MC-1 (aka Pre-Alpha) Gimbal Ring Replacement

[RWVaught]

I have a 1975 MC-1 233. I have to replace the gimbal ring. I have the lower gimbal ring shaft out, and the long allen screw at the to of the gimbal ring is removed.

The gimbal ring is loose, but I can't get it clear of the upper shaft (as I pull out on the lower part of the ring). Do I have to remove the gimbal housing, in order to get to the steering lever off of the upper gimbal shaft?

Are there any tricks, or shortcuts I can take here?

RW

 

[dubs283]

Are there any tricks, or shortcuts I can take here?

You need to remove the nut on top of the steering shaft and loosen the tiller arm to drop the shaft out of the gimbal housing.

You're gonna have a tough time finding replacement parts too. You may be able to upgrade to a later style alpha transom assy. The only hangup would be the inner transom plate. It needs to properly connect to the flywheel housing on the engine. Being a Ford it may not be an easy task

 

[flashback]

2 ways I know of, pull the engine for access to the tiller arm or cutting an access hole in the gimbal housing.

 

[RWVaught]

2 ways I know of, pull the engine for access to the tiller arm or cutting an access hole in the gimbal housing.

Regarding the latter; I assume this has been done successfully? What size hole do you recommend, and how do you keep it from leaking after the fix?
RW

 

[BillWilliams]

I know there are kits sold for Alphas and Bravos to cut access holes in the gimbal housing. I'm not sure for pre-alphas.

The kit I've used is 22-88847A1. This requires drilling two holes on the side of the housing where the tiller arm is. I know there are other kits that involve cutting the aft portion of the same area.

 

[flashback]

Regarding the latter; I assume this has been done successfully? What size hole do you recommend, and how do you keep it from leaking after the fix?
RW

I've not done it but a few here have. You need the kit for dimensions and assorted hardware. I'm not knowledgeable enough to say if it works on the MC..

 

[kenny nunez]

I have removed that nut without drilling but it is a PITA. With a punch and a suitable hammer it can be worked loose depending of the construction of the boat. There is a 1/4” pipe plug screwed into the bottom of the shaft that has to be removed with an Allen wrench also.
The seals should be reusable if they are not torn.
If you can get the drill and plug kit that will be a big help.
If you are doing this because the splines are worn in the top of the ring then with a reciprocal saw just cut the ring at the 10 & 2 O’clock positions which is the thinnest area. If you are able to loosen the top nut have a helper hold the nut while you rotate the remains of the ring back and forth to remove the nut.

 

[RWVaught]

Thank you, that is all very helpful.

RW

 

[1960 Starflite]

Thank you, that is all very helpful.

RW

Please keep us updated. I may have to go that route too. My 1979 Century 140 hp is getting sloppy.

 

[ROY WILLIAMS]

Thank you, that is all very helpful.

RW

the service manual of the Mercruiser 1977 . models 120/140/165/470/888/225/233/350/454 ..
the tools are using the gimbal rings ...so I was taking it of the transom assembly , also do the Mercruiser tool ..the gimbal ring is the wearing of the washers ... I was the Mercruiser mechanic fixing it...of the gimbal ring
model 233 eng 351cu.. the timing engine is 10 deg ...93 octane ... then the 87 octane is changing the engine timing 6 deg ..gasoline ..
also the 10% alcohol is gasoline nasty ...
I did my 1978 merc 470 ...

 

[Bondo]

You need to remove the nut on top of the steering shaft and loosen the tiller arm to drop the shaft out of the gimbal housing.

You're gonna have a tough time finding replacement parts too. You may be able to upgrade to a later style alpha transom assy. The only hangup would be the inner transom plate. It needs to properly connect to the flywheel housing on the engine. Being a Ford it may not be an easy task

Ayuh,..... I'd find a clean used Alpha 1 transom assembly, 'n use the MC-1 inner transom plate with it, if I were lookin' at this problem,.....

 

[dubs283]

use the MC-1 inner transom plate with it, if I were lookin' at this problem,.....

Would be the route I'd go as well however my only issue would be the compatibility of the original inner transom plate with an alpha one gimbal housing.

I guess if it doesn't line up correctly one could ammend the original inner transom plate to work but cannot guarantee it will work correctly/safely

 

[Bondo]

Would be the route I'd go as well however my only issue would be the compatibility of the original inner transom plate with an alpha one gimbal housing.

I guess if it doesn't line up correctly one could ammend the original inner transom plate to work but cannot guarantee it will work correctly/safely

Ayuh,.... The studs/ bolts oughta line up,.....
The depth of spline engagement in the coupler, may, or may not be an issue,.....

 

[dubs283]

The depth of spline engagement in the coupler, may, or may not be an issue,.....

My thoughts exactly, cannot guarantee proper engine alignment by using the old with the newer.

Might be able to fudge it with washers if the situation calls for but then you're getting into fabrication. Not the best/safest route

 

[kenny nunez]

The inner original plate also needs to be compared with the male alinement extension on the Alpha outer gimbal housing. Also the 233’s exhaust down pipe‘s bolt pattern has to be checked that it mates to the Alpha housing.
The Alpha inner plate mounts the steering lower which will not clear the 233’s exhaust down pipe.
I managed to mate a Gen2 gimbal housing to an Alpha 1 drive by using the original bell housing and plugging the speedometer and oil supply holes. I had to use the Alpha down pipe also.
So if a complete Alpha 1 inner and outer were used the the exhaust risers will have to be changed to the inboard style with extension risers to clear the steering and to go straight through the transom and blank off the exhaust outlet on the gimbal housing.
Bottom line, it the original gimbal housing is still good stay with it.

 

[RWVaught]

Here is what I found after prying off the "Mercruiser" label, at the top of the gimbal housing.

It is a 1.25" plug, aluminum I think. Is this so that I can knock this plug out, and get to the upper shaft nut? Is this an access plug?

Also, there are 3/4" plastic pipe plugs, on either side of the upper shaft nut area. I removed those plugs, and there is lots of grease in there.

Should I try to punch that "access plug" inward, like a freeze plug on an engine, and they yank it out with pliers?

Or should I try to drill and tap a hole in it, and then use a slide hammer to extract it?

Thanks,
RW Vaught

 

[flashback]

I'd try the core plug approach first, hopefully you can reuse it..I guess someone has been in there before.

 

[RWVaught]

Well, looks like that plug being removed wasn't the ticket. It lets me see the upper shaft. But, the nut must be above where the grease zerk is. The cross bolt can be removed from the outside by taking out the plastic 3/4" pipe plugs.

So, I will have to pull the engine and get the gimabal ring out, the more time consuming way.

I do have a NOS gimbal ring.

Thanks for the responses!

RW

 

[1960 Starflite]

Thank you for the continued updates. All photos appreciated !

 

[ROY WILLIAMS]

I have a 1975 MC-1 233. I have to replace the gimbal ring. I have the lower gimbal ring shaft out, and the long allen screw at the to of the gimbal ring is removed.

The gimbal ring is loose, but I can't get it clear of the upper shaft (as I pull out on the lower part of the ring). Do I have to remove the gimbal housing, in order to get to the steering lever off of the upper gimbal shaft?

Are there any tricks, or shortcuts I can take here?

RW

MerCruiser 233 1975-1977 Gimbal Ring Assembly & Steering Lever Parts

MerCruiser 233 1975-1977 gimbal ring assembly and steering lever parts. Buy a genuine Mercury Quicksilver or aftermarket part.

www.marineengine.com

look up the diagram and the parts .