The Boating Forum - Volvo Penta SX gimbal bearing issues

I recently purchased a boat with the Volvo Penta SX drive. It recently developed a grumbling sound from the drive that only occured around 2500rpm, and was accentuated in a full turn to starboard. After doing some research I determined it must be a bellows issue with damage to the u joints and gimbal bearing. I removed the drive only to find the u joints appeared fine. The gimbal bearing appears fine from the front, and it turns flawlessly. However, the splines of the drive shaft are rusty between the bearing and the engine. There appears to be no water in the bellows, and not a single rust spot on the u joints or the shaft up to the bearing.

Could water have entered in from the back? I know that alot of water sits in the bilge, and simply forgetting to flip the switch for auto-bilge could have filled it with water. The previous owner had two additional gas tanks on the rear decks totaling 36 gallons. There is also a four-stroke 20hp outboard kicker hanging off the back. When I bought the boat it sat noticably low in the rear. The extra fuel has now been removed.

My plan is to remove the gimbal bearing. I still need to find the correct tool for this. I also understand that I need a tool to install the new gimbal bearing and seal.

I have already ordered the alignment tool needed to put the drive back on. I plan to replace the gimbal bearing and u joint bellows. This is a follow up thread from a previous one that I posted. I feel as though I have encountered a new problem, and a different thread was in order. Thank you to all who have helped me thus far. I would love to get this issue taken care of on my own, not only for financial reasons, but also peace of mind while im bobbing around in the middle of the pacific in a 19ft boat!

Seal is normally installed so it prevents grease from coming out.....I usually flip mine and make it prevent water getting inside - who cares where the grease goes as long as its dry in there. In the pics doesnt appear bellows leaked. You would get visible rust, water in the bellhousing, and in short order your starter would be toast from flywheel spinning sea water into it.

Maybe the steering is a bit out of rig. Turning full starboard may be beyond the capability of the drive and u-joints.

I haven't looked into this.....maybe there is a steering adjustment.

If a turn to full port is OK, I wouldn't be in a hurry to replace u-joints and gimbal bearings that are otherwise dry and turn freely.

In neutral, when you run up to 2000 rpm or so, you will likely hear a bit of a whine and vibration. Again, this is normal, as there is no load on the drive shaft.

Lube the drive splines and reassemble. The other items which comes to mind are bad engine alignment and/or a failing coupler.

Maybe the steering is a bit out of rig. Turning full starboard may be beyond the capability of the drive and u-joints.

I haven't looked into this.....maybe there is a steering adjustment.

If a turn to full port is OK, I wouldn't be in a hurry to replace u-joints and gimbal bearings that are otherwise dry and turn freely.

In neutral, when you run up to 2000 rpm or so, you will likely hear a bit of a whine and vibration. Again, this is normal, as there is no load on the drive shaft.

Lube the drive splines and reassemble. The other items which comes to mind are bad engine alignment and/or a failing coupler.

The grumbling noise was not there during the first 20 hrs or so of me using the boat. I heard the noise at the end of the day after running 3/4 throttle for about an hour or so. It only happens in gear around 2500rpm. I will align the engine when i put it back together. Do you think the bearing could still be bad if I can move it freely with my finger? I have surface rust on the shaft which made me think water got in from the back side somehow. I dont even understand how that could happen. How can I tell if the coupler is going? Thank you for your help!

Just realized that the previous owner told me he hit something recently while underway. I read something that said this could cause coupler failure. Maybe thats the problem?

I developed a knocking noise when moving at low speed and turning hard over either direction. I pulled the drive and inspected the u-joints and gimbal bearing. Both were smooth as silk. I replaced the u-joints based on symptom only, that cured my problem. I grease my gimbal regularly but my u-joints were the permanent lube type. The new ones have zirks so I will grease them whenever drive is pulled in the future.

The only problem I've heard of concerning the drive coupler is slipping which causes severely reduced power and a burning clutch type smell.

I developed a knocking noise when moving at low speed and turning hard over either direction. I pulled the drive and inspected the u-joints and gimbal bearing. Both were smooth as silk. I replaced the u-joints based on symptom only, that cured my problem. I grease my gimbal regularly but my u-joints were the permanent lube type. The new ones have zirks so I will grease them whenever drive is pulled in the future.

So your u-joints looked and turned in your hand perfectly, but where still bad? I really hope this could be the problem. I have not lost power or smelled a burned rubber smell at all when hearing this noise. Thanks so much for your help!

Just used the alignment tool on the drive today, found out the engine was not in proper alignment. The tool would not hardly enter the coupler. After experimenting with the motor mounts a bit, a friend of mine and I were able to correct the problem, hopefully. The tool slides nicely into the coupler now. I assume this had a big part in the problem.

Just used the alignment tool on the drive today, found out the engine was not in proper alignment. The tool would not hardly enter the coupler. After experimenting with the motor mounts a bit, a friend of mine and I were able to correct the problem, hopefully. The tool slides nicely into the coupler now. I assume this had a big part in the problem.

Yes, it will burn the gimble out.

The coupler is easy to check. With motor running look at the back of motor. If drive shaft spinning, out of gear, good coupler. If not spinning blown out coupler.

Slide hammer to remove the gimble and slide hammer in .

Yes, it will burn the gimble out.

The coupler is easy to check. With motor running look at the back of motor. If drive shaft spinning, out of gear, good coupler. If not spinning blown out coupler.

Slide hammer to remove the gimble and slide hammer in .

So to check the coupler I must first put the leg back on?

So to check the coupler I must first put the leg back on?

Yes.

You will see the driveshaft spinning with the drive out of gear with a good coupler.

The sound you are describing sounds like a bad gimble. Change the gimble and replace or grease the u joints.

FYI:
If you start the motor with the drive in the up position you reduce the life of the bearing by as much as half.

You have burn't rubber smell? If not I doubt you have coupler issues? Every alignment issue I have had with stern drives changes with trim and turning. If it is a minor problem it should change when you have no positive or negative trim and outdrive straight.

I always used a 3 leg slide puller to remove and an old 1/2 extension to installed. not to bad if drive is off.

So your u-joints looked and turned in your hand perfectly, but where still bad?


correct

--------------------------------------------------------------------------------

can anyone confirm that these two tools will work, combined with my alignment tool, for my SX-A drive?

http://cgi.ebay.com/ebaymotors/ws/eB...m=370382987219

http://cgi.ebay.com/ebaymotors/ws/eB...m=310221002073

Almost there! Aloha!