Replacing rear seals on MC-1 (pre-alpha) drive?

Uraijit

Banned
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Feb 5, 2008
Messages
884
I noticed a bit of gear oil in the prop section of my drive when putting it back on, after removal and a water pump impeller replacement.

I'm thinking it may just be some that dripped on there while things were torn apart, but I'm not certain. I'm going to keep an eye on things, and maybe drain some gear oil and check for water after a few hours on the water.

It may be nothing, but it may be something.

If it turns out to be something, and I have leaking seals back there, is this something that's easily replaced, or am I going to end up tearing down the whole lower unit? Before anybody jumps all over me about getting a manual, I have one, but it details a complete tear-down and reassembly of the drive. It's kind of hard to pick out what would be involved in replacing whatever seal would be leaking, if there is in fact a leak.

I just want to get an idea of what's involved. I gotta get myself psyched up for it, if it's is going to be another 3-week-long event if I have to replace a seal, or is it something that can be done in an hour or two, maybe even with the drive still on the boat?

The previous owner claimed to have just had the entire outdrive rebuilt before it was passed off to me, so the gears and all should be in good shape. I'm not looking to do a complete rebuild, just replace a seal (if in fact it turns out it needs it). Doable?
 

kikroks

Cadet
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Apr 7, 2008
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23
Re: Replacing rear seals on MC-1 (pre-alpha) drive?

first of all to replace a seal your gunna need special tools just to get to it if its in the lower portion you can leave the stern drive on the boat and just remove the lower ,but what u can do without taking any thing apart is a preasure check remove the gear oil and screw a preasure guage into the vent screw and pump air into the oil filler scew do not put over 10lbs psi and check for leaks you can try soapy water and a spray bottle and look for bubbles around seals
 

Uraijit

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Feb 5, 2008
Messages
884
Re: Replacing rear seals on MC-1 (pre-alpha) drive?

Thanks for the response. What sort of price range am I looking at for buying tools?

How many hours labor would one expect to pay a shop to do it?

Would I be better off just paying $695 for a new SEI lower unit, than paying someone to rebuild this drive (again).
 

fishrdan

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Jan 25, 2008
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6,989
Re: Replacing rear seals on MC-1 (pre-alpha) drive?

Ijit,

I replaced my prop shaft and carrier seals in a few hours with the drive still on the boat. The hardest part was making a spanner wrench for the the carrier nut, but after the carrier nut was off and carrier pulled out it was pretty straight foward. Drive out/in prop shaft seals, change carrier seal and put everything back together. Easy cheesy if you have some mechanical skills
 

Fishermark

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Oct 19, 2003
Messages
5,617
Re: Replacing rear seals on MC-1 (pre-alpha) drive?

The previous owner claimed to have just had the entire outdrive rebuilt before it was passed off to me, so the gears and all should be in good shape. I'm not looking to do a complete rebuild, just replace a seal (if in fact it turns out it needs it). Doable?

If it was rebuilt then the lower seals should not be leaking.

If it wasn't rebuilt... then replacing the lower seal may be a challenge, depending upon what is leaking. Given the age of the unit, and where the outdrive has been - salt water vs fresh - it may be near impossible to pull the lower prop bearing retainer. I know on the last pre alpha unit I had I ended up letting a marine mechanic take a shot at it... no luck. It was STUCK! Just a heads up before you go and spend a lot of money on something that may not be fixed practically or easily.
 

Uraijit

Banned
Joined
Feb 5, 2008
Messages
884
Re: Replacing rear seals on MC-1 (pre-alpha) drive?

Thanks for the info guys. I'm thinking that IF the drive was rebuilt, they may have damaged the seals, which would explain the leaking. But I'm not even sure it IS even leaking. I took her out for a couple of hours today, so tomorrow, I'll check the drain plug, and look for any water. As I said before, it may just be spilled oil from when I tore her apart.

I'll keep an eye on it either way.
 
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