Pre Alpha Gimbal Bearing

[bbook83]

I have a 1974 140 Mercruiser, outdrive serial #3587926. I purchased a transom seal kit that included a gimbal bearing assembly, Sierra # 18-2100, which says it replaces OEM # 30-60794A2. The Mercury diagram for my serial number shows # 30-879194A02, which was "superseded from" 30-60794A2. Will I be ok using the Sierra # 18-2100? I note that there is a Sierra # 18-21001 which apparently replaces OEM # 30-879194A02. I'm not sure what the differences are and why one part number was superseded.

 

[alldodge]

The new design for both Merc and Serra removes the grease capability (no hole). They are sealed bearings

http://www.amazon.com/Mercury-Quicksilver-Parts-Gimbal-Bearing-Sealed-Nohole/dp/B004QJJRJ6

Two good things with sealed bearings is water cannot get into them as easy and they don't need greasing. The bad is you cannot grease them

 

[Bt Doctur]

18-2100 is the greasable one, 18-21001 is the sealed one

 

[bbook83]

I didn't know there was a "no-hole" sealed assembly. The 18-2100 I bought definitely has the hole and is a visual match to the aft end of the one still in the gimbal housing, which is "greaseable", so I should be good to go. Thanks for the helpful info.

Now, if I follow the manual, I will install the new bearing with the notches forward, although the old bearing has the notches aft. Iboats archives say the notches forward installation was to eliminate the ability to twist the bearing out without removing the housing. Lots of interesting history here.

 

[thumpar]

The notches are supposed to be in like you stated.

 

[Fishermark]

The notches are supposed to be in like you stated.

That's true, but the truth is it can go either way.

 

[thumpar]

I know it will work either way but notches in the way you are "supposed" to do it.

 

[alesk565]

I recently changed gimbal bearing, and to me it helped alot that the old one had the notches facing backwards. I welded some axial strings along the housing and it came out really easy.

Still curious why it should be mounted according to the new standard..

 

[alldodge]

It doesn't matter, either way works

 

[Bt Doctur]

Back in the early days the bearing was installed with the slots facing aft so you could remove just the bearing and replace just the bearing.
IF THE BEARING DID NOT SPIN IN THE HOUSING.
If the bearing locked up and spun in the housing , the complete assembly had to be changed.
Most did not know the bearing has to be installed in a certain way to allow it to get the grease.. There is a small hole in the bearing that must be lined up with the grease groove in the tolerance ring. Installed backwards the bearing gets no grease and will fail .
The manual was updated to have you replace it as an assembly . As far as I know the bearing by itself is not available .