azinn

See

http://www.mercedesshop.com/shopforu....php3?t=119790

///AMG55

Thats great but I still have no idea what the hell that things purpose is! please fill me in.

azinn

See -
http://www.mercedesshop.com/shopforu...d.php3?t=63512

GDawgC220

I'm assuming since it's a recall and if your car is out of warranty and affected, they'll take care of this free of charge?

nice find btw

Darkmann

The harmonic balancer is the pulley on the front of the crankshaft - you know what the c'shaft is, don't you? It's usually the lowest pulley, way down there when looking at the engine from the top, where all the other pulleys attach to - I say usually 'cause I haven't even taken the time to look at the ML's pulleys yet!!! It basically runs all the other belts. As the c'shaft rotates the other belts follow. Now here's the problem: The c'shaft speed depends on a few things, but mostly how heavy your right foot is. On the other side, the belts have some lag in them due to age and tension variabilities, the A/C running on and off and other accessories coming on and off. So, even if magically you could run the c'shaft at a constant rotational speed, the demands on the belts change constantly. In order to make sure that these differences between c'shaft speed and the rest of the pulleys don't drive one another completely crazy (read destruction), engineers figure out that if you could have a flexible interface between the c'shaft and the rest of the drive pulleys, that'll do the trick - the pulleys can do whatever while the c'shaft does it thing according to the demands of your impatient right foot!!!

Guess what they did? The invented the harmonic balancer. It's made up of three pieces - a steel inner part, which bolts to the crankshaft, a rubber sleeve around that which dampens crankshaft vibrations and the outer steel part, which has grooves for the belt.

The rubber middle piece is the workhorse which is wrinkled back and forth to match the oscillatory demands of the c'shaft and the drive pulleys - that's where the harmonic thing comes from. Now, in a highly demanding (and hot) engine like the ML's V6, what happens is that the rubber sleeve is extremely tasked (due to poor cheap design), wears out and pushes the outer part of the pulley away from the engine. Problem is that as soon as this starts to happen, though there's still the vertical pull force of the belts (a bit reduced though), an additional horizontal force has been added because of the extension of the rubber sleeve towards the front of the engine. That force gets larger and larger as the rubber sleeve extends further and further. It pulls the belt off of the other accessories, including the water pump, and in most cases, this is what ultimately shreds it. In general, to inspect for this, take a peek at your pulleys (engine OFF please!!!!!!!) and check to see how the pulleys are aligned. is there one that looks way off???

A bit long but you asked for it and I thought it'd be nice to detail it as much as I know about it. Auto engineers, chime in.

Darkmann

///AMG55, click here here for an even better and more technical explanation of the HBalancer.

pcy

I just called my local dealer to see if the harmonic balancer recall campaign applies to my vehicle ('98 ML320); after giving my VIN, they said YES. I just made an appointment for next week.

THANK YOU guys for the info.

ML God

we are changing a ton of those now...get in and get it changed asap

ML320CHROME20s

Mines failed on me back in Nov. 03. Think i can get a reimbursment for this? The parts , labor , and towing all cost me $700.

jtse

For some reason, after the harmonic balancer change that I had recently changed, the Car seems to rev higher than usual. Like the position where I accellerate on the gas petal now is reving higher and the whole car seems to be just a tad bit higher torque, or soemthing of that sort. Is that normal, have you guys experienced any of these things?

beemaze

Just had the harmonic balancer changed today. I notice no difference whatsoever.

We also had the power steering hose replaced for the 3rd time. I can't believe this continues to be a problem. This time it dumped most of the PS fluid all over the garage and driveway. We couldn't drive it, so I had it towed. You should have seen all the fluid it dumped on the service driveway. It was so bad, they decided to move it out of site from the rest of the customers

GregW / Oregon

Did you read the first post? That's what it says. According to the Service Campaign, if you paid out of pocket for a repair on a covered vehicle, and have proper documentation, it is reimburable.

Billiken

According to my dealer, the part numbers (on my 2000 ML320) were not part of the service campaign.