1974 280C Harmonic Balancer bolt Torque spec.

[grubby65]

Replacing the water pump on my 280C. Looks like I'm going to have to pull the Harmonic Balancer. Does anyone know what the torque spec is for the bolt?
Thanks

[Frank Reiner]

No need to remove the crankshaft front hub; remove six socket head (aka "Allen") screws that hold the pulleys and dampener (Balancer).

[grubby65]

Originally Posted by Frank Reiner

No need to remove the crankshaft front hub; remove six socket head (aka "Allen") screws that hold the pulleys and dampener (Balancer).

Seriously? Wow that is at least some good news. I think I understand why Mercedes-Benz mechanics get paid so much, it really isn't about their expertise, but it allows them funds for psychiatric help due to mental anguish. It just shouldn't be this difficult. I think someone torqued the bolts that hold the fan to the water pump hub with a 3' cheater.

[kraakevik]

I often replace the 10mm-head fasteners for the fan with cap screws with 12- or 13mm heads if they'll fit--makes it much easier to install and tighten them up.

In removing the harmonic balancer allen-head bolts make sure the recesses are meticulously clean so you don't strip the heads. If they're reasonably substantial bolts 30 lb-ft or so in torque should do the trick--good luck



Tim Kraakevik
kraakevik@voyager.net

[Dr. Benz]

Those allen head screws are often rusty and very tight. I often use heat on them a couple of times to help break the rust bond that forms. Once you chew up the head of the screw your are screwed.

[grubby65]

Well I got everything completed. New water pump, belts, some of the hoses, & thermostat. Man what a project! On the Harmonic Balancer bolts I had to resort to cutting up an allen wrench and welding the 1" pieces into the bolt head so I could get them out. Hope I never have to do this again.