45 Engine Sprocket Seal Replacment

[Paps]

The 45 engine sprocket seal is a press fit into the bearing race but what is the actual interference fit ? What technics do you folks use for seal replacement installation ? All the nos seals are .005" larger than the standard bearing bore size. That seems mighty tight for a press fit and I am concerned attempting such a press fit may distort the bearing race and or the seal itself. Maybe even damage the case half. Thanks, Paps

[Ohio-Rider]

Paps,
For press fits,The rule of thumb I have always used is, .001 press fit per 1" of diameter. So a three inch diameter would need a .003 press fit and so on. Thats just a good starting point and the metals being joined should be taken into consideration.

To figure an "interferance fit", just cut the "press fit" number in half.

[Paps]

I too utilize the .001" per inch method Steve. Just can help wondering why such a difference in a standard bearing bore and the seal. I think I may have found that answer though. Got to dig out some more nos parts boxes to verify. Paps

[Paps]

OK.....Here is what I found out. The sprocket shaft seal is really an oil slinger. The .005" interference fit is the average fit for the slinger to case race. The slinger presses into the case race from the inside out, after the race has been line lapped or honed. The snap ring in the race stops and seats the slinger into position during pressing of the slinger. You must grease the race before pressing the slinger in to the race. The slinger will not score the finish in the race when protect with the grease, because the slinger material is mild steel and the race is hardened carbon steel. I am told, the later 45 engines actually used a seal instead of the slinger. I'll report more on this when I obtain the data. Paps