SYNTRON SHAFT SEAL MAINTENANCE

Engines, Drive trains, Propellers, Steering, Ground Tackle and other mechanical system
Post Reply
pelagic
Posts: 22
Joined: Sat Sep 11, 2021 3:19 pm

SYNTRON SHAFT SEAL MAINTENANCE

Post by pelagic »

My M 28 w/ 2GM 20 F has been out of the water in 8 yrs, and I assume the shaft log is original. I hesitate to launch w/o maintenance to the seals. https://www.munacosealing.com/products/ ... haft-seals says they have repair kits, which can be installed in the field. I have checked the posts, and find nothing on this. Has anyone had experience w/ this? I don't want to pull the shaft and possibly damage the seals without having a repair handy. I will contact the company next.
Thanks, John

rafontaine1
Posts: 44
Joined: Sat Dec 27, 2008 11:34 am
Location: Liberte, F36, 1986, Portsmouth RI

Re: SYNTRON SHAFT SEAL MAINTENANCE

Post by rafontaine1 »

In 2019 I decided to replace the Syntron Shaft seal with a Norscot Shaft seal for at least half the price ($350) of a Syntron seal rebuild kit. Plus the lead time was longer than I could tolerate. It is a good seal but requires external lubrication from a reservoir using transmission fluid. I figured this would be better than using seawater lubrication as it would be much cleaner and less corrosive. So far I am happy with it. Tight fit but was able to get it in with room to spare. Freedom started using this shaft seal on some of its newer models back when in production.
Rich Fontaine
s/v Liberte
Freedom 36, 1986
Portsmouth, RI

User avatar
rvivian
Posts: 204
Joined: Sun Feb 21, 2010 2:08 pm

Re: SYNTRON SHAFT SEAL MAINTENANCE

Post by rvivian »

Do not install a Norscott seal as when it fails it dumps transmission oil into the ocean.

Contact Warren boat Works for a custom cut dripless seal.
Heart's Desire
Freedom 30
Shelton, WA

User avatar
GeoffSchultz
Posts: 1111
Joined: Thu Dec 04, 2008 8:39 am
Location: BlueJacket: Guatemala
Contact:

Re: SYNTRON SHAFT SEAL MAINTENANCE

Post by GeoffSchultz »

You shouldn't need a custom shaft seal. The PSS shaft seal has worked great for me.

-- Geoff
BlueJacket
1997 Freedom 40/40
http://www.GeoffSchultz.org

User avatar
RadioZephyr
Posts: 218
Joined: Mon Jun 27, 2016 10:04 am
Location: Boston, MA

Re: SYNTRON SHAFT SEAL MAINTENANCE

Post by RadioZephyr »

GeoffSchultz wrote:
Wed Jan 19, 2022 5:45 pm
You shouldn't need a custom shaft seal.
It's not a custom shaft seal, just a modified version of the Tides Marine seriesOne seal. The hose for the seal is cut down slightly, I think, so that it will fit in the very small space between the engine and the stern tube. From what I understand, a PSS seal won't fit in most Freedoms, which is why they went with the Syntron, and later the Norscot. I have had both a Norscot and a Tides, and the Tides seal is so much better.

The main problem with the Syntrons, which were selected by Gary Mull when he was designing the F36, is that over time the graphite in the seals wears grooves into the shaft where they make contact. It will start to leak, and the owner will think the seal needs to be rebuilt, but the problem remains because the shaft is damaged. I believe this is what prompted the switch to Norscot.
Josh
Sunset Spy
F38, Hull #152
Boston, MA

User avatar
bobr
Posts: 112
Joined: Wed Jul 22, 2009 5:05 pm

Re: SYNTRON SHAFT SEAL MAINTENANCE

Post by bobr »

My yard was able to install a PSS shaft seal on my 35. I've done the job on another boat, but it looked like a very tight fit so I let them do it. They said it took longer than expected, and I can believe it.
Bob R.
1995 Freedom 35 (Pedrick)
"Liberty"
Old Saybrook, CT

User avatar
Camino
Posts: 316
Joined: Fri Oct 28, 2016 4:51 pm
Location: Stockton, CA

Re: SYNTRON SHAFT SEAL MAINTENANCE

Post by Camino »

I have a P 35 - on my second pss shaft seal. No problems. Uncompressed length of the seal is approx 6 3/4”. Compressed is less :D Measure and check your available room….
Tom and Stephanie
Good Way II F 35 (P)
1999. Wing Keel 5’
3GM30F, 3-blade maxi prop
Emery Cove, CA

pelagic
Posts: 22
Joined: Sat Sep 11, 2021 3:19 pm

Re: SYNTRON SHAFT SEAL MAINTENANCE

Post by pelagic »

Thanks for all the useful info, I will check all the options, starting with Warren River Boatworks, which I didn't know about.

Post Reply