OM617 w/ manual 240d flywheel - Page 2 - PeachParts Mercedes-Benz Forum

BirthdayBenz · #16 02-11-2016, 09:40 AM

Lucky me!

Dan Stokes · #17 02-11-2016, 10:43 AM

Quote:

Originally Posted by BirthdayBenz

Not sure what your date of manufacture is but on later production engines (like my 85

) MB changed the crank shaft bore diameter from 35mm to 34mm for which no pilot bearing is made. The first thing I'd do is put a caliper in there and make sure you've got a 35mm bore, otherwise you've got a new problem to solve.

That 34mm pilot bearing was a PITA but I reduced the OD of mine CAREFULLY by hand and it's working well. None of us has been able to find a 34mm OD bearing from any bearing supplier (NSK, Timken, etc.) so we're kind of on our own. If I end up with a crank out of the engine at some point I'll have that bore machined but in the meantime....... If you could find someone with a lathe that's equipped with a grinder (like a crank grinder) they could turn down the OD of a stock bearing, which I might try next time.

Dan

charmalu · #18 02-13-2016, 02:37 AM

I found this picture from an old thread showing the witness mark on the FW.

Here's the witness mark on the flywheel. It must be aligned with a similar mark on the crankshaft.
Attached Thumbnails

Flywheel installed on crank. The witness marks are tough to find...liberal application of Brakleen and vigorous wiping with rags revealed them. On this crank, there's one on the flange and a corresponding one in the relief for the pilot bearing.
Attached Thumbnails

Charlie

MrUkrainian · #19 02-21-2016, 12:28 AM

If I get my manual flywheel balanced to the auto, or neutrally balanced, do I need the clutch also balanced?

charmalu · #20 02-21-2016, 01:20 AM

Quote:

Originally Posted by MrUkrainian

If I get my manual flywheel balanced to the auto, or neutrally balanced, do I need the clutch also balanced?

No.

Charlie

Dan Stokes · #21 02-21-2016, 08:24 AM

To expand on Charlie's answer - clutch assemblies come neutrally balanced so no further balancing is necessary.

Dan

jack.stew48 · #22 02-21-2016, 12:30 PM

just throwing this out there... whats the harm in spending 20 minutes, bolting the manual flywheel to the 0m617 in whatever position you feel is the best, and firing the engine up.

if you dont get any vibrations, then just go for it and save yourself 100$ at a machine shop and all the time and headache involved there.

the only experience i have with this is a good friend of mine who does crazy mercedes diesel swaps (such as an 0m617 turbo in a 450slc, 617 turbo in a 280E, and many more)
anyway he told me he has never had a flywheel nuetral ballanced and ha always is able to get it. he said, if it vibrates, unbolt it and rotate it 180 degrees, if theres still vibration, rotate it 90 degrees, and so on working down in halves of the previous rotation.

aanyway thats just my .02$ and some advice from an old fart whos been doing it a while

leathermang · #23 02-21-2016, 01:52 PM

Jack.Stew48 I agree that checking while the trans is not installed and adjusting the position of the flywheel is the best option if one has it. Hopefully that would take place when the engine mounts were brand new also....
It is a bottom line test which neutralizes ( no pun intended ) many of the potential variables extant... which can be either cumulative or in various self cancelling configurations.
It is akin to the old style balancing of tires by spinning the wheel and finding the needed weights to add with the old Hunter equipment which clamps onto the wheel.... the brake hubs and the rim and the tire can be adding to each other's out of balance.. or partly cancelling each other .... when using that system it was then important to mark the studs so the tire could be remounted at the same orientation if it had to come off.
Trying to match the auto flywheel with a manual flywheel without the inclusion of the front half of the torque converter seems short sighted to me... then sometimes adding the less than perfect situation of using a 240 flywheel on a 300 engine does complicate procedures....
Really smooth real life usage of the car may not be able to be tested since testing without the manual trans ( which may have a vibration damper attached from the factory ) and is also an indicator that the factory knew of some inherent vibration which it tried to suppress by adding that vibration damper to the manual transmission... The fluid coupling ( torque converter ) isolated the rest of the drive train from this inherent vibration.
Someone mentioned ' external balancers'... the one at the front of the engine should be checked when dealing with these issues....
For people putting their own engines together.... it is possible with old fashioned (cheap) self made tools to get pretty much perfect equality between the weights of the pistons,rods, bolts if one has patience....it is static and not dynamic... but it is simple and straight forward.. making a balance beam and comparing them.... using the FSM to take off weight at the appropriate places with a file.
It does not require taking the crank out of the engine...only the pistons and rods... and as such would be perfect to combine with new cylinder sleeves and rings of course...

imryanmoriarty · #24 02-21-2016, 02:07 PM

when I dropped a manual in my w116 300sd I was drunk and didn't mark anything and drove it for like a year until I crashed it and now that engine with the manual flywheel is in my buddy's w123 and is still going strong

if there's no weird drivetrain vibrations I wouldn't worry about it.

e: link to relevant thread: super clean all kustom w116 300sd manual transmission conversion project!!!

leathermang · #25 02-24-2016, 12:34 AM

Drunks can get lucky too.

Rocket99 · #26 06-11-2018, 05:25 PM

Quote:

Originally Posted by Dan Stokes

That 34mm pilot bearing was a PITA but I reduced the OD of mine CAREFULLY by hand and it's working well. None of us has been able to find a 34mm OD bearing from any bearing supplier (NSK, Timken, etc.) so we're kind of on our own. If I end up with a crank out of the engine at some point I'll have that bore machined but in the meantime....... If you could find someone with a lathe that's equipped with a grinder (like a crank grinder) they could turn down the OD of a stock bearing, which I might try next time.

Dan

I encountered to 34mm crankshaft in an automatic trans. vehicle while I was swapping in the manual trans. Yes the pilot bearing is 35mm OD. Those automatic W123s have a different crankshaft part number than the manual trans 300Ds from Europe.

After tearing out hair over it I got the 35mm bearing, mounted it on a 14mm bolt .... the nut snugged up and the outer race spun freely.

Mounted an angle grinder on a bench real stable with a coarse grinding wheel on it. Held the bolt / bearing setup with a vice grip real stable and controlled, and touched the outer race to the grinder surface so it was at 45 degrees to axis of rotation of the outer race. Doing that spun the outer race a mile a minute and also slowly slowly with light touch removed material from the outer race. You can see where the material is being removed, try to keep it uniform across the surface.

Do it slowslow a little at a time, light touch, making it uniform across side to side. checking with a caliper frequently. It worked out OK. Been driving it for years.

Now swapping 5 spd manual into it and will do the same with both a new pilot bearing and also the cap they furnish, also 35mm.

t walgamuth · #27 06-11-2018, 08:21 PM

As usual, Charlie was right. If the fw is balanced to a non neutral crank there should be a witness mark on the fw bolt area and on the crank flange. It is very subtle and hard to spot. I was unable to pick it up but my machinist's eagle eyed son who at that time was in his twenties spotted it.

Most of the 617 fw are neutral but some are not. You won't want it wrong. And the comment about being 10 grams off ....well, that does not seem very much ....1/3oz? maybe that is a lot...?