The easiest and most precise way to install a gimbal bearing

Rivergator

Petty Officer 1st Class
Joined
May 7, 2013
Messages
240
A few days ago I got around to replacing the gimbal bearing in my Alpha One Gen1 drive. I have the alignment shaft and installment tools that came with it, but had a big problem to use it up to now, because it asks me to drill a hole through the shaft and mount the bearing install tool at a very specific, precise location on the shaft. This is a very bad design and idea (IMHO). Unless you are properly equipped with the right tools and skills to do that, it will most likely fail. Either the holes don't line up or you may make a mistake when measuring the precise location on the shaft where to drill the hole for the tool for your particular boat. There's got to be a better and more fool proof way to do this and there is:
Do not mount the bearing install tool on the alignment shaft. Do not use the alignment shaft as a ram rod to seat the bearing. Instead use the alignment shaft as a non-moving rail, as a guide to properly align and seat the bearing. Put the bearing install tool on the shaft followed by the bearing (pic. A) and now you insert the alignment shaft all the way into the coupler. If your drive shaft to coupler alignment is what it should be the alignment shaft will be pretty much centered. Now you need a piece of galvanized pipe 1.5" inside diameter by 18" long with an end cap (pic. B). (Mine is split because I had the 12" piece already. Zoro.com is a good place to get this stuff. Best prices). Now you slide the pipe over the alignment shaft (pic. C) and slap the end of it a couple of times with the palm of your hand to allow the bearing to get started on the bearing seat in the housing. Now the bearing is perfectly lined up and solidly held in place by the coupler in front and the start of bearing itself in the rear. All it took now was 5 or 6 good hits with a 5# sledge hammer and that bearing slipped into place like it was waiting for it. It is good practice to put bearing in the freezer for a few days prior. After that I pulled out the alignment shaft which was fairly easy, telling me that my drive shaft to coupler alignment was good. Btw. the best gimbal bearing removal tool is this one here in my humble opinion. (pic. D)
PROS: No drilling of the alignment shaft, No accidental banging against the end of the coupler because of incorrect positioning of install tool, No messing up of threaded hole for eye bolt at the end of alignment shaft, No stress on bearing or housing because of misalignment when hammering, tool can be used on other boats.
CONS: None except about $25 for the pipe and cap from Zoro
 

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Scott06

Admiral
Joined
Apr 20, 2014
Messages
7,471
A few days ago I got around to replacing the gimbal bearing in my Alpha One Gen1 drive. I have the alignment shaft and installment tools that came with it, but had a big problem to use it up to now, because it asks me to drill a hole through the shaft and mount the bearing install tool at a very specific, precise location on the shaft. This is a very bad design and idea (IMHO). Unless you are properly equipped with the right tools and skills to do that, it will most likely fail. Either the holes don't line up or you may make a mistake when measuring the precise location on the shaft where to drill the hole for the tool for your particular boat. There's got to be a better and more fool proof way to do this and there is:
Do not mount the bearing install tool on the alignment shaft. Do not use the alignment shaft as a ram rod to seat the bearing. Instead use the alignment shaft as a non-moving rail, as a guide to properly align and seat the bearing. Put the bearing install tool on the shaft followed by the bearing (pic. A) and now you insert the alignment shaft all the way into the coupler. If your drive shaft to coupler alignment is what it should be the alignment shaft will be pretty much centered. Now you need a piece of galvanized pipe 1.5" inside diameter by 18" long with an end cap (pic. B). (Mine is split because I had the 12" piece already. Zoro.com is a good place to get this stuff. Best prices). Now you slide the pipe over the alignment shaft (pic. C) and slap the end of it a couple of times with the palm of your hand to allow the bearing to get started on the bearing seat in the housing. Now the bearing is perfectly lined up and solidly held in place by the coupler in front and the start of bearing itself in the rear. All it took now was 5 or 6 good hits with a 5# sledge hammer and that bearing slipped into place like it was waiting for it. It is good practice to put bearing in the freezer for a few days prior. After that I pulled out the alignment shaft which was fairly easy, telling me that my drive shaft to coupler alignment was good. Btw. the best gimbal bearing removal tool is this one here in my humble opinion. (pic. D)
PROS: No drilling of the alignment shaft, No accidental banging against the end of the coupler because of incorrect positioning of install tool, No messing up of threaded hole for eye bolt at the end of alignment shaft, No stress on bearing or housing because of misalignment when hammering, tool can be used on other boats.
CONS: None except about $25 for the pipe and cap from Zoro
I have used a piece of 3” sch40 pvc pipe almost a perfect match for the OD of the bearing and was laying around the garage
 

Sawbones25

Recruit
Joined
Aug 9, 2025
Messages
3
I'm a new used-boat owner and will be installing a bearing and bellows soon. I watched a few videos of people beating on the tool to install a bearing and it definitely left me with some questions about why it is designed like it is. Will definitely give this method a shot. It seems to be more in line with installing pilot bearings and clutch alignment I've done on cars in the past. Thank you!
 

Scott06

Admiral
Joined
Apr 20, 2014
Messages
7,471
I'm a new used-boat owner and will be installing a bearing and bellows soon. I watched a few videos of people beating on the tool to install a bearing and it definitely left me with some questions about why it is designed like it is. Will definitely give this method a shot. It seems to be more in line with installing pilot bearings and clutch alignment I've done on cars in the past. Thank you!
if they are beating on it the bearing is most likely cocked in the transom housing. Going in or out it shouldn't take that much force. The tolerance ring on the outside crushes a bit to hold it but shouldn't need anything than a good sized hammer to drive it in.

Use the OEM bellows for longest life.
 

Leardriver

Petty Officer 1st Class
Joined
Oct 7, 2008
Messages
382
I have the install tool, and don't think much of it. I take a 2x4 hunk of wood about 18 inches long, shave 1/4 or so inch from both sides of one end, until it matches the bearing size, and gently install with a BFH. 2-3 whacks after centering it, and on to the next task.
 

Jmunk

Petty Officer 1st Class
Joined
Jan 31, 2007
Messages
322
I use a large socket with an extension that fits the outter race, a few hammer hits and they go in without much trouble.
 

JFCMoore

Cadet
Joined
Jun 21, 2026
Messages
6
I hoping a few of you folks are still watching this thread - I need your help. 1998 Alpha 1 Gen 2. Torn shift bellows so decided to do a lot of other work while in there, including replacing the gimbal bearing since it came with my kit (now I wish I had not since I believe this is where I'm having problems). NO problem with most of the job with the exception of the oil resevoir nipple breaking off and being impossible to get to in this boat. No sweat, we will simply check the gear oil much more frequently. The real problem is that I simply cannot get the outdrive back on. I have read the manual and looked at a ton of videos and I'm certain I have the setup correct. Forward gear, prop shaft fully counterclockwise, shift linkage line up, everything greased. I even built a small dolly to help position the outdrive. My son and I can get it to the point that we have to turn the prop very slightly so that the splines line up and it goes in another 2 to 3 inches. I'm certain the shift arm is in the right position. I just cannot get the outdrive to go in the last 1/2 inch. Now I'm wondering if I got the new gimbal bearing fully seated. I used the alignment shaft and the special "puck" that is use to push the bearing in. However, I did NOT drill the hole in the tool. Instead I used a piece of 2x4 and a 4 pound hammer to tap the bearing into place. It went in fine and looks great. My alingment is still good. I believe the splines are mated since, as I mentioned earlier, an 1/8 of a counterclock wise turn let us move the drive in - just not the last 1/2 inch.
So, am I correct in thinking the bearing may just not be seated far enough in and is blocking my driveshaft from going fully into place? Is there any measurement out there from the bearing out to the edge of the housing (or somewhere else) to verify it is in far enough. I wish I had measured it before I removed the old one but I failed to do so.
I sure could use some advice on this. I've been fighting this for two days now and it is about to whip me.
 
Last edited:

Jmunk

Petty Officer 1st Class
Joined
Jan 31, 2007
Messages
322
You should be able to put a finger into the bearing and see if you can feel all the way around to see if it’s sitting flush and driven all the way in.
 
Joined
Sep 14, 2024
Messages
65
I just did my gimbal bearing and had the same problem. My alignment was “firm” after. What allowed me to get the drive all the way back in was to wobble the alignment tool hard in all directions, so the alignment was then silky smooth instead of firm. The drive then just slipped right in.

I drilled the hole for the installation driver, and there was no question when the bearing was fully seated. The sound went from a thud while the bearing was moving to a clink when it was fully seated.
 

bspeth

Senior Chief Petty Officer
Joined
Aug 30, 2013
Messages
764
I use the old outer race mounted on the end of a 2x4 which is cut to accept the race. Easy.
 
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