Lift motor advice please....

[glen e]

Had my annual inspection on my lift this week and found out the stbd gearbox is slowly leaking oil out the front seal. The type of lift motor is this:

the gears actuated by the wheel are worm type to a larger std gear:

the seal on the front is leaking gear oil:


The lift company says the gear box is under warranty and they will replace it no questions asked. However they said to not use it "too much" unitl I get the new gearbox. Huh? It gets used 3 -4 times a week. So there fore I took the gearbox plate off while the lift was all the way down and there is plenty of gear oil in there, I'm gonna add some more thru a vent hole in the top. Gears look to be in great shape and are bathed in hypoid oil.

My question is this:

the lift guy said if it gives way it'll just lower the boat in the water....huh? just one side would go down which I think would be disasterous. To do that would not the gears have to give way?..and in this set up, if the belt breaks does it unwind? - or does the worm design protect against that?

thanks in advance....

[welder]

Is there two motors on your lift ?

Glen with a very nice boat like yours I would set it in the water [ or very close to it ] till the lift is running properly.

Lester

[glen e]

yes two motors...and yes..it hovering right above the water....

[darbikrash]

Can't really see from your setup how the gear drives raise and lower the load, but if the belt breaks, nothing should happen. Worm gears are typically 120:1 reduction (or something like that) and will not backdrive. So they wouldn't budge.

If a gear galls, snaps or breaks due to lack of lubrication, not sure if the load would drop, but it probably would. You would expect to hear some horrible squealing from that gear train well before anything broke, if lack of lubrication were the issue.

You'd have plenty of notice before anything serious happened with those slow speed gears.

[welder]

Are the tides going to mess with ya.

Lester

[glen e]

Originally Posted by darbikrash

Can't really see from your setup how the gear drives raise and lower the load, but if the belt breaks, nothing should happen. Worm gears are typically 120:1 reduction (or something like that) and will not backdrive. So they wouldn't budge.

If a gear galls, snaps or breaks due to lack of lubrication, not sure if the load would drop, but it probably would. You would expect to hear some horrible squealing from that gear train well before anything broke, if lack of lubrication were the issue.

You'd have plenty of notice before anything serious happened with those slow speed gears.

John - Jim Z and I looked at it that way and were coming tothe same conclusion - There is a ton of oil/grease still inthere and the gears are still lathered in the brown gel...If I want to just keep it filled with oil/grease thru a top hole, what spec would you receommend? I'm thinking 90 weight hypoid gear oil - or something thicker in a tube that would not leak as fast?

[jenkinsph]

If the seal is the problem just keep it full untill they can replace it. If you wind up having to dealwith it yourself try Motion Industries they should have the parts needed within a couple of days if not in stock.

Is there shaft play or just seal failure?

As long as the shafts are okay the worm gear will not allow the cable to unwind.


Steve

[glen e]

Originally Posted by jenkinsph

If the seal is the problem just keep it full untill they can replace it. If you wind up having to dealwith it yourself try Motion Industries they should have the parts needed within a couple of days if not in stock.

Is there shaft play or just seal failure?

As long as the shafts are okay the worm gear will not allow the cable to unwind.


Steve

just seal failure.....no shaft play and bearings are perfect...

[jenkinsph]

Then if the bearings are good I wouldn't worry much, just use it. Those seals are on
the low speed shaft that turns very slow, should not be a problem while waiting a month
for the new stuff.


Steve

[Kern O]

I'm going to jump in with the same sort of comment. The seal leak is completely different from a gear failure and I'd expect the two to be unrelated until you ran out of oil. Then they could get related.

For the seal to have gone out this soon says that there may be a mis-alignment between the shaft and the seal. But the extent of the problem in the foreseeable future is nothing more than a drool of gear oil. It appears to be on the output shaft (the slow speed shaft) rather than the input shaft. From looking at the pictures, everything is well slathered in grease, so it is hard to see how much it is leaking.

Here's the big question: Is there a cross shaft that ties both ends of the lift pulleys together? I'd sure think there should be one so that both ends of the lift move at the same speed.