1976 9.8hp 110 crankshaft seals..upper and lower seal the same part?

[Bassman86]

I know there are separate part numbers on the diagrams for these parts but a reliable mercury site sells the same part for upper and lower seal so does anyone know if that's accurate? and the seal that is in the end of the crankshaft what is it and is it necessary it looks like it will be destroyed getting it off so I can change the Lower seal but don't see that as a part anywhere or see a need for it? thanks

 

[emckelvy]

Oil Seal P/N 66301 is used on both upper and lower ends of the crankshaft. The lower seal slides onto the end of the crankshaft and is sandwiched in grooves machined in both the block and crankcase cover. The upper seal is pressed into the upper bearing cap.

To answer your other question, the seals keep air in and water out. If the seals are leaking, the engine cannot develop crankcase compression and either will not run or run poorly.

HTH........ed

 

[Bassman86]

the other seal im referring to is the part that is outside the crankcase or block, it looks more like a cap on the lower end of the crankshaft, it's not the lower oil seal

 

[emckelvy]

the other seal im referring to is the part that is outside the crankcase or block, it looks more like a cap on the lower end of the crankshaft, it's not the lower oil seal

Oh, that one! It's what keeps water out of the crankshaft and driveshaft, preventing them from rotting away. There should be enough "give" in the new seal to allow it to pass over the driveshaft seal area.

If there are any sharp or raised edges, be sure to put a wrap of electrical tape around the sharp edge & oil or grease it so that the new seal will slide over that area without damage.

Note that if the new seal won't pass over the end, you'd have to remove (likely destructively) the stainless driveshaft seal assy, then tap a new one on the end once you've installed the new seal. If you're unable to carefully drive the seal assy off the end of the crank, you could score it gently with a Dremel tool & grinder disc, until you're able to split the sleeve and remove it.

HTH.............ed

 

[Bassman86]

OK thanks. I think I undestand it didn't seem like it wanted to come off I tested it a little I'd hate to pass a new oil seal over it and loosen up through new seal or stretch it out.. u seem very knowledgeable if you can will check out my other motor posts and see if you can offer some insight? thanks