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When should you replace the Gimbal Bearing?

G

gonflyn

New member
Hey, I have seen a lot of a instructions and videos on how to replace a Gimbal Bearing on a Mercruiser Sterndrive. My question is, "When and why (or Both) should the Gimbal Bearing be replaced? How will you know if you need to, what are the symptoms of a bad Gimbal bearing? Or is it a preventative maintenance item to do at fixed intervals?
 
The main symptom is when running in gear in the water, you turn you steering almost all the way to either direction like making a turn and you will hear/feel a grumbling/growling sound/feeling.

Replace ONLY as needed. Mine in my 1987 boat as far as I know is original and I have owned the boat since 1995

Now if you service your outdrive every year ( remove it to grease ujoints and do a general check) (if your ujoints are serviceable) then you simply stick two fingers through the bearing and feel it. If it is not smooth then replace it.

The service part is based on year of the boat. newer models (I forget the year it changed but in the 90's) went to non serviceable ujoints. No greasing required the need to remove the drive is somewhat not done any more.

Me I remove the drive no matter what. I check and grease the gimbal bearing if it is grease-able as the newer ones are no longer grease-able.
I manually grease the input shaft and replace all gaskets and o-rings and do a general inspection. It also will show after sitting all winter if the upper carrier bearing decided to leak and leave a lot of gear oil in the bellows.......
 
If your gimbal bearing is serviceable (meaning that there is a grease port that directs new grease into the bearing), be sure to do this dynamically.
In other words, add grease with the engine operating at idle speed.
Doing this dynamically helps ensures a more complete exchange of old for new!

And NO...... you will likely not see this being suggested in an OEM service or workshop manual.


.
 
Hey, Thanks for all the info. After taking my Upper unit off.....due to the gears being toasted, It at least looks like the Gimbal bearing and everything else looks to be ok. Other than the fact when it was put back together, the guy used RTV Silicone instead of a gasket?

I do have one additional question, there are two holes in the Bell housing, that were filled with the RTV? One is just above the right top mounting stud, and the other lower left below the Water line? What are these for? The lower one looks like it's not a through hole...can't tell with the top yet, got to pull out all the Silicone?
 
my 87 alpha one was a little stuck coming off.No water leaks .Did noticed gimball looked a little dry on grease.I did grease it every season before docking..I did not hear any noise from gimball during use.I did notice some irreguarilty turning the gimball ,not looseit was suppose to have been replace 4 yrs ago
Does the bearing need replacement?
thanks
john
 
john1947 said:
my 87 alpha one was a little stuck coming off.No water leaks .Did noticed gimball looked a little dry on grease.I did grease it every season before docking..I did not hear any noise from gimball during use.I did notice some irreguarilty turning the gimball ,not looseit was suppose to have been replace 4 yrs ago
Does the bearing need replacement?
thanks
john
Click to expand...
Hard to tell from here, by irregularity’s what do you mean rough? I usually grease mine while idling on the muffs to get grease through out the bearing. Would think no it doesn’t need replacement but you want to turn it while greasing to make sure fresh grease gets in
 
Dieter said:
Hard to tell from here, by irregularity’s what do you mean rough? I usually grease mine while idling on the muffs to get grease through out the bearing. Would think no it doesn’t need replacement but you want to turn it while greasing to make sure fresh grease gets in
Click to expand...
I think it needs a through greeting first check later
Thanks
 
Shaking hands with a mechanical object will not answer your question.....

Spell check!!

""Thorough Greasing"""
 
kghost said:
Shaking hands with a mechanical object will not answer your question.....

Spell check!!

""Thorough Greasing"""
Click to expand...
I always talk nicely to my bearing before install....

Seriously to OP removal all the old grease you can, if solid it may be sign of water intrusion...

Spin the bearing while you grease it to expel all the old grease whip off any excess in there as that can insulate the bearing.

Be happy you still have a greasable one... I just replaced the non greasible u joints on my gen two drive two of the legs of each cross the grease was dark and had ridges worn in them. Lubed for life.... a short life only 300 or so hrs on it never got water in bellows...
 
kghost said:
The main symptom is when running in gear in the water, you turn you steering almost all the way to either direction like making a turn and you will hear/feel a grumbling/growling sound/feeling.

Replace ONLY as needed. Mine in my 1987 boat as far as I know is original and I have owned the boat since 1995

Now if you service your outdrive every year ( remove it to grease ujoints and do a general check) (if your ujoints are serviceable) then you simply stick two fingers through the bearing and feel it. If it is not smooth then replace it.

The service part is based on year of the boat. newer models (I forget the year it changed but in the 90's) went to non serviceable ujoints. No greasing required the need to remove the drive is somewhat not done any more.

Me I remove the drive no matter what. I check and grease the gimbal bearing if it is grease-able as the newer ones are no longer grease-able.
I manually grease the input shaft and replace all gaskets and o-rings and do a general inspection. It also will show after sitting all winter if the upper carrier bearing decided to leak and leave a lot of gear oil in the bellows.......
Click to expand...
 
I’m in the process of bellows replacement on an alpha 1 and I’m also replacing the gimbal bearing. I didn’t mark on the installation tool where the bearing should be seated. Is there another way to know where to seat the gimbal bearing?
 
You seat it all the way in. If your using a hammer (3 lb hand sledge hammer) and a bearing driver, you will hear the tone change when seated.

Then its best to use an alignment bar/tool to align bearing with coupler. The outer race of the bearing itself is spherical and the bearing can be rotated plus up/down-lefr/right but in a rotational manner.

The aluminum outer rung with the krinkle band is a carrier for the bearing

What tools are you using to install?
 
kghost said:
The main symptom is when running in gear in the water, you turn you steering almost all the way to either direction like making a turn and you will hear/feel a grumbling/growling sound/feeling.

Replace ONLY as needed. Mine in my 1987 boat as far as I know is original and I have owned the boat since 1995

Now if you service your outdrive every year ( remove it to grease ujoints and do a general check) (if your ujoints are serviceable) then you simply stick two fingers through the bearing and feel it. If it is not smooth then replace it.

The service part is based on year of the boat. newer models (I forget the year it changed but in the 90's) went to non serviceable ujoints. No greasing required the need to remove the drive is somewhat not done any more.

Me I remove the drive no matter what. I check and grease the gimbal bearing if it is grease-able as the newer ones are no longer grease-able.
I manually grease the input shaft and replace all gaskets and o-rings and do a general inspection. It also will show after sitting all winter if the upper carrier bearing decided to leak and leave a lot of gear oil in the bellows.......
Click to expand...
I have a problem with servicers not removing the drive at least occasionally- they can't know if someone else worked on it and used the greasable U-joints or gimbal bearing and some don't install the plug when they install the newer bearing, which results in problems if someone decides to lube it.

If a shop is extremely busy, I can understand (to a small degree) not wanting to remove the outdrive but if the person writing the work order does their job, they should ask the boat owner if certain service has been performed, or look in the customer's file if they always do the service.

IMO, the only outdrives that are difficult to remove are Bravo or other dual-prop versions because of the weight and a servicer should have an outdrive jack if they do this frequently. Alpha drives aren't terribly heavy or difficult to reinstall, so it's far better to remove it and know, rather than leave it and guess about the condition.
 
cjskerkis said:
I’m in the process of bellows replacement on an alpha 1 and I’m also replacing the gimbal bearing. I didn’t mark on the installation tool where the bearing should be seated. Is there another way to know where to seat the gimbal bearing?
Click to expand...
Make sure to note the red dot for where the grease port is or would have been on the bearing (if you use the new style bearing). If your boat had the greasable bearing, install the plug (it's just a stainless set screw, really).

You'll hear AND feel the difference when it reaches the end- don't try to kill it- it'll go.
 
jimn said:
Make sure to note the red dot for where the grease port is or would have been on the bearing (if you use the new style bearing). If your boat had the greasable bearing, install the plug (it's just a stainless set screw, really).

You'll hear AND feel the difference when it reaches the end- don't try to kill it- it'll go.
Click to expand...

FYI

They stopped selling greaseable Gimbals bearings years ago. So if he is replacing it its not greasable.
Also he doesnt say Gen 1 or 2....

If I thought that was what he was asking was about the grease hole aligment, I would have mentioned the alignment of hole in the carrier.....

He says "Seat" the bearing which indicates to me he thinks there is a certain depth the bearing is to be installed to.

If he was referring to the grease hole alignment then he need to start over and use the correct description.
 
I always check alignment before removing old bearing & adjust if necessary because installing the new one will cause it to rotate in the ring & if alignment is out, you end up chasing your tail.
Much easier to use tool to leverage bearing back straight & verify alignment a 2nd time than to do everything at once.
 
kghost said:
FYI

They stopped selling greaseable Gimbals bearings years ago. So if he is replacing it its not greasable.
Also he doesnt say Gen 1 or 2....

If I thought that was what he was asking was about the grease hole aligment, I would have mentioned the alignment of hole in the carrier.....

He says "Seat" the bearing which indicates to me he thinks there is a certain depth the bearing is to be installed to.

If he was referring to the grease hole alignment then he need to start over and use the correct description.
Click to expand...
The greasable ones are still available.

I just wanted to mention it in case he had that type.

I think more people need to find out where bearings and other parts are seated before removal. Just my opinion.
 
The greasable ones are available I bought one for my bin of spare parts. Mine was replaced 20 years ago and has gotten greased every year with pulling the drive to check for water in the bellows, smoothness of the gimble bearing, the ujoints and input shaft seal. U joints are original as far as I know and have not needed replacement since I’ve owned it (2002).
I have a drive jack & an alignment bar 2 necessary tools if you want to maintain your own sterndrive.
 
FYI

There are three threads in this post.
The original is from 2017

The last one is from 2025.
This is the one that the recent posts are for.

Greaseable bearings or not
The only ones being sold NEW by Merceuiser are sealed NON serviceable.

Discussing greaseable really should not be discissed Unless the poster of the 2025 post has a gen 1 and wants to replace with what was originally installed.

He has not respinded with what gen drive he has and has made no indication of what bearing he has purchased.

so if anyone wants to purchase a new OEM Gimbal bearing, the only choice is non servicable unless it is NOS or aftermarket.

(Note:-The actual bearing used, Not including the carrier, is a standard bearing commonly used in applications like drive shaft support bearing, which at one time could be purchased from any source like auto/truck parts store for about $25.00 Mercury put an end to that for the most part as they want control to control the price.)
The very early mercruiser gimbal bearing replacement was done with only the actual bearing. No carrier assembly.

You spun the spherical bearing race to align with the slot in "outer race" and simply pulled it out with your fingers.
Even though it could be greased by hand, there was No grease fitting which was added later when the use of the aluminum carrier was incorporated into the design.

The current bearing itself is still the same design with the exception it is non greaseable/sealed. It can be spun and removed/replaced. If you can find and purchase just the bearing.
 
Sierra sells what I think are Link-Belt bearings, not sure of the quality, but that's for owners of older sterndrives.
 
louc said:
Sierra sells what I think are Link-Belt bearings, not sure of the quality, but that's for owners of older sterndrives.
Click to expand...

Its been a long time since I bought just the bearing but that may be the brand name. I have serviced a few of those old ones a very long time ago but I have always bought from local marine store as I have two very close to me. Also up until the last 5 or so years, the merc part used currently was not that expensive aa compared to today.

I looked up the link rod from the intake manifold bimetal chimney to carb choke linkage. $50.00...
For a 2 or so inch long, 3/16" diameter steel rod with two 90* bends on the ends and a minor Z in the middle!!!

I think merc has become full of itself with parts pricing..
 
They are all bad like that, Merc, Volvo and what's left of OMC...
example:
OMC wanted like $300 for the same Carter marine mechanical fuel pump you can buy from Summit Racing or Jegs for $70-$80.
Or $300-$400 for a starter that you can buy from ARCO for about $175-$185
Or an alternator, about the same thing.
I feel sorry for people with late model Mercruiser 4.5s, the parts for them are sky high expensive, in the realm of what outboard parts cost, with no aftermarket alternatives as of yet. Nice engines but will get very expensive to keep going as they age. Especially if you ever have to replace the cat converter exhaust.
If I were up for learning new skills, I think I'd rather have a direct drive inboard, probably the least expensive marine propulsion system you can find.
 
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