I've seen all kinds of threads on making sure that the flywheel is balanced to the crank. However, I'll be running a 616 manual flywheel on a 617 and no marks were visible. Besides, what would 4 cylinder marks MEAN on a 5 cylinder installation?

So:

- Does it matter where a 616 manual flywheel is indexed on a 617?

If all else fails and the whole deal shakes like a leaf I'll bring in an industrial balance guy and have the whole assembly balanced in place. Just wondering if I can stop worrying.

Dan

i hope you marked your fw position. I'd take the five cylinder fw and have it checked, and yes, if it is not neutrally balanced the fw will need to be matched to it and reinstalled in the same place. If its neutral it can go on in any position.

When the fw is not neutral it is because the crank needs it to be weighted to offset the imbalance of the crank.

__________________
[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 don't think it makes a difference. It could be wrong or it could be right. I gambled on my set up Dan and it was just like yours. I think it usually will be correct. No marks, no reference to where or how it was mounted, so I just put it on, (did use new bolts) and have been very happy with it. I do get a little vib at between 45/55 mph under full throttle. That is a good time to go back to 3rd gear for a minute.

__________________
Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

How can it be installed "in the same place" if it's going on a different engine?

__________________
When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

in the same place as the flywheel that came off that engine, which may have an off center balance.

The process ends up being mark the flywheel and crank, take the new flywheel and get it match balanced with the one you marked, install the new flyhwheel in the same position as the old one.

the majority of the time it seems people find the original flywheel was a neutral balance, but every now and then theres a 617 with a biased balance.

__________________
This post brought to you by Carl's Jr.

Most of mine have been neutral...prolly at least 5. My eighty four two eighty e was not though. If you are unlucky and its not neutral and you put it on it will shake your teeth out.

I do know the factory service manual says to have all of them match balanced.

__________________
[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 had to have it done on a 85 617. It was needing a match balance. 1 out of 2 for me so far. I did not check the first. I hope I'm done with that for a while.

__________________

Chris
84 280sl
82 300d euro

JB3 found no reference marks on his, (last I checked), and yet it wasn't neutrally balanced... I would strongly recommend that if Dan has both FWs on hand, he should check the balance. Shouldn't take too terribly long, and it'll certainly be less painful than pulling the thing apart if it isn't neutrally balanced.

__________________
"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

I had my flywheel neutrally balanced for my auto to manual swap on a 617.951 wagon. I have had no issues with excess vibration.

After I did my swap, I found out that Mercedes inline engines do no use bob-weights to balance the crankshaft. They are balanced to the flywheel. American V8's use bob-weights, and the flywheel is irrelevant to the equation.

I operate a Sunnen balancing machine at a performance engine shop. The operation manual noted that the flywheel is used in balancing Mercedes cranks.

__________________
1982 300TDT
1991 190D
2022 Metris

Thanks for all your thoughtful input. You guys is da best!

I think I'll go with Plan A, given that the engine is installed and in the process of being hooked up. So I'll hope everything is neutrally balanced (is that neutered?) and if not I'll get it balanced in place. I guess we'll see.

If I knew these engines when I started this project I would have had the flywheels matched but I can honestly say that I didn't know no better (as we say in the Southland).

Dan

As long as there wasn't a witness mark on the CRANK your good since theres no mark on the FW also.

__________________


1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

I looked carefully and didn't see a crank mark. Fingers crossed!

I did a little on-line exploration today and there IS an industrial balancing company here in our area (actually in Leland, just across the Cape Fear River from Wilmington). My job would be pretty small for them but hopefully I can lure them over here if necessary. And hopefully it won't be necessary!

We quite often used industrial balancing folks in my job and they can do magic! This is a resource that we all should keep in mind if we get unexplained shakes in our vehicles.

Dan

I don't know how it could be balanced on the engine.

The witness marks on my two eighty were nearly invisible so look very very carefully after cleaning the mating surfaces carefully.

__________________
[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.

Did that (looked carefully, that is).

As far as balancing in place - we did that all the time. They set up a 3 axis accelerometer and read the point and amount of imbalance. The engine is running (in the case of an installed engine the vehicle will be up on a hoist) and they mark a reference so they know where the relative imbalance is located. Then metal is either removed from the heavy spot (for example, by drilling the dampner) or Mallory metal is added until all is back to smooth. The driveshaft will, of course, be removed which is easy on a Benz as the fluid won't all pour out. They generally add the driveshaft and check the assembly with it in place following the balance of the main component.

This is done all the time in industrial situations such as pumps, pulp mills, etc. and is a well developed science. We used it on dyno setups if the system proved to be shakey. Following the balance the whole deal is then "externally balanced" so you need to be careful to mark everything at this point to keep all the components in balanced relationship to each other.

Dan