Indian 74 Pinion shim?

[Bills37]

On the Pinion side of the crankcase there is a pinion bearing and thrust washer. beneath this thrust washer is calls for a shim. In the past I have always installed the same amount of shims as it originally came with and have never had a problem. MY question is; how do you determine the correct shim size to begin with. I haven't been able to find any information in any of the literature that I have. Normally I set the end play with the shims on the drive side. Anyone have any thoughts?

[tfburke3]

The rods need to be centered in the cases,so with .015 -.020 total side clearance the wheels should only move half that from center toward the pinion or drive side.
I never needed a shim,some motors may have had one and I didn't notice.If this is not achievable with thrust washers a shim could take up the difference.
I dial indicator on the shaft end is easiest to get end play and adjust accordingly.
Tom

[Bills37]

Screenshot 2026-06-13 063458.png The shim I am referring to is #9 in the picture. As you can see, it is captured behind the pinion race and thrust washer. This makes assembly and disassembly problematic since the wheels need to be installed in the cases to be able to measure crankshaft endplay.



Parts books only call for a quantity of one .006 shim as opposed to "As required" normally called for when referring to shims. This engine had three .006 shims stuffed in there. I was hoping there was some measurements I could take to confirm this before I heat the case and install the race.

[dukekleman]

Bills37,

If I'm understanding your question properly, the short answer would be a Depth Micrometer and a Precision Straight edge without having access to a coordinate indications table.

Measure down from the crankcase centerline mating surface area using the straight edge and depth Micrometer, with the race removed, to the surface the race, shims, etc would seat against when pressed into the crankcase. This will be used when calculating your stack height.
You'll also have to measure your flywheel assembly. Then perform division and subtraction mathematics to determine the stack height of your bearing race, washer and shims that allows the flywheel to be centered in the crankcase.

Hope this helps a little with your question,

Duke Kleman

[Bills37]

Bills37,

If I'm understanding your question properly, the short answer would be a Depth Micrometer and a Precision Straight edge without having access to a coordinate indications table.

Measure down from the crankcase centerline mating surface area using the straight edge and depth Micrometer, with the race removed, to the surface the race, shims, etc would seat against when pressed into the crankcase. This will be used when calculating your stack height.
You'll also have to measure your flywheel assembly. Then perform division and subtraction mathematics to determine the stack height of your bearing race, washer and shims that allows the flywheel to be centered in the crankcase.

Hope this helps a little with your question,

Duke Kleman

Thank you, that answers my question. I was sure it was involving centering the flywheels but I wasn't able to find any information about the process to get there.