Synthetic oil gt40

[DanielC]

I have been using Valvoline Dexron III in my transmission. Change it every other engine oil change, and at the end of the season. I am switching to a Dexron/Mercon formula, since Dexron III is getting hard to obtain. The ATF comes out of the transmission still looking very good. Transparent red color. My boat has 1975 hours.
I am on a show ski team, and I use my boat quite often for pulling 6 to 10 girls in a chorus, or ballet line, the boat quite often pulls 4 people in the jump acts, 4 to 6 people in around the boat acts. and occasionally, 9 or 10 people in pyramids. Other times ois is only pulling a single girl on a swivel ski. I have also occasionally used my boat for towing jump ramps, and the floating dock we use.
Long story short, I probably have more hours on my 1997 Ski Nautique than most of you do, argueably working harder at least some of the time than your boat has, and I use conventional transmission oil. I have not overloaded my boat with ballast, for wakiboarding, although.
I have said it before, concerning the engine. Valvoline VR-1 40w oil, Motorcraft FL1-A oil filter.

[bchesley]

For PCM to just blanketly say no to synthetics and that they are just too slick does not really add up. How can you say that about every synthetic fluid. Not all fluids are the same. If the RP ATF is formulated like a DexronIII the properties of the fluid are the same. How could that be bad.

[wakeboard1]

I use Mobil 1 15-50. Like stated, it is intended for high performance engines and contains 1200 ppm of ZDDP.

[Quinner]

For PCM to just blanketly say no to synthetics and that they are just too slick does not really add up. How can you say that about every synthetic fluid. Not all fluids are the same. If the RP ATF is formulated like a DexronIII the properties of the fluid are the same. How could that be bad.

There is a tranny rebuilder, Eric Lavine, who is on CCFan quite a bit, he has always said synthetics are no good for the trans, that and what TR mentioned with regards to his conversation with PCM would make me think twice before using synthetics in my trans.

[DanielC]

I am going just to make a wild guess on how an oil or fluid gets approved for a particular use, in a car, boat, transmission, or whatever.
Designers, and engineers decide on what characteristics they want the fluid to have. It must lubricate the parts, it must seal piston rings in an engine, it cannot harm gaskets, it needs to keep O rings soft, but not degrade them. It has to be able to disperse wear particles. In the case of transmissions, it has to allow chutches to slip, when the transmission is just going into gear, but hold tight after the transmission is fully in gear.
After testing oils, or fluids that they think will work, and give acceptable service, when they find one, that is what they recommend. No need for further testing.
I am pretty sure that they do not retest every new formula of oil, or transmission fluid that comes along, just to see if it will work. If they already know what works, why spend the money for additional unnecessary testing of every new oil that comes along.
If you want to run a different type of oil in your engine or transmission, that is your choice. It may cause problems, it may not. If you want to run a type of oil not tested by PCM in your transmission, go ahead. You might be OK, you possibly might not.
If the new type of oil you insisted on running causes your transmission to need service, and you are running an non approved oil, PCM has a very good ground to stand on to deny you warrenty service. The manufacturer of the non approved oil, might warrenty your transmission work, or they might not. Even if the transmission service is covered by one warrenty, or another, I can almost guarentee you will not be compensated for time lost while your boat was being serviced.
I do not understand why, when faced with a choice of lubricants, some approved, and some not, you would choose a non approved one, just because the sales man trying to sell it to you says is it better.

[bchesley]

No salesman involved and my boat is 11 years old with no warranty. I can understand your point if I was going to use a synthetic Type H fluid or a synthetic Type A fluid and the fluid was truly not designed to work in the tranny. The Max ATF is a fluid that has the same properties of Dexron/Mercon, it just happen to be a synthetic version. I am going to email the manufacturer and see what they say.

[TRBenj]

The Max ATF is a fluid that has the same properties of Dexron/Mercon, it just happen to be a synthetic version. I am going to email the manufacturer and see what they say.

Remember what the fluid was designed for- AUTOMATIC AUTOMOTIVE transmissions. Our wet clutch marine transmissions are very different animals- there are no wet clutches in an automotive autobox- they rely on pumps and fluid pressure, not friction. Our boxes are more closely related to wet clutch motorcycle transmissions- I think if you do some research you will find that many people have found that synthetic ATF decreases the life of those gearboxes as well.

I would follow the recommendation of marine transmission experts and their manufacturers over that of the fluid reps- but feel free to report back with what you find out.

[Christopher-W.-Becker]

All,

Rebumping this thread........

I have learned that many of the diesel oils such as ROTELLA have been removing the metals to comply with the emission requirements of the 2007 and new deisel engines with filters and that this oil may not be suitable for older diesels such as the older NAVISTAR in my 2001 Excursion and 1996 F350. I a discontinuing use of Rotella (T is the synthetic) unitill I confirm and going back to a 15W40 oil that is not compliant with API-CJ4 rating (see http://www.upmpg.com/motor_oil_rate_gas.htm) and would like to find a AH-4 oil since we dont have emission controls issues. The soot controll additives for the boat are great as boats spend a lot of time "city driving" and with only 5 quarts in the system the carbon loads faster than a regular gas engine. Changing often is the best remedy...I know and I do.

Any oil engineers out there want to weigh in techincally.