Mystery shim on drive shaft

[ozforce]

Hello all. I was directed here by Andy Nasser from Crowley Marine as they could not provide me an answer.
Ref:1996 Force Outboard 50 - H050412SD [ELPT].
Although this is a Force motor it has all Mercury parts.
When I disassembled the lower unit and the drive shaft, I discovered a 0.060" ring on the drive shaft below the bearing See photo. Can anyone please explain this part and why it is not listed in the parts diagram referenced below.
If I was to simply re-assemble the unit I would not be asking, but I am replacing the drive shaft because of wear at the seals. I suspect it might have something to do with pinion gear clearances?

GEAR HOUSING ASSEMBLY (DRIVESHAFT) - 1996 Outboard 50 H050412SD [ELPT] | Crowley Marine

View parts diagrams and shop online for GEAR HOUSING ASSEMBLY (DRIVESHAFT) parts, 1996 Outboard 50 H050412SD [ELPT]. Offering discount prices on OEM parts for over 50 years. FAST $4.95 shipping available.

www.crowleymarine.com

 

[jhande]

Looks like a snap ring usually found in some bearing seals.

 

[ozforce]

Looks like a snap ring usually found in some bearing seals.

That might be true if it was on the other side of the bearing where the seals are.

 

[QBhoy]

Might be just the picture quality...but is that serious heat markings on the shaft near the left bearing ?

 

[ozforce]

Might be just the picture quality...but is that serious heat markings on the shaft near the left bearing ?

Sure is. also near the pinion gear on the other end. I have not picked up the new shaft yet, so I have nothing to compare it with.

 

[QBhoy]

Sure is. also near the pinion gear on the other end. I have not picked up the new shaft yet, so I have nothing to compare it with.

Weird one eh. Does it even fit over either ends to have come from somewhere else ? Doesn’t look like it. Looks alien to me.

 

[ozforce]

Weird one eh. Does it even fit over either ends to have come from somewhere else ? Doesn’t look like it. Looks alien to me.

It has the same OD as the bearing, so logic says it sits under the bearing to lift the shaft up and supply more clearance for the gears to mesh.
My question is do I really need it as it is not on any parts list. was the housing machined in correctly or is there variation on the bearing thickness?

 

[Faztbullet]

The tempering marks are normal from factory,,the shim was factory added most likely due to housing tolerance and preload specs not met. You will need to reinstall it

 

[ozforce]

The tempering marks are normal from factory,,the shim was factory added most likely due to housing tolerance and preload specs not met. You will need to reinstall it

Thank you; just as I thought. I wanted to clarify before re assembly.