By: Frank Lanier
I have a 1988 23-foot Sea Ray with a 260 hp MerCruiser and an Alpha One outdrive. Two years ago, I had the outdrive resealed and the water pump replaced. It was used last summer for the first time, and at idle there is a metallic ticking when the wheel is full left or right; otherwise, there’s no noise. The maintenance department is no longer at the marina. Any ideas?
The likely culprit that springs to mind is a bad or failing U-joint; however, that’s not the only prospect. A defective gimbal bearing can also cause the symptoms you describe (a failure often caused by water intrusion into the bellows). That being said, a bad gimbal bearing will often make noise anytime the engine is running, while a faulty U-joint typically makes itself heard when the drive is tilted up or turned to port or starboard, which forces it to articulate as the angles change.
Finally, another often-overlooked possibility is poor alignment. A misaligned drive axle/U-joint can cause noise (as well as binding and damage in some cases) due to the lateral stress generated from being at a slight angle.