W169 Steering wheel retaining nut

[David Richardson]

I need to remove the steering wheel of my A class in order to replace the wiper stalk & have come across a small problem.

Could someone tell me the size of the allen key that fits the centre nut, it looks as if it could be 8.8mm but then I've never come across such a size before.

I could just buy a cheap set of allen sockets but would prefer to buy 1 quality product

anyone with such knowledge ?

 

[ZZZZ]

David, the WIS doesn't give the bolt size (as far as I can see), just the torque:

 

[David Richardson]

Thank you David,
I appreciate your help & wonderful pics.
It could be that I need to buy a small set of allen sockets

David

 

[area51]

I think that 8.8 refers to the tensile strength of the bolt.

(Referring to EPC) the steering wheel bolt is the same as on my W168, so I think that you will need a 10mm allen key socket and a suitably long bar/ratchet.

The torque setting is not huge but the thread lock that Mercedes use is quite good! The bolt shouldn't be re-used according to Mercedes.

 

[ZZZZ]

The bolt shouldn't be re-used according to Mercedes.

How crucial is that? I only just noticed that on the above worksheet myself.
When Jack fitted my newly re-trimmed steering wheel he used the same bolt.
Should I be worried?

 

[Trev1964]

I've reused mine as well.

 

[David Richardson]

I have heard a similar point before when fitting injector retaining clips & something like stretching the threads,
David if your steering wheel is firm then I wouldn't worry & I'll be using the same nut on my car

 

[Frosty149]

I have heard a similar point before when fitting injector retaining clips & something like stretching the threads,
David if your steering wheel is firm then I wouldn't worry & I'll be using the same nut on my car

I'm still waiting for the sad joke to surface....

 

[KennyN]

The wheel retaining bolt on the CLS was a mare to remove , it was held very securely with the locking compound.

It was a two person job , one to hold the wheel and the other to loosen the bolt.

With the above in mind then maybe one "quality" socket may be the best option , rather than a cheapo set, as if you chew up the hex then you will be in trouble.

Kenny

 

[area51]

How crucial is that? I only just noticed that on the above worksheet myself.
When Jack fitted my newly re-trimmed steering wheel he used the same bolt.
Should I be worried?

Not 100% certain but I think the reason for renewing the bolt is that it has thread locking compound pre-applied.

Perhaps the bolt can be re-used with a suitable good quality thread lock, Loctite or similar?

The bolt is tightened to 80Nm and (from memory) has a tapered seat that will act as a locking device.

Hope this helps

+1 for a good quality socket

 

[star]

I need to remove the steering wheel of my A class in order to replace the wiper stalk & have come across a small problem.

Could someone tell me the size of the allen key that fits the centre nut, it looks as if it could be 8.8mm but then I've never come across such a size before.

I could just buy a cheap set of allen sockets but would prefer to buy 1 quality product

anyone with such knowledge ?

10mm

 

[ZZZZ]

David if your steering wheel is firm then I wouldn't worry & I'll be using the same nut on my car

Great, thanks. There's not a hint of play in the steering wheel, so should be OK I guess.

Not 100% certain but I think the reason for renewing the bolt is that it has thread locking compound pre-applied.
Perhaps the bolt can be re-used with a suitable good quality thread lock, Loctite or similar?

I wish I knew that - pretty certain, Jack didn't apply any, and I do have a very good one, I could have brought with me ...

The bolt is tightened to 80Nm and (from memory) has a tapered seat that will act as a locking device.
+1 for a good quality socket

Your memory is spot on! It's actually on the WIS page screenshot above

Jack had a very nice high quality socket (and other tools), so that's fine -looking at the head here, it's perfectly intact:

I've reused mine as well.

Good to know, thanks.

I'm sure it'll be alright for now, but for the next time, I'll get a new one from Mercedes, to keep in my spares box

 

[umblecumbuz]

... I'm sure it'll be alright for now, but for the next time, I'll get a new one from Mercedes, to keep in my spares box

If the steering wheel comes off due to the re-used bolt, will you need a spare?

Umble

 

[Steve@Avantgarde]

It is reusable, add a small amount of loctite.

If the bolts need to be thrown away, the WIS instructions will tell you, in this instance above, there is no such instruction.

 

[mercedes13156]

I had to replace a steering wheel position sensor recently and my wife came out with a cuppa while I was in progress. She picked up the replacement sensor to see what it was. After getting it back and ready to put back together I thought I had the sensor all lined up and taped to go back in. Unfortunately not. I accidentally put it in 360 degrees out, (a whole turn to the left. i think it was to the left. Bear with me for the rest of this). Once assembled it gave me an error for the ABS / BAS / ESP plus a few other things.

On checking the steering angles it turned up as "Not Initialised" and read 360 degrees instead of zero while the wheels were dead ahead. On full lock it should go to about 570 degrees positive on the right and -570 to the left. It was reading about 730 degrees on the left and about 210 degrees on the left. (give or take a bit)

I stripped it all out again turned the sensor a full turn to to the right, popped it all back together and no faults.

Be careful out there!

 

[David Richardson]

Thanks to all who have helped on this one, given the thought that if I screw up I may need to have the car reset on a star machine
at a cost, I will leave the job until the end of the month & take my car to my local indie at Mercare in Plymouth and pay him a couple of hours labour

Dave

 

[brianbrian]

As said, it will take two strong people, one to undo the bolt, I use a 3/4 inch bar with a 10mm socket,the one holding the steering wheel with one hand needs to have a club hammer so he can give the top of the socket a whack when you are undoing the bolt,this will crack it.

 

[brianbrian]

Grr so angry. Do not no how many steering wheels I have taken of with air bags. Putting it all back done the last screw up of the two on the air bag and with drew the drive when the socket came of and is still in the steering wheel. You can buy the tool where the socket and drive are in one

 

[brianbrian]

Hands up, how many this has happened to.