Check your steering coupling

[John Green]

The MB Spares has recently removed this coupling and shaft assembly from a W123. we were surprised to see it and have since looked at a few other cars and some have small cracks in them. This the coupling in the middle of the column, you need to remove the trim under the dash to check it. So this post is a service to all W123 owners and will be made a sticky so it stays at the top of the list.

Go and check your steering column coupling. NOW.

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[pastelgrey300D]

Interesting that you have had a few near failures - it's a part that is very well protected from the elements etc. Is this more of an issue for cars with high kms or that have done country driving? Or is it a case of the rubber just aging?

[John Green]

Interesting that you have had a few near failures - it's a part that is very well protected from the elements etc. Is this more of an issue for cars with high kms or that have done country driving? Or is it a case of the rubber just aging?

Car it came from was a well serviced car with 260k on it, spent most of its life in Sydney, so at a guess not much different to many other W123's out there.

[mathuisella]

Interesting that you have had a few near failures - it's a part that is very well protected from the elements etc. Is this more of an issue for cars with high kms or that have done country driving? Or is it a case of the rubber just aging?

Car it came from was a well serviced car with 260k on it, spent most of its life in Sydney, so at a guess not much different to many other W123's out there.

fire truck, that's why it spend half it's life travelling up and down parrammata road, twice a day :/

I swear the idiot with no foresight who blocked the completion of the M4 all the way into the CBD because of "highway noise" regrets it now..... instead of some 'woosh' noise with the sound dampeners/walls you hear everything from bicycles to 18 wheeler trucks going over every pot hole...

and they cannot close the road and repair it because it's the only west bound way into the city.

And the logistics that it crosses a few councils so they blame each other for the roads faults.

[DirtyFingernails]

Finally inspected my steering coupling today. Looked good all around it, no cracks, phew! :occasion5:

[300TDT]

Is this a DIY job inside the cabin?

[Tony From West Oz]

Is this a DIY job inside the cabin?

Not exactly. It is a DIY job under the bonnet adjacent to the firewall.

[300TDT]

This is under the dash, isn't it?

Lower photo. Point 4. Seems to be a simple unbolt job?

Any links to DIY info if not in FSM?

[John Green]

There are two joint, one under the dash and the other where the steering column joins the steering box.

[300TDT]

Are they both 1234620346?

There are two joint, one under the dash and the other where the steering column joins the steering box.

[Tony From West Oz]

When I put the turbo into the 300D, I found that the exhaust was very close to the steering box. There were no issues though, until I removed it for installation in the 280CE. I found that the flex coupling for the steering had degraded with the rubber melted around its periphery, mainly in the "straight ahead" position.
The 280E had a heat shield there to protect the coupling from exhaust heat.
I retained the heat shield when the OM617A went in.

[Astro-Benz777]

Is this just an issue that effects the W123 series or also the W116/126 series that ran concurrent?
The reason I ask is that I know the W126 coupling looks very similar (generally speaking) however is located more inside the cabin under the dash/above the pedals as opposed to where you described the W123's was located.
I guess you couldn't conclusively answer what the cause was, whether failure of the part from heat due to location, age/general wear, possible previous front end collision, part material flaw etc etc really.... because that might eliminate the possibility of it being an issue that effects other models.
Nonetheless, the next time I'm tinkering in that area of my car, you can be dam sure I'll be checking it out.
What would be the result of "Catastrophic Failure"?
(Stupid question I guess but I can't seem to picture it)