1 reply [Last post]
Micha's picture
Joined: 10/12/2007
Posts: 390

Say the crankshaft is out from the engine, and I checked for endplay on the conrods and in my opinion they are normal and minor, is there any reason to fear the crank and rods bearings are shot?
I have never ever treated the crank assembly and of course have no idea what previous owner did or did not to it.
Will it be wise to send it all to the workshop to take everything apart, overhaul it and balance it? For being on the safe side?
Or shell I follow the known US saying – " If it ain't broke, don't fix it"?


Michael Steinmann
R51/3 1952
Engine Nr. 529466

dardaris2725's picture
VBMWMO #2725
Central NY
Joined: 10/27/2006
Posts: 44
R51/3 crank

I think as long as the crankshaft is out you owe it to yourself to check it out thoroughly. I hope you have a decent workshop manual to guide you. The endplay on the rods is a critical point. "normal and minor" may seem ok but the specification for new is .000 - .005mm, and a good serviceable crank has .010 - .015mm radial clearance between rod and crankpin. You really need a dial gauge to measure and if you can "feel" it, it's too much.
As for side clearance between rod and crankpin, .07 - .10mm is normal.

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