Hi everyone;
I wonder if it is cost effective to swap a lefty for a Timken? I guess so if going over 125 ft/lbs or high revving, but what about a mild 110 or even a 120
ST?

 

I would not do it.

 

Tnx;
The engine would be taken down anyway (crank welding), but wouldn't want to Timken
just for the sake of it...

 

if your going to tear it down to install a SE "lefty" bearing,i would definitely do the Timken conversion.the SE "lefty" bearing isnt any better than the stock bearing.if the HD lower ends where a one piece crank,the 2 roller bearings would be OK,but being a 3 piece unit,the timkens give the lower end much more stability

 

You left that out of your OP. If tearing down anyway, replace the roller with the Timken.

 

Didn't know the lefty isn't really better than stock; will definitely do the conversion!
The engine (120R) has to be be taken down anyway...

 

A Timken locks the wheels solidly in that left case.
Scott

 

Is it tricky to install to get the proper bearing preload?

 

Not really but a service manual is highly recommended. A "dummy" shaft to set preload is pretty handy and will save time.

 

I make up dummy shafts if anyones interested.a must for setting up any timken motor from pans to TC's