Need to pull a 126 differential cover. In the lower left hand corner is an arm-support with an upper/lower rubber bushing. A bolt goes up thru the bottom of the lower bushing.

A Torx T55 bit seems to fit fairly well; however, the 126 CD-Rom refers to it as "serrated". Reading through other posts here, it seems there's a difference between TORX and SERRATED. The metal on the bolt head appears to be VERY soft. I've tapped it a few times with an impact driver to loosen it and have tried the gently loosen it with a Torx T55. It's not budging.

Would anyone know the correct socket to use here? Thanks for your time.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

This bolt as well as many head bolts use a SPLINE style head. The sizes are metric, M10 & M12 are the common sizes. Snap-on, Mac, & Hazet all have these spline sockets.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
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44 years foreign automotive repair
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Retired Moderator

This same type of bolt head is used on (older definitely, maybe current) Volkswagen CV joints. It may be easier to source it at a local parts store if you describe it as such.

Good Luck

Doc/RTH

Thanks for your help. Lisle Tools makes a set that I just saw at a mass-marketer.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

Just out of curiosity, which “mass marketer” did you find them at? I’m always looking to stay current with good sources.

Thanks

RTH:

I saw them at Pep Boys. Cost was around $10 for a set. I'll reply back to this post tomorrow with the actual Lisle part # after I make the purchase.

Regards.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

The SPLINE style head that DOC referenced above is also available at Pep Boys. The tool mfg is Lisle Corp. Part is named "12 point bit set". Part # 60750. Viewable at their WEB site:

http://www.lislecorp.com

Click on Special Tools -> Catalog -> Fastener

Lisle tools are widely distributed in the U. S. and Pep Boys is certainly not your only choice. Stahlwille, Hazet, Snap-On; Mac also carry this item.

In closing, the 12 point bit is also known as "triple-square" and "XZN". A sales rep at Baum Tools told me that MBs use TORX, XZN, RIBE in addition to traditional bolt/nut patterns.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"