts have something to do with type of roads and driving, bumpy roads and off road envairoment deeply effect the life span of the engine mounts so as heat . it looks very small item but the fact of negtive effect on engines that the mounts are worn are huge.

REGARDS

TAREK