F36 Syntron shaft seal

[maxpbd]

My 1988 F36 has a Syntron shaft seal. I hauled and bottom painted to boat last week, and while out of the water greased the Syntron seal. (My Freedom owners manual states that the only maintenance the Syntron needs is occasional grease through the grease fitting on the sea.) About four hours into my motoring back to Friday Harbor I started to hear a scraping or squeaking sound like a shaft might make while turning if a bearing on the shaft wasn't adequately lubed. If I put the transmission in neutral and waited a few seconds, the squeaking stopped, but would start again as soon as I put it into gear again. Ålthough the owners manual says to grease the Syntron seal, some older posts on the Yahoo Freedom site (Fargo Rousseau being one) state that the seal SHOULD NOT be greased, that sea water lubricates the seal and that grease blocks the sea water. If that is the case, the fix is apparently to try to "de-grease" the seal with a solvent. Temporally, this explanation makes sense, as this is the first time I have ever greased the seal, and the sound showing up after four hours of motoring (although I'm not sure it is the shaft making the sound) would suggest that the seal heated up after that much use and started to squeak. Has anyone had any similar experience that might shed some light on this or know something about the "to grease or not to grease" question?

[Michel]

Max,

I don't know the exact design of the Syntron shaft seal, but could it be possible that the seal has to be bled after the boat has been out of the water? I had similar problems (plus heavy leakage) with the Volvo Penta maintenance free rubber lip seal after the boat was taken out. The Volvo Penta lip had to greased with a smear of silicone grease once a year. To bleed, you had to pinch the rubber bellows to make it 'burb'.

[AlanK]

I don't know anything specific about the Syntron. I have a PSS shaft seal. Here is some information on it in case its relevant.
1. There is no grease nipple. The lubrication is seawater.
2. The system needs to be "burped" when put in the water to void air. This is done simply by pushing back on the rubber bellows until water comes in. The newer models have a fitting to which you can run a tube above the waterline and then air is automatically bled out. This is required for planing boats.

[mike cunningham]

Here's a link to the Syntron shaft seal description. Your interested in the mechanical shaft seal. Drawings are provided.

http://www.fmctechnologies.com/upload/shaftseals.pdf

Synton engineers will talk to you if you call and are pleasant