Alpha 1 Drive - leaky shift shaft bushing

[CableGuy1978]

Hello all,

I have a leaky drive, after discovering oil dripping on the ground after I pulled it from the water this year. I drained it and it was of course milky. I have pressure tested it to isolate the leak. I separated the drive, and tested the upper and lower separately. The upper is good, and holds pressure. The lower is where the leak is. Spraying soapy water around when I had it pressurized, I found it leaking at the shift shaft bushing. Which explains the oil leaking from the small drain hole when it was on the boat.

I am looking for some direction on how to go about repairing this leak. I need to know what parts I should be getting, since I haven't been able to source a kit specifically for that, but rather an entire lower seal kit. I can get each part individually if need be. Also what special tools will I need other than the bushing tool - OEM 91-31107T.

Also, is there a way to flush out the inside of the drive to remove any milky oil that is left in there?

Any tips, info and guidance are always greatly appreciated. Thanks very much!

 

[alldodge]

Re: Alpha 1 Drive - leaky shift shaft bushing

No outdrive expert here but many indicate not to try and flush the drive, it needs to be taken apart, inspected and reassembled. Seen other post to use machine oil and then flush with gear oil, all that still indicates it's better to just disassemble.

 

[ktbarrentine]

Re: Alpha 1 Drive - leaky shift shaft bushing

From the sounds of your drive description it must be an Alpha-1 (non genII), since you cant test the gen II upper by itself. What year/serial number is your drive? That is the only true way to be able to source your parts. I have a 1990 Alpha 1, which uses the following parts for the shift shaft seal/bushing:
26-892361
23-30617A2
25-25439

You find these parts online at various mercruiser parts sources (iboats, for a starter, but there are many others....google the numbers).

As for flushing.... never done it, so will defer to the others who've more experience with that. (my gut tells me if you didnt have that much water in the oil, you could run a volume of gear oil through it once (fill, rotate, drain and see how it looks, then refill after your post-seal replacement pressure testing).

You also need to get (if you dont have one) a "good" OEM service manual, which you can get to by going to the stickies at the top of this forum. That will guide you in replacing the shift shaft bushing (the "right" way).

HTH....
best of luck.
KTB

 

[CableGuy1978]

Re: Alpha 1 Drive - leaky shift shaft bushing

Thanks very much guys for the tips. Specifically, the drive is an "R" - pre alpha, damned if I can find a serial number, but it is complete with lifting eye on top cover of the upper. I do have another drive that needs some work it is to be serviceable again, it has a chewed up bearing in the upper as it had been run with no oil - go figure. It is the alpha 1 "MR". When I got the boat I pulled the broken MR off and put my R on in its place, which works great other than the oil leak.

Anyway, I haven't done much with the drive itself, other than water pump replacement. So I was looking for some ideas on what the books don't tell you. I have an excellent source for parts, so making a shopping list of tools and and parts by number is exactly what I plan to do. I was hoping to avoid having to completely disassemble the drive to clean it out, but if it must be done then I will do that. I was thinking about filling it up with clean oil and running it then changing the oil as many times as needed.

Just want to say thanks again!

 

[84EdH]

Re: Alpha 1 Drive - leaky shift shaft bushing

CableGuy, If your drive has a lifting eye on top of the drive, it is not an R drive but rather an MC-1. serial number can be found on the the upper unit port side, underneath the decal.

 

[achris]

Re: Alpha 1 Drive - leaky shift shaft bushing

CableGuy, If your drive has a lifting eye on top of the drive, it is not an R drive but rather an MC-1. serial number can be found on the the upper unit port side, underneath the decal.

http://forums.iboats.com/non-repair...engine-serial-numbers-630103.html#post4398812

As long as the water hasn't been in there too long (damaged bearing and gear surfaces) then flushing with something light, like kerosene to clean away any traces of water, then a flush though with gear oil, then a refill with the right gear oil should see you ok. If the oil that was in there was Quicksilver High Performance then that should have been enough to protect the surfaces...

Chris.....

 

[CableGuy1978]

Re: Alpha 1 Drive - leaky shift shaft bushing

Thanks for the info everyone. I'm going to do some searching on these units for some proper serial numbers, thanks for the link there Chris..

Also, the only gear lube I use is the high performance stuff from Mercury. I'm not entirely sure on how long water has been in there, though I can say somewhere between June and October... I filled it in June and it has been in the water until just recently. When I noticed the leak, I drained it, pulled it form the boat and pressure tested the whole drive then each half separately.

Thanks again folks for the input.