250 sl flywheel

[rmmchl]

Car was vibrating about 55 miles per hour. Dropped the transmission to inspect torque converter. It's ok, but the flywheel need replaced. I was told it has to be balanced with the crankshaft. Is this true. That means engine diasassembly. Any thoughts?

[A Dalton]

No

 Engines with 7 main bearings were not balanced w/flywheel...

[ja17]

Hello rmmchl,

Yes A Dalton is correct in that these seven main engines have balanced componants. The exception is the early 250S,SE (sedan engines) which had seven main bearings and "counterbalanced" flywheels. As long as yours is a 250SL engine you will be fine.

A "counterbalanced flywheel has an obvious mass which counters the throws on its crankshaft.

You are safe to change just the flywheel unless your car has this early 250 series sedan engine.

Joe Alexander
Blacklick, Ohio

[Ricardo]

Hmmm...as one with an SE engine in my 250sl, I'm wondering if I have an "early" one....any idea of the engine numbers involved Joe?
Richard

[ja17]

Hello Ricardo,
Not likely that you have a counterbalanced engine. A low number of the very early 250 series sedans had them. I'll try to find the engine number reference for you. You could also check by shinning a flashlight on the back of the front engine vibration dampner from below. If it is a counterbalanced engine, the  it will have one mass on one portion of the counterbalance. If it is not counterbalanced there will be three equal masses.

Joe Alexander
Blacklick, Ohio