89 SN trans noise |
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throttle out
Senior Member Joined: May-11-2015 Location: Chelsea, MI Status: Offline Points: 153 |
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Posted: June-29-2018 at 10:23am |
Hey y'all!
Last night I swapped the trans fluid in my 89SN. My father underneath the boat hosing the shaft & strut bearing I let the boat idle in forward gear to get some circulation and a little heat in the fluid before I sucked it out. When I knocked it in gear it almost sounded like it had some pebbles rolling around in the case. This is the first time I've swapped the fluid like this and the first time I've heard the trans in gear unloaded so this could be normal, just curious what the consensus is. My worst fear was that something is fixing to break in the near future. The trans otherwise performs flawlessly and has the typical PCM40 1.23-1 whine or whirr that they're known for. Thanks in advance! |
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1989 Ski Nautique 2001 351 PCM w/ 1-1.23
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SNobsessed
Grand Poobah Joined: October-21-2007 Location: IA Status: Offline Points: 7102 |
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Could be a bad damper plate. Can you post a recording?
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“Beer is proof that God loves us and wants us to be happy.”
Ben Franklin |
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KENO
Grand Poobah Joined: June-06-2004 Location: United States Status: Offline Points: 10669 |
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What you said It's normal under those conditions |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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Sam,
get it out on the lake for a good test. The rattle you are hearing could be normal. At a low RPM, the planetary gear set will rattle. Did you happen to notice the RPM? |
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Duane in Indy
Platinum Member Joined: October-26-2015 Location: Indiana Status: Offline Points: 1578 |
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Agreed . You tested with absolutely no load on the trans. The prop in the water produces a large loading factor at even 500 RPM. With boat out of the water the shaft is prone to unload and your hearing noise as Pete referred to. Feel the noise will go away when you put it in the water Reply back after your lake test please |
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Keep it as original as YOU want it
1978 Mustang (modified) |
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andrewmarani
Senior Member Joined: May-31-2005 Location: Baltimore, MD Status: Offline Points: 217 |
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I changed out my trans fluid for the first time in years this spring in my 86 SN. Flushed it twice before filling it the final time. I heard the same gravelly noise when the boat was up on the trailer and I put it in forward and reverse to warm up and move the fluid around during each flush.
Used it for the first time Friday to pull the kids and didn't hear anything odd from the trans and it shifted just fine. |
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Builder
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Gneil
Groupie Joined: December-07-2017 Location: Philadelphia Status: Offline Points: 42 |
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Hi Guys,
Thought I might ask a question here even though this trans noise flush has seemed to work itself out..... I own a 1980 SN and had a similar noise / slip when I was running it on my main voyage a couple of weeks ago. Flushed once and replaced the fluid once. Additionally I have replaced the throttle and trans control cables and related misc parts. Upon further inspection, I noticed the trans cooler (5" long with 1" barbs and 3/8" npt fittings original equipment) was slightly damaged due to the previous owner over fighting the cooler bracket, potentially compromising the trans cooler flow..... I have elected to replace the cooler. My question is... might a 9" long cooler be better than the 5" one, all things being the same? I realize these things can't be generalized, but cooler, trans-wise it would seem that cooler is better. |
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G. Neil
1980 SN |
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