The balancer on my 350SDL is in perfect condition except for the inside hub which was worn out when the key split in half (The entire balancer will "wobble" on the shaft.)

Is it possible to buy just the hub?

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1982 300GD Carmine Red (DB3535) Cabriolet Parting Out
1990 300SEL Smoke Silver (Parting out)
1991 350SDL Blackberry Metallic (481)

"The thing is Bob, its not that I'm lazy...its that I just don't care."

If it will wobble on the shaft then you can bet the crankshaft has some damage.

just put a used harmonic ballancer on there and keep driving. I don't know the cost of new, but the rad comes out real easy, and you should be able to get the old one off with a gear puller. If you don't have one, you can "rent" them from local auto parts stores. Do use a new woodruff key and put locktite on the bolt.

I agree with Forced induction. Its not likely you can just do that and have it last for long.

Unfortunately a buggered crank nose usually requires a new crank.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

I unfortunately have to 3rd that decision, from what I know and past experience around machinery. You might get lucky, but you need to go over that crank snout with a micrometer and verify it isn't worn down or else you'll be back to square one in short order. If you caught it right off you might be ok, any extensive time with it that way and you're likely in for a crank. As far as the balancer, if you're talking about separating it at the rubber grommet part, I've never seen one sold that way since it is a pressed/molded together affair. You might pick one up inexpensively from a rebuilder such as Damper Dudes. Get a plan of attack, assess the crank, if needed find a good one at the wrecker, maybe from a car that was in a side/rear wreck, means the car was running when it got there. (avoid frontal wrecks as this usually kills the oil cooler and possibly starves the engine until stunned owner shuts down).
Buy new bearing shells, you never ever want to transfer a used shell between engines since they wear differently. Grab a good balancer while you're there. You can always go for new or rebuilt parts too if you prefer $$.

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Chris
64 190D R.I.P.
80 240D W/617 engine -for sale
82 240D -for sale

The front of the crankshaft is fine. There is no pitting or anything. Its the inside of the hub that is worn.

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1982 300GD Carmine Red (DB3535) Cabriolet Parting Out
1990 300SEL Smoke Silver (Parting out)
1991 350SDL Blackberry Metallic (481)

"The thing is Bob, its not that I'm lazy...its that I just don't care."

I hope you are exactly correct.

Good luck.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

So do I, and to that end when I get home today i'm going to measure the hub and compare it to a new balancer. Then the crankshaft, just in case.

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1982 300GD Carmine Red (DB3535) Cabriolet Parting Out
1990 300SEL Smoke Silver (Parting out)
1991 350SDL Blackberry Metallic (481)

"The thing is Bob, its not that I'm lazy...its that I just don't care."

Fulcrum,

My other current car affinity is early M1 Mazda Miatas. The 1990 version had what Mazda called the "sport crank," otherwise known as the "short nose" crank. Your described problem happens all the time with these early engines due to dealer techs who do not know about or notice the miniscule difference between the ends of the woodruff key when changing the timing belt. Put in the wrong way; it quickly creates the problem you describe. Google "miata short nose crank repair" and you'll find detailed pictorials and descriptions of how the folks over there deal with it. I have done this to my autocross Miata that has a BRP supercharger and it's a stump puller. I drive it like I stole it and haven't had any trouble in well over 80K miles. Mine's not the short nose but I bought it with the problem and someone had botched even the painfully obvious orientation of the key on a 1.8l.

Might be worth a look.

Sam

I've read and re-read your post. The crank is much harder than the balancer. The balancer is two pieces that have a rubber interface molded in during manufacture. If the balancer wobbles, remove it. Measure the crank dia with a dial gauge. You'll have to put the bolt back in and turn it by hand. also measure the id of the pulley. My thoughts are, the pulley is shot. Buy another and be on your way.

Ahh, but be careful on this, true that cranks are hardened...in certain places such as journal surfaces to certain depths. The entire crank is not and cannot be hardened completely, it would shatter quickly if that were the case since cranks actually do flex back and forth at the rod journals with each combustion cycle from the sudden explosive forces, and hardened steel is very brittle, unable to absorb that. As to whether or not the snout is hardened, I don't know for sure, but have my doubts since it is not a heavy load wear surface as a bearing journal would be.

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Chris
64 190D R.I.P.
80 240D W/617 engine -for sale
82 240D -for sale

very sorry, but I believe that is completely wrong. Nitride hardening occurs on the entire surface of an item. It is heated evenly and completely in a type of gas bath. There is no reasonable means of nitride hardening specific locations on larger items.

http://www.longwear-nitriding.co.uk/htm/benefit.htm

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I believe he means that the crank isn't hardened throughout (not just the "skin")

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

no. it appears he is assuming that the surface for mounting the balancer is not as hard as the balancer and therefor the crank has been compromised.

the debate is wether the material of the balancer can ruin the surface of the crank

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Paging Kestas:

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'84 300SD sold
124.128