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DickB
08-14-2011, 08:58 PM
I replaced my alpha with a Stenrdrive Engineering unit last year. It's always been noisier than the original, which I attributed to new gears. Last night it was quite loud; today it definitely sounded like something is wrong. The noise appeared to be coming from the upper. I drained the drive oil and it was pure - no metal particles. I pulled the top cover and inspected the gears and upper bearing, which appeared to be fine.
I pulled the drive and found one of the u-joint grease fittings had come off and was sitting in the bellows. The threads looked beat up. Could that have been hit by the u-joint to cause all the noise? The gimbal bearing seems fine, but I don't have much experience in this area. There is some wobble when I insert the alignment tool and wiggle it. With a metal ruler held flat on the bell housing face, and the end of the ruler up near the alignment tool, I see about 1/32" movement. Is that normal? I adjusted alignment and it took about three full turns of each nut to get the spline marks looking even on a greased tool - is that a lot? Again, I don't have a lot of experience.
The engine ran with no unusual noise with the drive off.
I'm strongly inclined to replace the gimbal bearing as it is probably 12 years old. Engine has about 600 hours.
Looking for other diagnostic or fix suggestions.

Walt. H.
08-14-2011, 09:57 PM
I would consider 1/32" play/movement normal considering you mean moving the alignment shaft up/down & left to right which is actually less movement where the tool passes thru the bearing, but since the gimbal bearing is 12 yr's old I would change it out anyway unless you feel the bearing still turns velvet smooth by hand?

Planetwarmer
08-15-2011, 12:31 AM
I have replaced 2 gimble bearings on an Alpha, and can assure you there was no slop between the alignment tool and gimble bearing. Its easy to pull and replace.

I rented a slide hammer and pulley-puller set from oreilly's. I turned the 3 "arms" on the puller to where the ears were facing outwards. I tied a rubber band around the 3 arms, holding them together at the ends. I inserted the arms into the center of the bearing and unscrewed the arms on the puller until they were opened as far as possible. The rubber band was stretchy, allowing the arms to open. I slid the slide on the hammer maybe a dozen times until the bearing popped out.

I bought a 2 foot long piece of 3" (inside diameter) PVC and the appropriate PVC end cap for something to hammer on.

*****The outside of the bearing will have a hole for grease. Find this hole on the bearing housing and mark the outward facing side with a paint pen.****Then locate the hole on the inside of the gimble where grease is forced into that bearing housing and mark the location to where it will be visible after the bearing has been inserted into place.********There is a thin piece of metal surrounding the bearing housing that can be moved. This may be covering that hole. Slide that piece around to where the hole is open.****

Place the bearing in the gimble, and tap into place. There is no correct side facing out, as long as the grease hole is aligned with the gimble. Make sure the bearing is fully seated. Use the alignment tool to align the bearing with the motor. You simply pull or push on the handle of the alignment tool until the tool will fully insert into the fly-wheel. The bearing "floats" in the bearing housing, so it will pivot.

You might as well change the u-joints. I took mine off and noticed there was some wear, even though I couldn't feel any play. I used a hammer and socket to remove, and a c-clamp and socket to re-install.

Grease everything, re-install everything, fill drive with fresh fluid, go enjoy your new boat.

Walt. H.
08-15-2011, 01:23 PM
It's really nice to be contradicted by a young medical student who has done only one gimbal bearing in his lifetime just months ago with the help of others including this writer who has replaced many gimbal bearings and other drive repairs dating back to the mid 1960's by profession.
Alignment tool dia is not a pressed fit into the bearing and so will have a few thousandth inch clearance but will be much less then the recorded 1/32nd" movement 18 or 20 inches away at the handle end.

The key word to pay attention to as I stated above is "does the bearing turn velvet smooth by hand", and since it was noted to be 12 yr's old with 600 hr's the need to replace could go either way depending how it was maintained and feels today.
Also note: not all alignment tools are machined to the same exact outside diameter specification based on the factory Merc align tool will vary on all the generic less expensive ones found all over the internet................

If in doubt bring it to a professional pay him for his knowledge and sleep well knowing you didn't screw anything else up along the way, just as you shouldn't attempt to perform surgery on yourself or a love one - boat included!

DickB
08-15-2011, 01:30 PM
I did take the boat to a professional shop this morning for a gimbal bearing check and the tech said everything looked and felt good. I was on the phone with SEI a few times and separated upper from lower and spun the shaft by hand. I was told that it should feel smooth but it does not; it feels rough. The tech thinks most likely it is bearings in the upper, so I'm sending the upper to them for warranty coverage.

Thanks for the advice and input. I'll let you know how this turns out.

Dick

Walt. H.
08-15-2011, 02:03 PM
Dick,
That's good to hear it's going to be covered and hope you get a speedy return, also don't forget to refill after you reassemble the two halves..:wrench:
WH

Morgan's Cloud
08-15-2011, 02:29 PM
I would have thought that if both adjustment nuts took three full turns the outdrive might have been a bit sticky to get off ?

DickB
08-15-2011, 03:01 PM
Dick,
That's good to hear it's going to be covered and hope you get a speedy return, also don't forget to refill after you reassemble the two halves..:wrench:
WH
Refill?:wink:
No, it pulled off easily past the fist half inch.

joseph m. hahnl
08-15-2011, 04:35 PM
Refill?:wink:
No, it pulled off easily past the fist half inch.


1/2 -20 thread .050 movement. per turn / 3 turns > .150 or 5/32

1/2 -13 thread .077 movement. per turn/ 3 turns >.231 or 1/4 inches

Not very much at all. I wouldn't worry about that to much, as being abnormal .
there is a running torque check for the upper. While you have it apart have the tech run the check:yes:.

As far as bearings go. A gimbal bearing is a spherical bearing there should be no shake what so ever from the outer to the inner. movement is restricted to swiveling only. If the alignment tool has slop in the ID like was stated then that shake would be acceptable. Bearings are made in Millionths not fractional or thousands. 0.00001 so keep that in mind.

Planetwarmer
08-15-2011, 07:26 PM
It's really nice to be contradicted by a young medical student who has done only one gimbal bearing in his lifetime just months ago with the help of others including this writer who has replaced many gimbal bearings and other drive repairs dating back to the mid 1960's by profession.
Alignment tool dia is not a pressed fit into the bearing and so will have a few thousandth inch clearance but will be much less then the recorded 1/32nd" movement 18 or 20 inches away at the handle end.

The key word to pay attention to as I stated above is "does the bearing turn velvet smooth by hand", and since it was noted to be 12 yr's old with 600 hr's the need to replace could go either way depending how it was maintained and feels today.
Also note: not all alignment tools are machined to the same exact outside diameter specification based on the factory Merc align tool will vary on all the generic less expensive ones found all over the internet................

If in doubt bring it to a professional pay him for his knowledge and sleep well knowing you didn't screw anything else up along the way, just as you shouldn't attempt to perform surgery on yourself or a love one - boat included!


I wasnt contradicting you. I was explaining my personal experience. There was not any noticeable play in the handle. This was not a cheap tool I bought off the internet, it was a tool I borrowed from a local shop. This guy has high-quality stuff.

I am 34, so yes , I am still very youthful.

I have replaced 2 !!! gimble bearings.

Walt. H.
08-15-2011, 08:32 PM
P.W,
It sure sounded that way to me but anyway the point is even the most expensive custom made align tool will have play because the tool's O.D is machined smaller then the inner gimbal bearing race I.D, otherwise you'll be fighting to push it in and pulling it out confusing you whether your adjustment was correct or not and because of that smaller dia you will feel some clearance play at the shafts end.
Next time you have your drive off get an alignment tool and take notice of that, and it's always a good time to check that nothing has moved on you.

I guess it will be soon since you now have to change your shift cable and boot based on what I read in your other post topic.

Ps,
When you once mentioned you're a med student I figured you were still in your 20's, my bad..

Walt. H.
08-15-2011, 08:52 PM
You Tube video showing gimbal alignment tool handling and look close for align-shaft movement.:wink:
http://www.youtube.com/watch?v=x-g6fFYtDLw&feature=related

MOP
08-15-2011, 10:40 PM
Three turns does not seem excessive, I have seen them a lot worse. Three even turns could well have come from the mounts settling.

DickB
08-16-2011, 06:07 PM
Three turns does not seem excessive, I have seen them a lot worse. Three even turns could well have come from the mounts settling.
Thanks for the info.

DickB
08-26-2011, 09:29 PM
Got the drive upper back from SEI today. They replaced the main bearing under warranty. Turning the input shaft on the upper by hand now feels silky smooth, no roughness. Installed the unit and ran it in the hose - no noise, next to no vibration. A short run after splashing and everything was fine. I suspect the bearing was bad from the outset, as the drive always sounded noisier than the old one.

Based on my experience, I can't praise SEI for quality. The lower failed withing a few weeks - it would not shift into reverse. They said the cause was assembly error. And now the upper had a bad bearing. But I can praise the tech support and warranty service. I had to pay for shipping to SEI, but they turned it around in a few days, paid for shipping back, and threw in a gasket set. The tech support was helpful in narrowing down the problem. Now I just hope it holds together for a few years.