Are balancers interchangeable for a OM617 in a 300D

[paulster]

I am in the process of replacing the engine in an 85 300D with what I believe is a good used engine from an 82. The crankshaft balancer on the 82 was pulled for some reason, without orientation being marked, and it has two sheared pulley bolts and one of the locating pins is buggered up (broken and stuck in the balancer; other one is missing).

The balancer on the 85 is in fine shape.

Question: can I just swap the 85 balancer onto the 82 engine, orient to TDC on the compression stroke, and move on? Is there a different way to orient? Are these balancers interchangeable between model years on a 617 engine, or do I need to have it matched (or RnR the 82 balancer...)?

I ran across this thread, which references balancers as "matched" and it gave me pause... but I can't find any definitive information.

https://www.peachparts.com/shopforum/diesel-discussion/334484-1980-w116-300sd-om617-front-crank-seal-replacement.html

Anyone know?

[Frank Reiner]

Originally Posted by paulster

I ran across this thread, which references balancers as "matched" and it gave me pause... but I can't find any definitive information.

https://www.peachparts.com/shopforum/diesel-discussion/334484-1980-w116-300sd-om617-front-crank-seal-replacement.html

Anyone know?

The crankshaft front hub/harmonic damper (aka, "balancer") is included with the crankshaft and flywheel in the process of balancing the crankshaft. Hence, those three pieces constitute a unique set. If a replacement front hub is to be installed, its balance must be matched to that of the hub being replaced.

[paulster]

Ok, so I should be able to take the original and a replacement damper/balancer to a machine shop and have them matched without needing to pull the crankshaft and flywheel. Good.

Now a related question... as mentioned, the pins on the original balancer are missing and the locating holes are a bit wallered out. I have no way of knowing if it spun on the crank at some point, but it's obviously suspect. I assume an out-of-balance crankshaft could damage the seals over time, but if they're okay should I worry about anything internal? Bearings? Play?

[engatwork]

If they are not leaking I'd leave em be.

You may have to contact more than one machine shop to find one that can balance it as needed. In Macon, Ga there is a company that is called B&D Services. I suspect they have machinery to balance a balancer.

[Frank Reiner]

Originally Posted by paulster

Ok, so I should be able to take the original and a replacement damper/balancer to a machine shop and have them matched without needing to pull the crankshaft and flywheel. Good.

The piece to be balance matched is the hub that is pressed onto the crankshaft. The rubber bonded harmonic damper is neutral. My original phrasing was confusing.

Now a related question... as mentioned, the pins on the original balancer are missing and the locating holes are a bit wallered out. I have no way of knowing if it spun on the crank at some point, but it's obviously suspect. I assume an out-of-balance crankshaft could damage the seals over time, but if they're okay should I worry about anything internal? Bearings? Play?

The bearings are likely OK, however, since the engine is out they can be inspected easily at this time.