Thrust Bearings and Dripless Shaft Seal

[Matt sachs]

If this is covered somewhere else, I couldn't find it so here it goes. I'm thinking about engine and transmission movement when shifting from forward to reverse, or in rough seas. With a dripless seal, is leakage going to be an issue when the engine shifts towards the front?(or when the prop is in reverse?) I'm thinking about installing a thrust bearing on the shaft and connecting the engine with a splined shaft. Is this necessary, or just something else that will fail at the worst possible time??

[David M]

It's not necessary. Use the transmissions thrust bearing, as is usually the case. Dripless seals have a bellows (like an accordion) that allows for engine movement at the engine mounts as the engine is shifted through forward, neutral and reverse.

[AnchorageGuy]

Matt, I can tell you that we do a LOT of shifting from forward to reverse to maneuver our single engine trawler in tight spaces and when docking. We have the PYI dripless and I love it. I have seen no affects from shifting and it is truly dripless. We have over 1500 miles it it to date. Chuck

[sdowney717]

GFO marine packing is dripless and uses your standard packing gland nut and all. No carbon seals, burping, water injectors. etc...needed.

http://www.gfopacking.com/

GFO® fiber dripless packing is a braided propeller and rudder shaft packing that you can install and forget about. After 15 years of successfully handling demanding industrial pump applications, it's now proving itself in the marine field, too. It's already being used by the US Navy and Coast Guard and many commercial work and fishing fleets. And, it's approved by the American Bureau of Shipping.

[Matt sachs]

Thanks guys. Thats what I needed to hear.

[Rimica]

I have an issue with my Volvo Dripless Shaft Seal - Stuffing Box.
Worked fine for a few years with proper maintenance etc. This year however it started to make noise in a specific rpm range (2,000 to 2,700 rpm). The sound is similar to an alternator belt slipping.

It is properly greased and burped.

Any thoughts?

Thanks

[Vasco]

Originally Posted by Rimica

I have an issue with my Volvo Dripless Shaft Seal - Stuffing Box.
Worked fine for a few years with proper maintenance etc. This year however it started to make noise in a specific rpm range (2,000 to 2,700 rpm). The sound is similar to an alternator belt slipping.

It is properly greased and burped.

Any thoughts?

Thanks

Is it leaking? Are you sure it's the shaft seal making the noise? I think there's a cutless bearing aft of the seal.

[Rimica]

Originally Posted by Vasco

Is it leaking? Are you sure it's the shaft seal making the noise? I think there's a cutless bearing aft of the seal.

There is no leak. Everything is dry as a bone. I will check the bearing wear once I am hauled out. Thx