Reseal L/U - How hard is it?

[Grant Brown]

1989 Merc 70 3 cyl.

My L/U is leaking oil and getting water in the case. I had it pressure tested on the bench and the shift shaft seal started leaking oil right away and I could hear air leaking out near the prop shaft. I bought the full seal kit from the dealer for $130 CDN and I was planning on taking it to a local guy I know who quoted 3 hours at $65/hour.
Unfortunately my wife found the bill for the parts so now I'm thinking of saving a few bucks and doing it all myself. I was told that this motor does not require any special tools as it's the design with two bolts holding the prop shaft carrier (right name?) to the back of the L/U.
I have rebuilt some small engines before, done rings and valves etc. but not much marine stuff other than the impeller. I also have no experience with gearcases or transmissions. I have access to a factory shop manual.

Grant

 

[Laddies]

Re: Reseal L/U - How hard is it?

With a manual it's not a difficult job.

 

[Scaaty]

Re: Reseal L/U - How hard is it?

Yep..get a manual and it will be pretty easy. Just MAKE SURE any shims (and they can be hard to see if only a couple thousandths think) get put back in the right place​

 

[finlay]

Re: Reseal L/U - How hard is it?

ull be right mait if u are handy with tools ull be able to replace some seals. there all easy to replace and get to the only problems u may incounter is a seased carrier and seased carrier bolts. use a little heat when removeing carrier will help alot.
also if u r doing the drive shaft seal u will have to look at water pump gaskets and also make sure u replace your oil bung washes.

 

[Grant Brown]

Re: Reseal L/U - How hard is it?

After much thought and lots of time staring at the parts diagram I decided to let the mechanic do it. I felt very intimidated by all the shims and gears etc. It took him less than 2 hours and he charged me only $100 cash. Much better than the 3hrs @ $65 he quoted and way better than the 4hrs @ $95 I was quoted by the local merc dealer. I should have asked him if I could watch, but I have way too much to do these days.
I'm going to run the boat this week and then take it to him to get the carbs cleaned. It bogs like crazy for 1/2 hour or so until I shut it off awhile. Then when I restart, it runs like a champ for the rest of the day. I'm thinking that the carbs are gunked up and the fresh gas acts like a solvent and loosens stuff up. I put it away the year before last without draining the float bowls so I guess this is payback for a dumb mistake. Could be worse though.

Grant