TOPIC: water in lower unit - gaskets?

When I winterized this fall, I found some water in my lower unit oil. Motor is a 1964 500. So this spring I was going to replace some gaskets. At the oldmerc.com website I see:

WATER PUMP BASE TO GEAR HOUSING GASKET

TOP/BOTTOM CRANKSHAFT SEAL, DRIVE SHAFT SEAL & PROP SHAFT SEAL

WATER PUMP HOUSING SEAL

DRIVE/PROP SHAFT SEAL & WATER PUMP COVER SEAL

I have a boat mechanic buddy that just said buy the parts and he will come over and show me how to do it. Any suggestions ? Lord knows when the last time these were replaced if ever. Do I change all these?

I also see they (oldmerc.com) sell a gasket set. These all look more like the motor gaskets and not the lower unit ones. Should I get these and work my way through all the motors gaskets?

Any recommendations or suggestions are welcome and appreciated.

Joe

Hey Joe,
I too had water in my lower. Figured some main was leaking. Turned out to simply be the o-rings on the fill/drain plugs. Check those first.

As for replacing gaskets, I personally only replace ones that are clearly leaking, OR any questionable gasket I come across when performing other work. "Don't pick at the scab"

I've had great luck finding gaskets and seals (ex:the upper and lower water pump seals) at boats.net

Peter is correct. You first need to pressure test the unit & find out where it's leaking. Might be as simple as the plug gaskets. If you need to reseal it it's a fairly complicated process. But all of the seals are available from various sources. Personally I'd get a a lower unit seal From NAPA or your local Merc dealer.

If ( big word )this 50 HP lower unit is original it may have a carbon steel driveshaft.--They often rust right where the seals ride on them. I install thinwall stainless sleeves on them when needed.----Seals do harden and wear out and after all these years will need to be replaced and it is not all that hard or involved to do this.-Complete seal kit is the way to go.

The Professor is right on this, as a possibility. Best to yank it and have it pressure tested, as tell ya in a second whats what. And on the thin wall sleeves, called "Speedi Sleeves " Great for restoring worn trailer bearing seals too.

www.skf.com/group/products/seals/industrial-seals/power-transmission-seals/wear-sleeves/skf-speedi-sleeve/index.html

dont forget the shift shaft seal.