Rear crankshaft seal

[wgcjim20]

I don't know if it's significant that 76.2mm = 3"

[Carledo]

Is it possible, I ask myself, that there are 2 ways of measuring, fitted and unfitted?

Steve

[Mad Mart]

When I measured the seal ID, I measured the smallest diameter which is the flexible portion, hence why I said approx.. When ordering a seal you need to know the diameter of the shaft it's fitting over. As Steve alluded to, the engineers have taken the flexible bit into account so if you order a 3" (76.2mm.) ID seal, you know it's going to fit a 3" shaft.

[Adder57]

Yes I agree, and the size given for the crankshaft was 76mm so is that not the size needed. Don't understand why 76.2mm was quoted. Is there anybody who has used a double lip seal, and do they know the size etc. It would be useful for members to have this information for future reference as you don't want to be doing this Job twice.

[Mad Mart]

FFS. I measured a used crank which was probably warn. I used a vernier to check the measurement (which isn't the most accurate tool). I may have even rounded to the nearest millimetre. The crank is going to be 3 inches, as it is imperial. 3 inches is 76.2mm.

[Adder57]

Don't get mad mart. That's what I wanted to know does the seal fit the shaft. I will buy one from simply bearings and when fitted, let members know how it performs. Thanks for your time. Adder

[Carledo]

I did wonder why all the fuss over 0.2mm! That's like 8 THOUSANDTHS of an inch! With the production tolerances the Sprint engine was built to, that's phenomenal accuracy!

Steve

[Mad Mart]

Don't get mad mart. That's what I wanted to know does the seal fit the shaft. I will buy one from simply bearings and when fitted, let members know how it performs. Thanks for your time. Adder

Apologies. Must have gotten out of the wrong side of the bed.