S Class (W221) Wheel Studs

[PaulMason]

I must admit, I feel somewhat ashamed asking this question as seems so daft.......but here goes. I went to take the wheel off my S320 CDi (2009, W221, 18 inch wheels) as the wheel speed sensor has failed, got the locking wheel bolt key from the boot and then found the studs on the car (4 on each wheel in addition to the locking one) to be a design per the below pic with a curious double hex pattern. I initially assumed that they were a hex bolt with a decorative cover, but after quite some time of trying to remove the "cover", thought perhaps it wasn't a cover (though each cover could be twisted a couple of degrees each way). The wheel brace in the boot was a 17mm so tried it onto the bolt and it gripped, so I took them off with a long nose 17mm hex socket and breaker bar. They then were a bit of a pig to get out of the socket and I seem to have slightly damaged them. However, they went back on and I torqued back to 150lb ft so its all good (and I managed to fit the new speed sensor and fix they ABS/EPS light issue). However, I still feel that I have done the wrong thing and want to do it right so I am going to buy some new ones and replace the 4. Before I do I have a couple of questions and seek your wisdom:

1) Is the end of the wheel stud indeed a decorative cover which should be removed (even with them off the car, I couldn't) - if so, is there a special tool/method?
2) If they are not a decorative cover, is there a special socket that should be used to removal/refitting?

 

[tode]

The stainless steel head is a part of the screw and should not be removed.

I always use a standard six-sided 17mm socket on them and have no problem. I would imagine that a twelve-sided socket might be a tight fit, though . . .

 

[moakesr]

I bought one of these

HAZET 905SLG-17 86 mm Special Profile Impact Socket - Multi-Colour : Amazon.co.uk: DIY & Tools

Shop HAZET 905SLG-17 86 mm Special Profile Impact Socket - Multi-Colour. Free delivery on eligible orders of £20 or more.

www.amazon.co.uk

 

[PaulMason]

The stainless steel head is a part of the screw and should not be removed.

I always use a standard six-sided 17mm socket on them and have no problem. I would imagine that a twelve-sided socket might be a tight fit, though . . .

Thanks Tode, a big part of ownership for me is learning and now I know thanking you. I suspect I have a) old and very tight studs hence why they are looking a little second hand now (I had to use way more force to remove than to replace at 150lb ft) and b) been a bit cack handed. Now I know a new set of studs can be ordered for a modest sum

 

[PaulMason]

I bought one of these

HAZET 905SLG-17 86 mm Special Profile Impact Socket - Multi-Colour : Amazon.co.uk: DIY & Tools

Shop HAZET 905SLG-17 86 mm Special Profile Impact Socket - Multi-Colour. Free delivery on eligible orders of £20 or more.

www.amazon.co.uk

moak
View attachment 131299

Thanks Moakesr. I think I have an old set of sockets which have the 12 sides design so I'll hunt them out, if not, I'll buy one of these. Thanks for the tip

 

[giusepppe]

Thanks Moakesr. I think I have an old set of sockets which have the 12 sides design so I'll hunt them out, if not, I'll buy one of these. Thanks for the tip

If you socket is hard to get on, its usually because a hammer gun has been used to tighten the bolts when fitting new tyres, they do not ensure the socket they use is fully on the bolt, they leave a heavy burr on the head of the bolt, and its a right B to get the standard wheel leaver on let alone a socket, also the torque setting is 150 Nm, not lbs/ft.