Gimbal bearing replacement

[Highland bear]

Hi All , Having only recently got into boats , I have a Maxum 180 SR, the gimbal bearing , bellows etc were all replaced prior to purchase, I would estimate it has only run 50 hours , and last time out it was a bit noisy and a lot of smoke coming from back of engine ( no flame) more a hot metal type thing , got the company I bought it from to give it the once over , they came back with gimbal bearing faulty, my response at best was Hmm !! I suspect maybe was not done , or fitted incorrectly, either way a bit suspicious , before retiring been on the tools all my days , engines, transmissions, hydraulics etc but not much to do with boats , question to be asked , Is this a DIY job to get to this bearing ?

[mmwjr]

If you have been turning wrenches for years it should be a job you can do. Go to the "Documents" tab at the top of this WEB page. Then go to Mercruiser manuals and look for the Alpha manual.

Basically the drive needs (shifter in forward) to be removed then using a slide hammer with outward claws is used to pull the bearing. If the replacement is not the lubed for life one be sure the grease hole is aligned with the grease fitting in the housing.

However I would first check the condition of the bellows for cracks as if the bearing wasn't replaced or it was done years ago the bellows condition is suspect to me.

[mmwjr]

Forgot to mention is the bellows are bad then it's time to rebuild the entire transom assembly; bellows, bearing, shift cable, trim limit and position sender. Also check steering for too much play as the swivel shaft may be worn.

[Highland bear]

Originally Posted by mmwjr

If you have been turning wrenches for years it should be a job you can do. Go to the "Documents" tab at the top of this WEB page. Then go to Mercruiser manuals and look for the Alpha manual.

Basically the drive needs (shifter in forward) to be removed then using a slide hammer with outward claws is used to pull the bearing. If the replacement is not the lubed for life one be sure the grease hole is aligned with the grease fitting in the housing.

However I would first check the condition of the bellows for cracks as if the bearing wasn't replaced or it was done years ago the bellows condition is suspect to me.

Hi Thanks for info, I was informed there was quite a bit of work to be done prior to buying boat , the visible stuff I can see has been changed, it was meant to have been serviced oil /filters done but spark plugs were a no , I am a bit suspicious of it all , if bellows/bearing had been changed why has it packed in after approx 50 hours also grease fitting for bearing has been blanked off , I will have it apart and have a look in the hole , how long a shaft on the slide hammer required ?

[mmwjr]

I'm sure have heard the line trust but verify, frankly when it comes to boats I only trust myself.

Remove the dipstick, is the oil clean? Does the filter look new?

Remove the lube drain plug for a few seconds to capture some lube in a jar to look for signs of water (bad seal), metal shavings (worn gears or bearings).

Use an IR temp sensor to take reading on the engine as well as exhaust components which are water cooled (helm gauge only reflects engine temp near the t-stat).

A standard slide hammed bar should work. With drive removed depth to bearing is about 12".

The newer models did not have the grease fitting as they coming with a lubed for life bearing. ~ > 2000

PS the bearing would only fail that so if water (bad bellows or very high bilge water) was getting to it.

[Highland bear]

Originally Posted by mmwjr

I'm sure have heard the line trust but verify, frankly when it comes to boats I only trust myself.

Remove the dipstick, is the oil clean? Does the filter look new?

Remove the lube drain plug for a few seconds to capture some lube in a jar to look for signs of water (bad seal), metal shavings (worn gears or bearings).

Use an IR temp sensor to take reading on the engine as well as exhaust components which are water cooled (helm gauge only reflects engine temp near the t-stat).

A standard slide hammed bar should work. With drive removed depth to bearing is about 12".

The newer models did not have the grease fitting as they coming with a lubed for life bearing. ~ > 2000

PS the bearing would only fail that so if water (bad bellows or very high bilge water) was getting to it.

Hi Thanks for info , all afore mentioned fine , the only one thing that might be an issue to contribute at one point end of last season I forgot to leave hull drain plug out and we had really heavy thunderstorms , boat had a LOT of water in it when I drained it

[mmwjr]

Did the water get up to the starter, alternator? As these could be damaged if submersed.

[Highland bear]

Originally Posted by mmwjr

Did the water get up to the starter, alternator? As these could be damaged if submersed.

Morning , No it was not up that far , this incident was also quite a while ago, boat was running fine until the last trip out last year when fault occurred , limped back to harbour and took it out of the water and into storage over winter

[mmwjr]

BTY I have never heard of a bad gimbal bearing resulting in smoke. Melting exhaust coupler from lack of cooling water will cause this.

[Highland bear]

Originally Posted by mmwjr

BTY I have never heard of a bad gimbal bearing resulting in smoke. Melting exhaust coupler from lack of cooling water will cause this.

Hi I did think this a bit odd, possibly bearing turning in housing certainly worth a look engine did not overheat could it be the pump failed ?

[mmwjr]

Originally Posted by Highland bear

Hi I did think this a bit odd, possibly bearing turning in housing certainly worth a look engine did not overheat could it be the pump failed ?

See post #5 about checking things with an IR temp sensor.

[Highland bear]

Hi How is the exhaust coupler cooled ? what should I be looking for ? boat still in storage just now , will be getting it out shortly, your statement does make sense , there was a lot of smoke but no real noise if the bearing failed probably would not have managed to drive it back to the harbour , just kept engine at idle with engine cover open and got it back , smoke cleared by time we got to harbour

[Phillbo]

Exhaust Coupler ?

[mmwjr]

Originally Posted by Phillbo

Exhaust Coupler ?

Rubber hose from the elbow/riser to y-pipe.

[mmwjr]

Originally Posted by Highland bear

Hi How is the exhaust coupler cooled ? what should I be looking for ? boat still in storage just now , will be getting it out shortly, your statement does make sense , there was a lot of smoke but no real noise if the bearing failed probably would not have managed to drive it back to the harbour , just kept engine at idle with engine cover open and got it back , smoke cleared by time we got to harbour

The exhaust manifolds are double walled with the inner part being for the exhaust gases and the outer compartment for cooling water. The elbow/riser is the same way except the output section the cooling water is injected into the exhaust stream to cool it before going through the rest of the system and overboard. The black rubber hose will turn whitish it overheated from a lack of water.

[Highland bear]

Originally Posted by mmwjr

The exhaust manifolds are double walled with the inner part being for the exhaust gases and the outer compartment for cooling water. The elbow/riser is the same way except the output section the cooling water is injected into the exhaust stream to cool it before going through the rest of the system and overboard. The black rubber hose will turn whitish it overheated from a lack of water.

Morning Thanks for info , greatly appreciated, will be getting boat out of storage so will get in about it to see what's going on

[MoonRiver]

when you say smoke from rear of engine, what type of smoke was it? did it smell like steam heat, oil, rubber, or electrical?

I blew a drive coupler a number of years ago while u/w. I don't remember smelling or seeing smoke but shifting into gear was noisy and clunky leading up to the total failure and no going forward or reverse.

[Highland bear]

Originally Posted by MoonRiver

when you say smoke from rear of engine, what type of smoke was it? did it smell like steam heat, oil, rubber, or electrical?

I blew a drive coupler a number of years ago while u/w. I don't remember smelling or seeing smoke but shifting into gear was noisy and clunky leading up to the total failure and no going forward or reverse.

Morning Difficult to say about smoke , was not electrical that was my first reaction when I seen it , then decided it was something running very hot at the back of the engine , it was hot so good not get down the back of it to see , limped home at idle, it has been mentioned here about the rubber exhaust coupler, which kind of makes sense as i left engine cover open until we got it back to harbour, smoke mostly dispersed so may have been exhaust smoke, planning on getting it out of storage soon

[MoonRiver]

When you say limped home at idle, was that due to low/no power, rising engine cooling temp? Not that the dash mounted temp gauge is accurate, but what did read while this was happening? At idle did the temp come down or at least stay steady? Did the temp rise when you increased rpm's?

You might have a bad impeller!!! I had a 5.7L merc and the impeller was (facing aft) down low on the left side under the water pump. Not very easy to get to. My guess is the impeller came apart and the pieces got very hot and smoked. These pieces can cause all sorts of issues and damage. In you case the pieces going through the system could have damaged the flapper valves in the exhaust piping (just prior to the Y pipe).

[Highland bear]

Originally Posted by MoonRiver

When you say limped home at idle, was that due to low/no power, rising engine cooling temp? Not that the dash mounted temp gauge is accurate, but what did read while this was happening? At idle did the temp come down or at least stay steady? Did the temp rise when you increased rpm's?

You might have a bad impeller!!! I had a 5.7L merc and the impeller was (facing aft) down low on the left side under the water pump. Not very easy to get to. My guess is the impeller came apart and the pieces got very hot and smoked. These pieces can cause all sorts of issues and damage. In you case the pieces going through the system could have damaged the flapper valves in the exhaust piping (just prior to the Y pipe).

Hi I just ran it at idle to get it back temp gauge stayed constant,will investigate your theory when I get it out of storage ,thanks for your input