Hi All,

Finally, I got myself to replace the harmonic balancer on my 2000 C280 (I got a new balancer from Phil a long time ago). The old balancer is on the verge of an "explosion" so I really need to do it now.
Got a M17 Allen wrench from my friendly neighborhood AutoZone for the nut that holds the pulley. I was pleasently surprised how easy it was to remove the fan (no tools required). Now, the problem is counterholding the pulley. I know that there is a special tool from Mercedes out there, but is there another way to do it (before I get my welder out and make a wrench )?

Thanks in advance for any reply.

One more thing:
Is there an easy way to switch the climate control's and the instrument cluster's display to show temperatures in Celsius?

Greg,
A couple of points from a professionl MB mechanic. First of all do not attempt this job with a tool made in China or Taiwan. These tools are made of hardened butter. Once you round out that allen, you are screwed. Secondly the bolt is secured with blue Loc-Tite so heating the bolt with a smoke wrench will melt the Loc-Tite, but don't heat too mch or you will damage the front seal. Thirdly a good quality 1/2 inch impact will make the job a piece of cake if you have the room. ML320s have lots of room, but I don't know about your model.

Peter

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Auto Zentral Ltd.

Thanks for the pointers. I'll try to heat up the bolt (carefully). The Allen from AutoZone holds up pretty well. I have tried with my impact wrench (max torque 310Nm (230ftlbs)) as it fits (barely), no luck, I have tried to hold the pulley and applied about 1000Nm to the bolt but it won't budge.

Greg:

You really need to check out the last page of this thread. One guy made a really durable looking hold down tool. If you don't want to make your own, get one from Baum Tools; I believe they have them. When I did mine, there was no sign of Loctite from the factory. The dealer said it's torqued to 450 ft-lbs at the factory (mine is an ML). A 1/2 inch Ingersoll impact wrench did not budge the bolt. You need a good hold down tool and a 5 foot cheater bar (4 feet is too short, really). Your Auto Zone socket will hold up just fine. I would reassemble with Loctite, however. The dealer said his guys torque it down to 250 ft-lbs and add a tug--like you and me, his guys don't have torque wrenches that can measure 450.

Do a search; most of your questions have already been answered on the above mentioned thread. Good luck!

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Lenny

There are only three sports: bullfighting, motor racing and mountaineering; all the rest are merely games. --Ernest Hemingway

'10 GL550/'04 BMW 545/'99 BMW 323/'98 ML320/'87 VW GTI (race)

I remembered that thread and was looking for it but could not find it. It used to be pinned as the first...

Thanks - I am off to weld some metal to create a wrench...

G.

Greg,
Again before you go through all that trouble, try heat and impact. I used a top quality impact and leaned on it. it wouldn't budge. I applied a little heat with my smoke wrench and it buzzed right out. I saw evidence of blue loctite. Also make sure the allen socket doesn't say Taiwan or China on it anywhere. The melted loctite trick works on steering wheels, load leveling struts, tailgate shocks and many other apps.

Good luck,
Peter

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Auto Zentral Ltd.

Blue loctite is confirmed.


I spent my morning to run around rental stores for a chain wrench (as was suggested by a member). Finally I got one that was the right size (with a 4 1/2 inch face) was $18 for the day. REmoved the bolts from the waterpump pulley to have some more room, put the wrench onto the pulley (damage did not matter anymore). Put my allen with a reinforced Craftsman 1/2 bar and a 5 foot 3/4 pipe on the bolt. I pushed thechain wrench with my feet and pulled the pipe with my hands (kind of a back breaker). Finally the bolt moved and I have turned it about 90 degrees. Then I put my 630ftlbps impact at it and it still did not do anything (after loosening up the bolt! ). So back to the back-breaker and opened it all the way up.

My new HB runs like a charm...

Thanks for all the help!

Hey just wanted to give my 2 cents. For one the torque is 150 ft-lbs and then 90 degrees. It sure sounds like you went through a lot of trouble. The dealer only should charges about an hour for labor (parts extra$$$ of course).
It is also a good idea to replace the bolt (replacement bolt is a 27 mm hex bolt) do to it being a stretch bolt and all.

I have seen those specs too. Tell me how you are going to measure 90 deg. in that limited space. I just reuse the old bolt. After all the bolt has never failed. Only the balancer fails. Torque to yield bolts have been out for more than 2 decades. Why didn't they use one in the original application. I think the world is starting to suffer from way too many engineers.

Peter

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Auto Zentral Ltd.

This is the only place you're going to get it for the later model Benzes!
As an engineer myself, I can't agree with that statement. I will say we'd be better off if more of us brought common sense along with our book learning! Lawyers on the other hand....

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Lenny

There are only three sports: bullfighting, motor racing and mountaineering; all the rest are merely games. --Ernest Hemingway

'10 GL550/'04 BMW 545/'99 BMW 323/'98 ML320/'87 VW GTI (race)

Lenny,
The reason I made that statement is, because after working on MBs for thirty years, I have never understood why there are always so many design changes. I have seen parts redesigned once, twice, and even a third time with no noticeable improvement to the part. I just summed it up to an overstaffed engineering department that had to look productive to keep everyone employed. Also if I were King, I would require all designers to use their own product for 6 months before it was marketed. Time and time again I have bought a product and after using it a few times a thought would come to mind. WHAT WERE THEY THINKING? Another pet peave is instruction manuals. I am convinced that some manuals are written by people who have never seen the product they are writing the manual for.

Peter

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Auto Zentral Ltd.

Reminds me of a cartoon I saw.
3 engineers standing around a prototype car, looking into the enginebay.
One says to the others " Let's move the alternator over 3 inches.......because I can still see 1 sparkplug ! ".

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2007 C 230 Sport.

I have been through this crank bolt stuff with Porsche - ~250ft lb area. Fortunately Porsche make a flywheel lock tool which bolts into the bell housing and picks up the ring gear teeth. Makes the whole operation very easy, no danger of damage etc. And they are only $25-30 IIRC. I suggest you check for MB providing such a tool somewhere. I hate talk of sockets engaged and hitting the starter motor!!!
jp

Yeah, I'll admit to this one, we're always tweaking. Changes in material can improve a part's life, while not being noticeable by looking at the part. If I'm replacing a broken part, I'd like the new one to be better whenever possible.
All the higher ups in the organization, not just the designers!
Some manuals are written by people who just learned English, especially the Asian ones...

__________________
Lenny

There are only three sports: bullfighting, motor racing and mountaineering; all the rest are merely games. --Ernest Hemingway

'10 GL550/'04 BMW 545/'99 BMW 323/'98 ML320/'87 VW GTI (race)