Lewmar Ocean ST electric winch new noise

[Jill on Maya]

We have a Lewmar Ocean 48 ST electric winch that we think is 16 years old that we use for hoisting and furling. It intermittently makes a growling noise while under load in electric mode. This is a new development. The winch works as normal in manual mode. The in house engineer/skipper stripped and serviced the winch and replaced the plain bearings in the base and the roller bearings in the drum - no change to the intermittent and distressing noise when in electric mode. He now suspects the problem might be the spindle bearings between the electric motor and the drive gear in the winch. Interested to know whether anyone else has had and fixed this problem. Its quite a job to remove the winch base and we haven't yet searched for availability of any parts likely to be needed.

[skipperpete]

Yes, I have stripped and repaired one of these. The one that had the noise was damaged by water leaking into the 90° worm drive gearbox under the deck, for some reason the worm was plain ol steel and had rusted badly, as had the support bearings. It had reached the point of unreliability so I gave it a new set of bearings and polished out the worst of the corrosion on the worm but it was stowed aboard as a spare and the skipper bought a new lower gearbox. It was an absolute bear of a job because the lower gearbox was corroded in every bolt hole, bearing carrier and shaft, PLUS, it was in the locker in the head so the access was appalling, I declined the request to strip and rebuild the remaining 3 after the battle with the noisy one.

[Jill on Maya]

Happy to report we found (and fixed) the smoking gun. Removed the gearbox, motor assembly and drive spindle - no sign of water ingress or any other issue. But on load testing and with skipper at the motor below deck he realised the noise was coming from the motor itself and the end cap was warmer than expected. On pulling the end cap he found a dry bearing (metal) that was gripping. He cleaned and lubricated the bearing. This stopped the vibration which had loosened the end cap bolts causing the whole motor to vibrate under load and make the distressing noise heard on deck. With the bearing lubricated and the end cap tight, the winch has returned to its usual mode of operation.

[GordMay]

Well done, Jill & Skipper!
I'm always pleased when OPs post follow-ups, describing how issues resolved.

[skipperpete]

Originally Posted by Jill on Maya

Happy to report we found (and fixed) the smoking gun. Removed the gearbox, motor assembly and drive spindle - no sign of water ingress or any other issue. But on load testing and with skipper at the motor below deck he realised the noise was coming from the motor itself and the end cap was warmer than expected. On pulling the end cap he found a dry bearing (metal) that was gripping. He cleaned and lubricated the bearing. This stopped the vibration which had loosened the end cap bolts causing the whole motor to vibrate under load and make the distressing noise heard on deck. With the bearing lubricated and the end cap tight, the winch has returned to its usual mode of operation.

I wish I’d been lucky enough to have a loose motor endcap, …..well done team Maya.