Mercedes Service Modification

For those that may find this of interest. Back in the '70's, Mercedes produced a special stiffening plate that bolts to the inner guard chassis rail and the steering box itself. It is quite an elaborate arrangement and it would certainly assist in stabilizing an area that is subject to considerable steering forces, especially with a heavy engine like the 6.9.

The design is quite ingenious as it involves no welding and, more importantly, three internal sleeves that pass through the chassis rail prevent the 'squashing' or depression of that chassis rail when one starts tightening up the plate that uses the steering box itself as an anchor as well.

This was a $700.00 part in the '70's, and I am able to have some units made up at a cost of $280.00. Pictures below illustrate the unit




The second picture illustrates the templates that I have made up to cater for:

1) Left hand drive vehicles, and
2) for those that do not wish to spend the asking price.

The templates are available at $40.00 each. Regards Styria

N.B. This modification suits both the 116 and 107 chassis models. At this stage, I have not tried to adapt the plate to109 models.

Would that sit on the other side of the rail?

I mean the rail would be between the box and the plate?

Hi Michel, the rail fits between the box and the plate. There are obviously three long bolts that are secured to the steering box, and a further five bolts and locknuts secure the plate to the outside of the chassis rail.

I have not yet fitted this modification to Gleaming Beauty as I have been saving the original up to now. Whilst I cannot guarantee that it would be beneficial in helping with steering and handling characteristics, it certainly will do no harm. Regards Styria

Dear Styria
So this wasn't the same as the "W107 subframe recall" where someone would book their car into the dealer and they would do it for free?

You actually had to pay the $700 for it to be done?

Hi Des, according to Marshalls in Sydney, the $700.00 covered the cost of the part. Fitting was an extra. I don't know why, and IF, it was considered a service item - perhaps it was optional and I suspect it was as I have never seen this plate at any other time. I got it off a 6.9 that was being wrecked.

Additionally, I am certain that the 107 recall related to subframe, rather than steering components. Regards Styria

Just as an addendum, I have previously advertised this "deal' but with absolutely no success and this surprised me. Probably not much more will happen this time round but, if nothing else, it's been instrumental in mine posting my first two pictures on the discussion board -

Styria said:

Just as an addendum, I have previously advertised ths "deal' but with absolutely no success and this surprised me. Probably not much more will happen this time round but, if nothing else, it's been instrumental in mine posting my first two pictures on the discussion board -

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That's a bit odd, in the past I have chatted to a former Mercedes mechanic who was telling me about the necessity to weld up cracks in the chassis from steering box issues on W114's and W108's, seems to be a common fault.
You can imagine depending on how well the welding is done how good or poor the job is fixed, whereas something like this gives it the load bearing across the box and the chassis, rather than just band aiding it up.

Styria said:

Hi Michel, the rail fits between the box and the plate. There are obviously three long bolts that are secured to the steering box, and a further five bolts and locknuts secure the plate to the outside of the chassis rail.

I have not yet fitted this modification to Gleaming Beauty as I have been saving the original up to now. Whilst I cannot guarantee that it would be beneficial in helping with steering and handling characteristics, it certainly will do no harm. Regards Styria

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I agree Styria, it'll definately do no harm.. Though I can say that after the extensive amount of 'steering' i've done with the track car. For example today I had a skid pan day (solid day of drifting) where the car was on opposite lock most of the day, and if it was ever going to give under stress - it would've been today!!

In saying that, i'll definitely consider adding this bracket in when I do the steering box re-build... it can't hurt.

SELfor50 said:

I agree Styria, it'll definately do no harm.. Though I can say that after the extensive amount of 'steering' i've done with the track car. For example today I had a skid pan day (solid day of drifting) where the car was on opposite lock most of the day, and if it was ever going to give under stress - it would've been today!!

In saying that, i'll definitely consider adding this bracket in when I do the steering box re-build... it can't hurt.

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Maaaaaate.....

I'd get that steering mounting situation checked...

Just in case.....

I am certainly no expert on chassis engineering, but from what I read Manufacturers are constantly striving for increased body stiffness in the interests of safer and more predictable handling. Also, you've only got to look at some performance cars that have adjustable cross braces in the engine bay from one top mount to the other. So obviously, the stiffer the body and less flex, the better the handling ought to be.

With this particular plate being a service item so early in the model's life, one would tend to think that it would have been offered as a modification rather than an attempt to fix a problem. Again, I don't know, but I will certainly fit mine to Gleaming Beauty in due course. Regards Styria

...It would be interesting to hear what the Classic Center had to say, if they could shed any further light on the part.

So is it correct that after being offered as an upgrade that these plates weren't fitted prior to delivery at all on later models, including 6.9's?

As stated ages ago I was surprised to see my 350 had one but none of the 280's I've got here have them. Considering the seemingly thinnish section of of rail and inner gaurd it's a wonder it wasn't applied as a recall. Obviously if they came up with a fix there must have been a problem. I wish I took a closer look at that yellow wrecking 280 to look for signs of stress.

It may become more important as tyres get wider and syickier.

Bill

Oscar, where do I find this thing? Is it under the RH front wheel arch or somewhere else?

Good picture, BTW - which car is it from?

I.

B13 , that's an old photo which was taken for a leaking brake hose not necessarily the plate. The plate just happened to be there, but it shows it up nicely how it's fitted. The plate is on the 350 BTW.

If you haven't got one you'll see just the three biggest bolts I think forming a triangle.

I took this photo just now to give you a better idea. Taken from the trailing edge of the front right tyre looking in. Man that looks grotty under there.

Hi Ossie, 'sneaky' little bugger, aren't you ! I never knew that all along you had one of those mods. on your beloved 350.

Anyway, I am glad that you do, because for a start you have given us pics. of the installed product, which gives every one the opportunity to evaluate the merits or otherwise of this bracket.

As I said, I had never seen that bracket installed on any car other than that particular 6.9 and, I have to admit, that I have never experienced or seen any problems as far as chassis rail breakage or cracking is concerned, with the 116 models.

Heaps of problems on 109's (particularly 6.3's) and what's worse, some of the remedial work or measures taken border on the absolute as far as crudeness of repairs are concerned.


I have heard it said that similar brackets were available for 109's, but it is my belief that once any damage was discovered, it would almost be too late to fit that bracket.As you said, Ossie, something must have triggered MB into introducing this part, but I do not know the exact reason why. Regards Styria

Styria said:

As you said, Ossie, something must have triggered MB into introducing this part, but I do not know the exact reason why. Regards Styria

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It would be an ideal time for someone who has current M100 club membership to contact the classic center and say they are writing an article on the subject and see what information they can provide.

It would make an excellent technical article for the website here.

I wonder if Craig in Turkey is a member?

Michel said:

I wonder if Craig in Turkey is a member?

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Craig has mentioned in the past he has visited the MB archives, but unsure about his M100 membership status, he does post over there.

Good pics Oscar!! I was trying to picture how they were installed...

Will scope out the silver beast tomorrow and see what the status is. So it firms up through the chassis and connects to the right side of the steering box??

SELfor50 said:

Good pics Oscar!! I was trying to picture how they were installed...

Will scope out the silver beast tomorrow and see what the status is. So it firms up through the chassis and connects to the right side of the steering box??

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Here's another pic to confirm what was stock. Just those three big bolts which are clearly visible. They go through to the steering box. The first time I saw styria's plate I had no concept of how it was fitted nor did I realise I had one until I was doing the brake lines last year and recognised the pattern of bolts. So not sure how the smaller bolts secure the plate to the engine wall/inner guard, I'll leave that to styria, I haven't had a good look from the other side let alone remove the 350's steering box.