Broken harmonic balancer

[Casey]

On petrol M-B engines a hub puller is required to get the harmonic balancer off, I assume diesels are the same.

On my engine the harmonic balancer is heated to 100C in an oven then slipped on.

Thought I saw some where here the balancer is drilled round it's edge to balance the crank/engine and can't be swapped and a new balancer should be drilled to match the old.

koan

Ouch - I guess I'll need to figure out where to get a hub puller - never used one before - do I just get any one or is there something more specific to look for?

Hope it doesn't need drilled because I've got no idea how to do that.  This is the part:



The two small metal bits on the inside ring are broken off on mine.

[koan]

Ouch - I guess I'll need to figure out where to get a hub puller - never used one before - do I just get any one or is there something more specific to look for?

Hope it doesn't need drilled because I've got no idea how to do that.

I used a $20 hub puller set from a car parts place.

The balancer is drilled round the edge, yours will be drilled to match your engine, new balancers are not drilled.

The two small metal bits on the inside ring are broken off on mine.

I don't think they broken off but missing, aren't they two short, round dowels that key the hub to the crank?

koan

[calvin streeting]

Both my w123 and w116, had holes drilled in edge. Bet it has to be balanced with crank shaft.

[s class]

The balancer is drilled round the edge, yours will be drilled to match your engine, new balancers are not drilled.

Correct.  You can't simply mix and match these items. 

The two small metal bits on the inside ring are broken off on mine.

I don't think they broken off but missing, aren't they two short, round dowels that key the hub to the crank?

Yes, they are separate dowels.  Refitting the damper is tricky, because you need to heat it, and slip it on EXACLTY right because otherwise you will never get the dowels in. 

[koan]

Yes, they are separate dowels.  Refitting the damper is tricky, because you need to heat it, and slip it on EXACLTY right because otherwise you will never get the dowels in.

I did it on the second attempt, so it can't be that hard! Didn't get it fully on the but bolt pulled it into place.

koan

[s class]

Yeah OK, I guess its not tha-a-a-a-t difficult.  I just wanted to make the O.P. aware that at least some measure of care and forethought is needed to avoid a lot of misery. 

[koan]

I was lucky, was expecting a lot more drama with it.

koan

[Casey]

I don't think they broken off but missing, aren't they two short, round dowels that key the hub to the crank?

They are broken off.  I found them both inside the pulley, well chunks of them anyways.  The other chunks are still attached to the big piece.

[Casey]

The balancer is drilled round the edge, yours will be drilled to match your engine, new balancers are not drilled.

Correct.  You can't simply mix and match these items. 

What does this drilling look like, and how specific is it to a given engine?  If I pull a balancer from an engine at a junk yard, any good odds it will fit on my engine?  What is the purpose of this drilling?  If I purchase a new balancer, how do I drill it?

[Casey]

This is pretty much the exact same thing that I'm facing:

http://www.youtube.com/watch?v=msTcGmK6AOA

[1980sdga]

I have read accounts of this happening with early OM617's.   I'm always paranoid about this.  Now I'm more paranoid...

What motor is in the 300D? Some engines have the balancer balanced at the factory as a set with the crankshaft.

Good job catching it before something worse happened!

[koan]

They are broken off.  I found them both inside the pulley, well chunks of them anyways.  The other chunks are still attached to the big piece.

Have a look at job 03-340 for your engine in the library, gives cross section and exploded view of relevant parts.

koan

[koan]

This is pretty much the exact same thing that I'm facing:

Is the crank snout damaged on yours as well?

What does this drilling look like, and how specific is it to a given engine?  If I pull a balancer from an engine at a junk yard, any good odds it will fit on my engine?  What is the purpose of this drilling?  If I purchase a new balancer, how do I drill it?

Seems there's an extra piece on the diesels not on petrol engines. There's an harmonic balancer and a balancing disk. It's the balancing disk that is unique to your engine and a new disk needs to be drilled to match the old. The book says to do it on some sort of balancing rig but I've read somewhere it's sufficient just to drill matching holes in the new one.

See job 03-344.

If the crank end is damaged though I think you might have bigger problems.

Incidentally, the MB book says to mark the pieces, I think the guy in the video has got it wrong.

koan

[calvin streeting]

idea could you put the old balancer on a wheel balance machine recored the off balance (as it wont be connected to the crank). then so the same with the new one and drill to match to unbalance of the old one. that way they would be the same as each other.

just an idea..

[jbrasile]

Casey,

The video illustrates your problem perfectly, my only concern is that I am not sure if the balancer and crank aren't balanced as a unit as other members mentioned, that would really complicate things.

You would need to check with a shop which has some experience with these engines,  why not give the guys at MercedesSource a call?

Tks ,

Joe