Can't get motor to align with new gimbal bearing RIGHT and LEFT DIRECTION !

jimmoe

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Oct 25, 2011
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36
I'm stumped and frustrated ! U-joint bellows went bad on my '89 17' fiberglass Lazer so checked gimbal bearing and it was spinning rough and ordered a new one. Also ordered an alignment tool but that box came empty with a hole in the end. Rather than wait for the replacement tool, I pulled the bearing without checking the existing alignment, before installing the new bearing, made sure the tool (91-805475A1) fit nicely inside the engine shaft, installed the bearing and the tool marked 3/16" off to the left (from the behind the boat) and a tad high of the engine shaft, adjusted height and that centered the mark up and down but still way off to the left or in other words when I pull the tool out without turning it, there are spline and half circle marks in the grease on the right side of the end of the tool. I removed the front engine mount (to boat) bolts and moved the mount in quarter inch increments as much as 1" to the right with no change, then did the same to the left with no improvement. I checked the transom plates for movement and tightness to the hull and it checked OK, the transom is solid and shows no sign of the plates having movement from damage, etc.. The engine to transom plate bolts and spring pockets were tight allowing no movement right or left. I actually pulled the new bearing and reinstalled it cocked a little bit, right side ahead of the left...checked it when half way installed and the tool fit further into the shaft by about an inch leaving no grease marks on the end and would spin easily, pushed the bearing all the way in tight on the right side but not quite on the left and the tool would not insert that inch and still marks an 1/8" off to the left.
The motor is an '89? MCM 3.0 LTR *130*HP per the spark arrestor/carb cover ( 140 HP / 3.0ltr R / Mr / Alpha per the serial# 0C621830 search) Transom serial# 0C787685 and drive serial# 0C800668 are all listed on the carb cover, the serial numbers match those on the transom and drive. The motor has always had some serious shake at idle, don't know but suspect misalignment as the cause.
I'm lost as what to do next and hope some one has some answers or ideas.....please !
 

GA_Boater

Honorary Moderator Emeritus
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May 24, 2011
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49,038
You need to watch these two videos by achris. The front mount not be should not be moved left or right, only up or down.



 

jimmoe

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Oct 25, 2011
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36
Thanks for the quick reply, GA !....During the football games no less !
I had watched many videos, and read a lot of threads, some one said the mounts would need to be reset to get right and left movement....after I found that did not work, I put them all back where they were and re-tightened. Since this was my first gimbal bearing replacement, I first watched several videos and read may threads, but none of them addressed the fact or showed that there should be that much swivel in the gimbal portion of the bearing. The new bearing I received did not swivel so I thought that was the way it should be :facepalm:. Chris' videos showed that movement clearly and that it should swivel easily. As soon as the game ended.... (Go Pack !).... I pulled it and put it in a vise, it took all my weight on it to get it to swivel and had to grease it and work it to get it free enough to turn when installed. :happy: TaDa ! :happy: It is in and aligned !..... Wondering if I got a bad or cheap bearing because it was so hard to swivel ?
Thanks again for your help :D
 

GA_Boater

Honorary Moderator Emeritus
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May 24, 2011
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It's amazing how much a gimbal bearing gimbals. :smile: Chris's video really shows it.

The bearing are pretty tight and no telling how long yours sat on a shelf with the grease setting up. Give it a good shot of fresh grease.
 

jimmoe

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Oct 25, 2011
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36
Yeah, this was definitely tight with no evidence of grease when it finally did swivel. I greased it by hand in the vise and thru the zerk when installed..... the grease came out the back, a lot of grease, I assume thru those slots on either side.
I wonder, is it supposed to be greased until it fills the void between the back of the bearing and the seal ?
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
All Merc genuine gimbal bearings have been the sealed variety for at least 10 years now. If you are grasing your new one, it's aftermarket, and that might will explain why it was so tight...

If you used a slide hammer to pull it back out, then pull it out again, throw it in the rubbish bin and buy a new one... You can only get them out by hammering on the inner race, and that will destroy them...
 

jimmoe

Seaman Apprentice
Joined
Oct 25, 2011
Messages
36
The new bearing did have the hole to receive grease from the zerk, also the inner race did not protrude outside the plain of the outer race on the aft side but was slightly inside it..... obviously after market.....I bought this one because it was the only reasonably priced one I could find that spelled out compatible with the R / MR Alpha Gen 1.... I did use a slam hammer to remove it and should have known better since I did see your video about not hammering on the inner race while installing, not smart enough to apply that to removing it :facepalm:.
Unfortunately, I had it all back together before I read your reply, it definitely ran smoother than before.... I will order a new bearing and try to do it right this time. Do you think it will hold up to a half dozen hours of planned outings before I get a chance to do that ?
Thanks for your help....I will definitely search yours and GA's posts before attempting any more repairs.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
It shouldn't be a problem for a few trips. You'll hear it when it goes! Gimbal bearing has been the same since about 1969 to current... Even if it says Alpha One Gen II or Bravo, it'll fit...

Chris...
 
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