Alternator Pulley Removal

[emerydc8]

I just ordered a reman Bosch alternator from FCP Euro (which came in record time BTW), and the WIS says to use a 10mm socket with "internal serrations together with reversing ratchet to hold the shaft." The Torx T-50 seems to have some play in it. Before I go ahead and strip it, is this the right tool for the job? I'm a bit puzzled by the WIS reference to a 10mm socket with internal serrations. Maybe there are metric Torx tools as well?

 

[emerydc8]

Nevermind. On further research, it looks like the inside of the alternator shaft is a 12-spline 10mm flange -- not a Torx which is only 6-spline. Mac tools makes one (SC90 10mm). I just bought one on Ebay for $25.

12-spline flange


The 12-spline flange screw drive has twelve splines in the fastener and tool. It consists of 12 equally spaced protrusions, each with a 60° angle. It is achieved overlaying 4 equilateral triangles, each one rotated 30° over the previous one. The spline drive was part of the obsolete, U.S-designed Optimum Metric Fastener System and was defined by ASTM B18.2.7.1M, which was withdrawn in 2011,[70] making the spline drive obsolescent. Spline drives were specified for 5, 6.3, 8, 10, 12, 14, 16, and 20 mm size screws.[71] Its primary advantage is its ability to resist cam out, so it is used in high-torque applications, such as tamper-proof lug nuts, cylinder head bolts, and other engine bolts.

 

[gerryvz]

Yes, thats an XZN or “triple square” type of tool. It’s a good idea to have a set of them on hand.

 

[emerydc8]

Yes, thats an XZN or “triple square” type of tool. It’s a good idea to have a set of them on hand.

Thanks. I see the cheapo sets on Ebay, but what do you have? I know it's not from China.

 

[gerryvz]

I have only a few items, mainly for cylinder head bolt removal, and these are the factory MB (Hazet/Stahlwille) sockets. Fortunately (and similarly to female Torx) these types of fasterners don't pop up much on our old Benzes, but you have to be prepared in the few cases they do.

I believe that the M104 and M119 cylinder head bolts and E500E rear-axle half-shaft bolts use XZN, and possibly a couple of bolts on the rear suspension.

 

[gerryvz]

You can get them at places like Home Depot:

Capri Tools XZN Triple Square Bit Socket Set (10-Piece) CP30030 - The Home Depot

The XZN triple square bits in this set are made from heat-treated S2 steel alloy to withstand long-term use, the sockets are composed of chrome-Vanadium to provide optimal strength and durability. The

www.homedepot.com

Or Amazon:

Amazon.com: LEXIVON XZN Triple Square Spline Bit Socket Set, Premium S2 Alloy Steel | 10-Piece European Style M4 - M18 Set | Enhanced Storage Case (LX-145): Home Improvement

Amazon.com: LEXIVON XZN Triple Square Spline Bit Socket Set, Premium S2 Alloy Steel | 10-Piece European Style M4 - M18 Set | Enhanced Storage Case (LX-145): Home Improvement

www.amazon.com

Or Northern Tool:

Klutch Triple Square Bit Socket Set 9-Pc. | Northern Tool

The Klutch® 9-Pc. Triple Square Bit Socket Set features chrome vanadium sockets and S2 steel bits for strength and durability. Inc...

www.northerntool.com

This is a very nice set:

Robot Check

 

[emerydc8]

Thanks. Il‘ll stop by Home Depot today. Aside from the 12-pointt triple-square, Allen, and Torx (male and female), what other unusual drivers do these cars use? Are there any star bits?

 

[gerryvz]

Check your Home Depot online to see if they have the set in stock -- most stores around me DO NOT. I think the ones on Amazon are better quality, anyway.

The power steering reservoir uses Female Torx bolts. And modern MBs are using more and more stuff like Female Torx, Torx and XZN.

And I am seeing more and more bolts on our cars being superseded to FT, and T bolts from their original factory Allen bolts -- the fan clutch center bolt is a perfect example of this. So when I find these original bolts (like the fan clutch bolt, which is easily stripped out) in good condition, I like to "hoard" them.

 

[emerydc8]

You’re right — Home Depot did not have them in any store in town, so I ordered through Northern Tool along with an extra female Torx set.

 

[emerydc8]

While perusing through the tool section of the WIS I found the head bolt tools GVZ referenced. I ran the part numbers through mboemparts and the price is listed ($30-$40). Although I have a set now and a Mac Tools M10, if they really are available I wouldn't mind having the MB M12 tool in case I ever had to re-torque a head gasket. I don't think I'd trust the Northern Tools I bought to do this.

It is interesting that this tool has six different names:
Triple Square
Double Hexagonal
Bihexagonal
XZN
12-spline flange
Spline drive

 

[gerryvz]

Yes, if I remember correctly they specify two different lengths of the factory XZN socket for head bolt removal on the M104. I think you can get away with just one size, but I got both of them.

For head bolt work, I WOULD NOT rely on cheap XZN tools from Northern Tool, Harbor Fright, Amazon or perhaps even Craftsman (nowadays). I would go ahead and make the investment in the factory socket(s), which are made in Germany and are very strong and up to the task of torquing head bolts. If you could find an aftermarket Hazet or Stahlwille socket (essentially the same ones as MB brands), those would be fine, as well.

For this critical job, not a good idea to cheap out on the tools. They are put under A LOT of stress with the angle-torquing that the M104 (and I presume the M119) has.

Fortunately the M117 uses more conventional Allen-keyed head bolts -- not quite as esoteric as the M104 and M119. And phased torquing -- no angle torquing.

Cheers,
Gerry



Here is the "long" version of the factory XZN socket for the M104/M119. I can't put my hands on my "short" version -- I think I may have loaned it to someone when I lived in Texas (something I **NEVER do) and never got it back.

 

[gsxr]

I can't put my hands on my "short" version -- I think I may have loaned it to someone when I lived in Texas (something I **NEVER do) and never got it back.

You mean this one?

 

[gerryvz]

You mean this one?



View attachment 99668

So it was you that borrowed it. Can I have it back, please?

 

[gsxr]

So it was you that borrowed it. Can I have it back, please?

IIRC, you borrowed it from me, and sent it back promptly - thanks! Maybe you forgot to buy your own?



$35 from Napster:

Screwdriver 119-589-00-10-00 | MB OEM Parts

119-589-00-10-00 - Screwdriver

www.mboemparts.com

 

[emerydc8]

I ordered both M12 tools: Screwdriver 119-589-00-10-00 | MB OEM Parts and Socket 617-589-00-10-00 | MB OEM Parts

I wonder if the people at Naperville ever wonder why someone in different parts of the country would order, on the same day, a tool they probably haven't sold in years. They're probably too swamped to even notice.

Gerry: Do you remember if the M104 head uses the M10 tool or just both M12 tools?

 

[Kyiv]

I wonder if the people at Naperville ever wonder why someone in different parts of the country would order, on the same day, a tool they probably haven't sold in years

I've noticed this paradox is omnipresent across many cases in retail. I continually experience it my current business and observed it all the time in my past employment at certain retail operation. For unexplained reason multiple people purchase a specific SKU (e-commerce), that is a seldom sale, within hours or sometimes even minutes of each other. Or, after a quiet, no customers for 40 minutes period (physical retail), a cohort suddenly shows up, as if brought by a bus. We are clearly living in a simulation

 

[gerryvz]

I think the M12s. Check my HOW-TO.

 

[emerydc8]

Hazet and Stahlwillie M12. At least some things are still made in Germany.

 

[gerryvz]

I just took delivery of my short head bolt socket in my Naperville order yesterday. Good stuff.

 

[emerydc8]

I just took delivery of my short head bolt socket in my Naperville order yesterday. Good stuff.

Is that the one Dave stole from you?

 

[gerryvz]

I wasn’t going to say anything ....

 

[nocfn]

Actually, I have spoken to Renee and Bob in the past to alert them to runs on specific parts based on "forum fodder" and in some cases they have ordered them just to be sure that they could supply. Not a gross, but a consideration of the value we have embedded in our Naperville relationship. We often hear the gripes, but there is plenty they do for us behind the scenes to try and head up the order potential.