Transmission Fluids

[bturner]

So it's that time of year again and I'm getting ready to put the boat away for the winter. Since the boat is new to me I plan on replacing all the fluids as well as the raw water impeller. Looking through the owner's manual I was able to determine the transmission I had and that Dexron III, or equivalent was the recommended fluid. True Dexron III is near non existent in the wild these days and according to everything I'm seeing on the interweb has been replaced by Dexron VI. I'm also seeing on most products readily available a statement listing compatibility for a multitude of fluid types. This is especially true when looking at Synthetic products like the Mobile One product......

https://mobiloil.com/en/automatic-tr.../synthetic-atf

Or this Castrol product that is readily available off the shelf at the local auto parts stores....

https://www.autozone.com/motor-oil-a...art/930140_0_0

I'm a fan of many of the newer synthetic products as I like to do things once correctly then leave it. I don't put nearly the hours on this boat like I used to so I'm thinking this fluid change will (with me putting 20 hours on the boat a year) easily last me 3 or 4 years. As such the added cost of using synthetic is not going to break the bank. With all this said I'm curious as to what others are using.

[peteSki]

I use the Castrol suff in my 2005 Sport 216, or the Motomaster stuff from Canadian Tire. Both are listed as suitable substitutes for Dex III.

https://www.partsource.ca/products/c...=9819873050671

While I'm also using synthetic, I change mine every 100 hours or annually. I generally put 50-100 hours on the boat per season, so usually I just change it as part of the spring tune up and then don't worry about it. As you say it's minimal cost and easy to DIY.

[bturner]

Thank you for the response. I'm going to try out one of the synthetics this go around. Manual says 2 quarts so kind of hard to pick over a couple bucks going synthetic.

[j2nh]

I would NOT put synthetic transmission fluid in my boat. I have "heard" that the synthetics are too slippery and you will experience slippage.

I do run synthetic in my engine but not transmission.

[scottb7]

I would NOT put synthetic transmission fluid in my boat. I have "heard" that the synthetics are too slippery and you will experience slippage.

I do run synthetic in my engine but not transmission.

Yeah, interesting. I don't know if that is applicable in these as there is only a forward and reverse gear, with gears meshing either forward reverse or neutral based on a mechanical position.

[Infinity]

Is your boat still under warranty? I would consult the dealer or even better...PCM before using something that is not listed as a compatible replacement for DEXIII. You may do more harm than good.
I change my trans fluid every Spring and was able to find actual DEXIII on Amazon or Ebay, the trans in boat is not nearly as complicated as a car.

[GMLIII]

Is your boat still under warranty? I would consult the dealer or even better...PCM before using something that is not listed as a compatible replacement for DEXIII. You may do more harm than good.
I change my trans fluid every Spring and was able to find actual DEXIII on Amazon or Ebay, the trans in boat is not nearly as complicated as a car.

I just use the Advance Auto house brand of DEX III. Inexpensive and easy to find at any Advance Auto stores

https://shop.advanceautoparts.com/p/...smission+fluid

[bturner]

[bturner]

So I bought Mobil One but I do agree with all the comments. The call to PCM is probably the smartest thing to do. The post above is the compatibility statement. Also notice the statement about compatibility with older non synthetic fluids.

Appreciate the responses.

[scottb7]

I kind of doubt a phone call is necessary. Just buy something that meets or exceeds and pour it in...

[scottb7]

This thread reminded me to do mine. No fancy equipment. So easy, maybe 30 minutes for both drain and re-fill.

[j2nh]

Good thread on this over on CorrectCraftFan.com.

http://www.correctcraftfan.com/forum...uid-whats-best

Several commented on not using a synthetic in a wet clutch transmission. Evidently common knowledge in the motorcycle world. No expert just passing on information.

[bturner]

Soooo based on all this I backed out of the Mobil 1 program and went with the Castrol fluid Pete's been using. Easy change and was able to do some over the top cleaning while I had the seat out. Did the ballast while I was there as well. Was going to change the impeller but decided to wait until spring so it doesn't sit in the pump all winter.

Everything is done and the boat is now ready for heated storage.

Thanks for all the comments and suggestions..... Bill