The running fit of the bearing (radial play) between the races and roller is the only thing affected by oversized roller. Example... if your using new Jim’s outer race, and new Andrews main drive gear. The ID of the outer race should measure 1.8802”, and the OD of the Inner race on the MDG should be 1.6290”. 1.8802”-1.6290”=0.2512”. You take this number, subtract your desired running fit (I try to stay as close to 0.0010” as possible.). So 0.2512”-0.0010”=0.2502” you divide this number in half to get the size roller that will give you your desired running fit. 0.2502”/2=0.1251”. So in order to achieve 0.0010” running fit you would need bearings 0.1251”, Standard bearings are 0.1250”, and the next oversized is 0.1254”. So you would go with 0.1250” (standard size) bearings. To check yourself double the bearing size 0.1250”x2=0.2500”, take the 0.2512” you achieved earlier and subtract that number 0.2512”-0.2500”=0.0012”. This would be your running fit using standard bearings with new races.
End play is set up with a shim. Eastern Parts sells these in thicknesses ranging from 0.040”-0.080” in 0.005” increments I believe. They have a common set of 4 different sizes P/N: 35131-SET (for reference). This shim (washer) goes on the main drive gear before any assembly! I suggest using your existing one for measuring purposes. (Do not use more than one shim). Place shim around main drive gear and insert MDG into outer race (which you should already have installed in the transmission case). Then install your 44 rollers in place (use the ones that you will be running to achieve correct running fit, as this can slightly change the end play). Once rollers are in place, install the seal spacer and sprocket. (No need for seals at this point, it all will have to come apart to change the shim). Tighten the left handed nut and set up a dial indicator on the outer face of the sprocket. While slightly turning the sprocket back and fourth, pull out and push in on it. Read your measurement. If it’s within tolerance specifications, simply remove sprocket and install cork ring and oil seal (do not forget seal spacer keeper. This keeps the seal spacer spinning in the seal.). Then re-assemble sprocket. If it is out of spec. Chose how much endplay you’d like from the wide spec. given in the service manual, and the number from you dial indicator, say 0.016”. So if you have a 0.060” shim in place when taking this measurement and you’re shooting for 0.005” endplay simply subtract 0.005” from the 0.016”. 0.016”-0.005”=0.011” then add that number to the thickness of your shim. 0.060”+0.011”=0.071” that is the shim thickness you would need to achieve desired endplay. The closest shim to that being 0.070” would give you a endplay of 0.006”. To change the shim just take the main drive gear back out, interchange the shim with the desired one, then re-assemble.
Sounds like a lot but it’s pretty simply, double check your math and everything will fit just right!
The More You know!