Main Bearing Retention

[kd]

Does the bearing ever move in, towards the crank? Ive only ever seen them walk out.

Seems the moving is always away from the force.  Flywheel being the force.  Clutch basket being the force.  From what I have seen at least.

Wouldn't the transmission be the force and the clutch basket the receiver of the force?  Even at that, the bearing race moves on the mains shaft toward the transmission when it does move.

Maybe during engine braking but clutch drives transmission. Yes, moves away from the force toward trans.  I have never seen the inner race walk outwards.  Just as flywheel is driving force and bearing race walks away.   

    I was looking in the mirror 

[turboprop]

As luck would have it, one just came in with no bearing retention. Here's a picture after cutting the snap ring grooves.You cannot see attachments on this board.

This looks like the best approach to lock in that bearing (if it is indeed needed). Scott Palmer at Hillside and Larry Larrys Motorcycle Machine have been doing this for awhile. Glad to see others have also figured this out.

[les]

With the double snap rings I bet that first press in of the bearing is touchy to not get it too tight against the snap ring.  That's unless the snap ring groove is positioned so the specialty tool stops it right in the perfect spot.

[hrdtail78]

With the double snap rings I bet that first press in of the bearing is touchy to not get it too tight against the snap ring.  That's unless the snap ring groove is positioned so the specialty tool stops it right in the perfect spot.

George's Garages are.  Touchy is perfect alignment in beginning of press going over the first snap ring groove.

[FXDBI]

With the double snap rings I bet that first press in of the bearing is touchy to not get it too tight against the snap ring.  That's unless the snap ring groove is positioned so the specialty tool stops it right in the perfect spot.

Warm the case freeze the bearing shouldn't need a press.     I like the snap ring idea simple fix.  Bob

[wfolarry]

From my experience the bearing walks from tight rods. Same thing happened with the Evo's in the later years only it was the race pressed on the pinion that would walk out. If your flywheels get out of whack it accelerates the problem. JMO

[Admiral Akbar]

If the crank spreads or twists and the motor makes decent HP, the bearing can walk, even on early SnS cases.  I machined  groove to 0.070 for an 0.62 snap ring like shown in another post. 

You cannot see attachments on this board.

[SP33DY]

With the double snap rings I bet that first press in of the bearing is touchy to not get it too tight against the snap ring.  That's unless the snap ring groove is positioned so the specialty tool stops it right in the perfect spot.

I worked out my machining set-up so that the snap ring sits exactly on the raised part of the press support tool with the machined face of the case sitting on the lower step of the tool. The bearing stops when it is pressed against the snap ring and the tool. It's a very simple operation. The outer snap ring goes on with no problem to finish the job. The inner snap ring probably is not necessary, but it only takes a few minutes to cut the receiver groove, so why not do it?