??? on maintenance of Alpha One Lower Unit

[Landsend]

I've read on here about maintaining an Alpha 1 lower unit. I've never heard of it, but I'll definitely take your words on the fact you have to remove the lower unit and grease shaft and u-joint.

My question is, I've never done this before, so what does it take to do it? Drain the gear oil, remove the 4 bolts to remove the lower unit (Does the prop have to come off?). Now just grease the shaft? Does the joint have a zerk fitting? When assembling, do I need a new gasket/o-ring/seals?

If anyone can shed some light, it would be much appreciated. I'm very mechanically inclined, so I know I can do it, just want to be prepared.

Thanks!

[Priority1]

Your question about the Alpha 1 lower unit sounds like you mean the whole outdrive assembly. It's a good idea to remove the prop before taking the outdrive off, (less chance of damaging it). This link to aftermarket marine is a good source for information and parts.
http://www.amarket.com/index5.htm
You probably should get a manual that shows in detail what to do. Removing the out drive requires disconnecting the trim cylinders and removing 6 nuts. The manual has many tips and pics that will help you out. I bought one at Overstock.com for $23. Before removing the outdrive assembly MAKE SURE YOUR SHIFT IS IN FORWARD. Just like anything there is a correct procedure. Miss this first important step and trouble city. They make a gasket kit that cost about $5. There is a special spline grease for the spline. A good grade of marine grease is used to grease the U joints, Gimbal Bearing and other lube zerks. Hope this helps. It's not rocket science but it sure helps if you have a manual.

Draining the the gear oil is EZ. Quicksilver sells a kit for $10-$12 that has instructions. You will also need about 1-1/2 qts of Mercruiser gear lube. Don't skimp here with cheap oil. The good stuff can handle a little water infiltration and may save you a ton of money in the long run.

[Priority1]

You may also want to replace your water pump impellor. It is made of rubber and needs periodic replacement. This requires removing the lower unit from the upper. There is also a kit for this and can run $17-$35 depending if you need the top and bottom housing or not. This is very important, and can toast your engine if it is neglected. I think they recomend replacing it every 3 yrs. but this can varry depending on how the boat is used. Sand can tear them up quickly.

[waterfoul]

Landsend... where do you live? I've maintained my outdrives myself for many years... if you're not too far away I'd be willing to give you some first hand, in person pointers.

[Landsend]

Hi Waterfoul,

I live in Dearborn Hts, which is near Detroit. Looks like it may be a bit far, but I do appreciate your offer. I've owned the boat for 9 yrs, rarely used it (Thanks to wife and kids), and had it serviced by a dealer previously. I am a mechanic, but not a marine mechanic. I've read on here about lubing splines and u-joints in the lower unit and am wondering if has ever been done (Nobody has ever told me about this when I've had service done). The boat has extremely low hours, probably just over 100. The boat is still in excellent shape, and I'd like to keep it running sound. As far as the engine goes, I can handle that with ease. I have never touched the lower unit before, and am a little weary of just dropping it down without knowledge of what to do. I think I'll buy a manual to assist me, I'd like to perform the proper maintenance on the unit.

Any recommendations on a manual? I have a 4.3L Merc with the Alpha One Gen II.

One more question for you guys: I want to switch to a 4 blade prop for a better whole shot. I have a 3 blade 14 1/2 x 19 prop that came with it, if I switch to a 4 blade, do I keep the size and pitch or change it?

[Priority1]

Hi Waterfoul,

I live in Dearborn Hts, which is near Detroit. Looks like it may be a bit far, but I do appreciate your offer. I've owned the boat for 9 yrs, rarely used it (Thanks to wife and kids), and had it serviced by a dealer previously. I am a mechanic, but not a marine mechanic. I've read on here about lubing splines and u-joints in the lower unit and am wondering if has ever been done (Nobody has ever told me about this when I've had service done). The boat has extremely low hours, probably just over 100. The boat is still in excellent shape, and I'd like to keep it running sound. As far as the engine goes, I can handle that with ease. I have never touched the lower unit before, and am a little weary of just dropping it down without knowledge of what to do. I think I'll buy a manual to assist me, I'd like to perform the proper maintenance on the unit.

Any recommendations on a manual? I have a 4.3L Merc with the Alpha One Gen II.

One more question for you guys: I want to switch to a 4 blade prop for a better whole shot. I have a 3 blade 14 1/2 x 19 prop that came with it, if I switch to a 4 blade, do I keep the size and pitch or change it?

You keep saying the u joint is in the lower unit. It is part of the upper unit. The U joint connects the UPPER UNIT to a splined shaft that goes through the Gimbal Bearing and into the engine coupler.Get a Seloc manual that covers the year of your Mercruiser.
The manual will also cover the basic engine stuff.
Here is a link that shows a diagram of an Alpha 1 Outdrive.
http://www.boatdesign.net/gallery/showphoto.php/photo/902/size/big/cat//si/22
If you need any more info you are welcome to PM me.:)

[waterfoul]

If you go to a 4 blade you should start one inch in pitch lower. The increased blade area makes up for the change in pitch. Some boats need to go down 2 inches in pitch...

If you are currently running an aluminum prop, step up to a stainless.

[Rootsy]

GEN I or GEN II alpha? GEN II alpha U-joints are non greasable unless they have been replaced... once a year you should remove the sterndrive from the transom assembly, check engine alignment, gimble bearing condition, U-joint condition, bellow condition, shift cable condition and apply Merc spline grease to the splines on the input shaft as well as some 101 or 2-4-C to the shift lever and fork and 2-4-C to the gimble bearing....

Removing an alpha is pretty easy.. getting it back on can be a bit of a hassle for someone who hasn't done it very often...

1) trim all of the way in
2) on gen I remove nuts off one side of the trim ram thru-rods on gen II remove teh C-clips
3) wiggle trim ram off of the rod on the loose side and let hang
4) get a mallet... tap the trim ram thru-rods toward the otehr side while forcing the trim ram against the drive (allows rods to move through so you can get them out of the drive- only need to really do teh rear one btw)
5) shift into forward gear...
6) 5/8 deep well socket and remove the 6 sterndrive to transom assembly nuts and washers...
7) on Alpha GEN II make sure you unhook the speedo tube
8) if the drive does not slide right off and is a bit stubborn, lift it up and let it fall and bounce.. it'll break the seal itself... and you can slide it right out
9) clean all gasket surfaces WELL and discard all o-rings and the cushion ring inside the transom assy - replace with new. no sealer required on the new gasket.. I have always used a bit of grease to hold the water hose o-ring in place.

I leave the prop on because it makes life sooo much easier when reinstalling since you have to turn the drive to get the input shaft splines to align in teh coupler. I also leave enough room between drive and floor to put a good 4 x 4 of wood in there or larger... helps to cushion skeg and balance when reinstalling... and allows you to bounce the drive without hitting the ground.

If you plan to do a lot of your own maintenance on an Alpha get a good manual... the Merc #6 is the factory manual... it is the one i prefer... it covers everything you need to know... the Seloc isn't too bad i reckon...

[POLARBEAR]

Landsend, Check out this site. all the info you need for the job you are about to do.

http://mercstuff.com/

I am sending you a pm.