harmonic balancer
 

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

Thanks
 

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!

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

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!

Greg,

Glad to hear you got the job done. How did you torque up the new HB?

Peter

You DIYs work too hard, but there must be some consolation in there somewhere. At any rate I'm glad that you were successful.

Peter

We need your words of wisdom for this sort of thing.

Perhaps, bump the starter when things are positioned properly, or ... :)

Was not quite as hard as overhauling an Acura Legend engine :)

It is great that there are people willing to share information.

As far as tightening, I've used my impact wrench, set it at 450 should be okay. I have also used some thread locker on it... (may the next guy howl in pain :) )

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

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.... ;)

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