Synthetic auto trans fluid

Tranny fluid has anti foam roperties which you need in theses trannys over 2600 rpm.
That is input rpm as in engine rpm.
That is from BW.

I belive the anti-foaming additive is the primary reasom to use trans oil.

True on the anti foaming, but the assistance boats I run with BW transmissions all get the hell beat out of them.

They are coupled to 454 gas engines that run well up over 3600 RPM and run on straight 30 weight...and have for decades.

So like many oil threads....maybe a lot less is critical than what many posters think.

psneeld said:

True on the anti foaming, but the assistance boats I run with BW transmissions all get the hell beat out of them.

They are coupled to 454 gas engines that run well up over 3600 RPM and run on straight 30 weight...and have for decades.

So like many oil threads....maybe a lot less is critical than what many posters think.

Click to expand...

I find it interesting that two substantially different fluid compounds [i.e. motor oil and transmission fluid] run neck n' neck in experienced boater's opinions for working best in BW VD marine transmissions.

From what I understand the most recommended fluid for BW VD trany [back in the day] was a Ford trany fluid, I forget the number affixed to it.

Talking with my decades trusted transmission rebuilder as well as some knowledgeable marine mechanics and from learning [readings] in forums I have stuck with Dextron III. Sure stays clean looking and our two BW VD tranys work well.

I just don't understand how very slippery [and I believe somewhat compressible, lubrication prone] motor oil in contrast to not so slippery [and I believe not at all compressible, hydraulic prone] trany fluid can each perform as well as so many say in the same transmissions.

Am I missing something here??

Cheers!

Art said:

I find it interesting that two substantially different fluid compounds [i.e. motor oil and transmission fluid] run neck n' neck in experienced boater's opinions for working best in BW VD marine transmissions.

From what I understand the most recommended fluid for BW VD trany [back in the day] was a Ford trany fluid, I forget the number affixed to it.

Talking with my decades trusted transmission rebuilder as well as some knowledgeable marine mechanics and from learning [readings] in forums I have stuck with Dextron III. Sure stays clean looking and our two BW VD tranys work well.

I just don't understand how very slippery [and I believe somewhat compressible, lubrication prone] motor oil in contrast to not so slippery [and I believe not at all compressible, hydraulic prone] trany fluid can each perform as well as so many say in the same transmissions.

Am I missing something here??

Cheers!

Click to expand...

I rebuilt one of mine years ago, and they are very simple inside unlike a car trans with lots of electronic solenoids and switches. Basically gears, an oil pump and a set of clutch plates. I had a leak from rust forming on cast iron, which distorted a large square O-ring, none of the internals was anything but great looking. Trans is OEM from 1970, figure out why nothing was wrong, because they work a long time.

High heats destroy ATF fluids and oils, seals, clutches, and these boat trans don't get that hot, unless in a humongous HP app. So the oils stay clean looking.

One fault is most have to spin with engine rotation and can not reverse rotation the prop continually. Another is they have lower torque-hp limits with diesels since the diesel slams the pistons harder on combustion than gas.

Art said:

I find it interesting that two substantially different fluid compounds [i.e. motor oil and transmission fluid] run neck n' neck in experienced boater's opinions for working best in BW VD marine transmissions.

From what I understand the most recommended fluid for BW VD trany [back in the day] was a Ford trany fluid, I forget the number affixed to it.

Talking with my decades trusted transmission rebuilder as well as some knowledgeable marine mechanics and from learning [readings] in forums I have stuck with Dextron III. Sure stays clean looking and our two BW VD tranys work well.

I just don't understand how very slippery [and I believe somewhat compressible, lubrication prone] motor oil in contrast to not so slippery [and I believe not at all compressible, hydraulic prone] trany fluid can each perform as well as so many say in the same transmissions.

Am I missing something here??

Cheers!

Click to expand...

Yep....missing something.

Probably flyshi* to the transmission either way.

Maybe the disbelief that oil works is the slow mindset since the coming of auto transmissions.

I am no tranny guy....but my experts, including my Borg Warner manual says motor oil is just fine. Mine stays clean for years until change.

If oil works fine in the engine components...why wouldn't it work just fine in a low tech tranny? Maybe better.

psneeld said:

Yep....missing something.

Probably flyshi* to the transmission either way.

Maybe the disbelief that oil works is the slow mindset since the coming of auto transmissions.

I am no tranny guy....but my experts, including my Borg Warner manual says motor oil is just fine. Mine stays clean for years until change.

If oil works fine in the engine components...why wouldn't it work just fine in a low tech tranny? Maybe better.

Click to expand...

I don't know... that's why my question.

Guess I'm confusing what happens inside marine trans, such as a 1977 OEM BW VD and an auto trany, such as OEM in a 1960's muscle car or even a 1980's HD 1 Ton pick up truck. I know a bit about those vehicles transmission internals.

If I put motor oil in my 1967 Buick Wildcat auto trany that would not at all work... I'd be looking for a replacement!

As you can probably tell, I'm not well versed on marine trany internals. My decades in business trany shop takes care of all my tarns needs. Many years ago the owner was national trouble shooter for GM's main HQ. He designed some of the transmissions that made GM race cars fly on the race tracks and had a hand in designing transmissions [both auto and 4 spd standard] for late 1960's to mid 70's Chevrolet Corvettes.

Ever look at the inside of the "brain" that makes an auto tranny work?


Tiny parts that need very low viscosity fluid...


Plus, I am not sure about the rubber drive components in a velvet drive, but the planetary gears and drive band probably prefer oil over fluid, but not sure about how much friction the band to reverse gears needs to grab. The gears may prefer oil and the friction components may prefer trans fluid. As I said there may be an overlap that the tranny could care less about.


Anti foaming is important....but not sure why the assistance tower maintenance guy still used oil with 454 gassers. But sure can argue with his performance record. The way thse trannies got treated made recreational use look line non-use.

The enemy of good is better.................

Marlinmike said:

The enemy of good is better.................

Click to expand...

I Like That Profoundly Simple Statement!!!

And... a big PIA when I at times keep trying to reach the word "Better"

Old saying: "Perfection can be strived for but seldom if ever attained".

Another way of looking at it: Closer you get to perfection [such as something like reaching speed of light] it gets more and more difficult due the ever increasing resistance-mass you'll encounter!

Sort of not to dissimilar to trying to get a full displacement hull up onto plane. :lol:

The million dollar question in these forums often is...what truly IS better?

That is usually the million dollar question on these forums..."what is truly better?"


It isn't like we haven't seen small incremental changes in lubricants through the years...


Or the changes in business models where "service" at the dealership or throw aways is the mantra rather than sell it with the promise that proper maintenance will make it last a lifetime.

psneeld said:

The million dollar question in these forums often is...what truly IS better?

Click to expand...

I'd say "Better" is what works best/OK for each of us.

Not our "first day on the beach"... so to say... regarding many of us contributing to this forum.

It is great though to be able to read sooooo many accounts of what is "Better" for other experienced boaters/marine officisiandos!

No doubt that via this or other forums' posted input I have changed or modified or even began new procedures to enhance ease and joy of pleasure boating.

However as I recall the manufacturer specs ATF and says engine lube oil is ok under certain circumstances.

Nomad Willy said:

However as I recall the manufacturer specs ATF and says engine lube oil is ok under certain circumstances.

Click to expand...

Read carefully, my manual...but not all the manuals says 30WT or 40WT is OK if under 3000 engine RPM.


Maybe BW like many other manufactures don't trust the average owner to actualy listen to that advice and recommend the inferior product so one size fits all......


Anyone here know WHY BW recommends tranny fluid most of the time? Is it ACTUALLY better or just a better bet?

Maybe I wouldn't be so cavalier about it if I didn't beat the crap out of a fleet of boats running 30WT with about as much torture as anyone here could do to their trannys in 1000 years.

My own tranny has gone at least 5000hrs on 30Wt and runs flawlessly.

Like I said...the tranny probably prefers one lube for part of it and another for the other parts. Being gentle with them allows them to run for ever on either fluid....but I know for a FACT that 30WT kept commercial service Borg Warners running when many here xouldn't imagine them doing so.

Not to be slanted, but I am.
I use our 204SAT full synthetic in my CR2 velvets.
Compatible with many trans types and very stable. Excellent heat transfer for cooler operation, and great bearing lubrication.
I can send you a tech sheet by email if you like.

..and exceeds the need on Allison TES295 and 389 (transynd)

One thing I can say for SURE is that my replacement clutches are a different material than oem.
So why not upgrade the lubrication?
I did. My tranny loves me more lol

jlenord,
I don't have the original type clutch plates either but the people that rebuilt the gear recomended ATF.

Oil is not like a car that can have more bells and whistles. The only way you can "upgrade" your lube oil it to find and impliment more suitable oil. So many thousands over the years have had excelent results w ATF (and it's recomended) that I see an "upgrade" as being imposible. How can you do better than perfect? And if you change most anything there are downsides. There's even less to gain than w syn in an FL engine.

I can't get over the chance that there's something, some quality or feature of this "upgrade" lubricant that isn't as good for the trans as ATF. Not particularly but like seal swelling. New mousetraps may trap the cat. Would you drink "new" Coca-Cola? Why?

Nomad Willy said:

jlenord,
I don't have the original type clutch plates either but the people that rebuilt the gear recomended ATF.

Oil is not like a car that can have more bells and whistles. The only way you can "upgrade" your lube oil it to find and impliment more suitable oil. So many thousands over the years have had excelent results w ATF (and it's recomended) that I see an "upgrade" as being imposible. How can you do better than perfect? And if you change most anything there are downsides. There's even less to gain than w syn in an FL engine.

I can't get over the chance that there's something, some quality or feature of this "upgrade" lubricant that isn't as good for the trans as ATF. Not particularly but like seal swelling. New mousetraps may trap the cat. Would you drink "new" Coca-Cola? Why?

Click to expand...

Eric - You paint such relevant pictures!

The upgrade is that motor oil is a better lubricant for bearings than tranny fluid.

I found this thread doing a search for a similar topic. I'll toss my question in the mix and apologize ahead of time for potentially hijacking the thread.

I have a 1999 Mainship 350 with a ZF Transmission. The ZF manual looks like it is recommending ATF. I had a Yanmar tech. do the engine survey. He found ATF in the tranny and then did a double-check with one of his 'go to' engineers for verification. They both concurred that the ATF needed to be removed and SAE 30 (API-CD) or higher be replaced.

API-CD is considered obsolete, so I'm looking at API CH-4; CI-4; or CJ-4 which are all backward compatible.

I was looking for feedback from folks in the know. This is my first inboard. My Mercruiser outdrives took 90 weight gear oil, which was easy as I used Merc.

Should I be following the manual or the techs that surveyed the boat?

Go to the manufacturer...but probably another case of it may just not matter.

psneeld said:

Go to the manufacturer...but probably another case of it may just not matter.

Click to expand...

An example of "... it may just not matter."

Two 71C Borg Warner Velvet Drive transmissions are OEM in our 1977 Tollycraft. They are hooked up to a couple robust 350 cid, 255 hp Mecruiser engines [i.e, marineized Chevy's]. Often run at 3600 rpm. Also often run below 3000. Sometimes below 2000.

a. Starboard one was never rebuilt and after 40 yrs. still performs fine. Port had coolant leak into its fluid and was rebuilt by a pro 13 yrs. ago.

b. 1977 OEM recommended fluid was Ford Type F trany fluid. Guess that was used for first 27 yrs. of these trany's life.

c. When port was rebuilt the pro rebuilder strongly recommended Dextron II or III [can recall the number from back then] in both trany. That is pretty much as it has been ever since. They've had Dextron III in them for years now.

d. Many boat owners with same transmissions use and recommend motor oil as the best fluid.

e. Seems that all of us with the same transmissions from same OEM, built in different years and used in different ways [commercial or pleasure] have really good results with more than one type of fluid inside.

Therefore as psneeld stated: "... it may just not matter."


From what I have learned... one of the biggest things regarding not wearing the trany out is to shift correctly. In other words: Don't shift above 1000 rpm and best to shift in the 600 rpm range. Also, when shifting at any rpm don't slam the trany into forward and then reverse and back again without giving it a count of two to three in neutral position before going into opposite position it previously was in.


That's all I know Boater Folks!


Happy Trans-Fluid Daze - Art

psneeld said:

Go to the manufacturer...but probably another case of it may just not matter.

Click to expand...

They commented on it being a potential heat issue. The Yanmar is rated as a high rpm engine. However, it is only running at cruise from 2200 -2400 rpm's. From reading the thread I'm guessing the SAE 30 would not breaking down as quickly?

I'm wondering if the recommendation is more appropriate for a planing boat like fishing boat (e.g. Tiara) and not as applicable to a trawler.

Shrew said:

API-CD is considered obsolete, so I'm looking at API CH-4; CI-4; or CJ-4 which are all backward compatible.

Click to expand...

These are all updates in time of the same API and should be backward compatible.

L.

Psneeld wrote;
"Originally Posted by psneeld View Post
Go to the manufacturer...but probably another case of it may just not matter."

Just because the trans dosn't go gunnysack dosn't mean it doesn't matter. By that yardstick it could be about to go tits up. I've got an 87 Stanza car w 290000 miles on it. Still go'in down the road and never let me down but it's obviously quite worn out.
Synthetic could be better but I know beyond any shadow of doubt that ATF (Dextron) is proven to be excellent and is recomended as the prefered lubricant by most.

The new Dexron 6 is not allowed to shear down in viscosity as much as Dexron 3. But this may be more of an issue in a higher temp car and truck app versus a boat.
Old much used Dexron 3 gets real thin, it gets shredded into shorter length oil molecules, so it is not as stable as Dexron 6.
My boat does not get enough use to shear Dexron 3 thinner, it always seems about the same viscosity as new even when the fluid is old.
An old thin Dexron 3 might be wearing your trans out quicker than using an old Dexron 6 fluid.

DEXRON-VI
The fluid specification for Dexron-VI was introduced in 2005, and was first used as the GM factory-fill automatic transmission fluid for model year 2006. All Dexron-III licenses expired permanently at the end of 2006, and GM now supports only Dexron-VI fluids for use in their automatic transmissions,[3] although fluids asserted by their manufacturers to meet Dexron-III standards continue to be sold under names such as Dex/Merc. These fluids are not regulated or endorsed by GM.[4]
Dexron VI is of a slightly lower viscosity when new compared to the prior Dexron fluids (a maximum of 6.4 cSt at 100 °C for Dexron VI and 7.5 cSt for Dexron III), but the allowed viscosity loss from shearing of the ATF during use is lower for Dexron VI, resulting in the same lowest allowed final viscosity for both Dexron III and VI (5.5 cSt) in test.[5] In reality most of the DEXRON-III fluids typically sheared to about 4.2 cSt in use. The lower, more stable viscosity improved pumping efficiency within the transmission and fluid stability over life. Since Dexron VI is not allowed to thin out (lower its viscosity) as much as Dexron III during use, it requires the use of higher-quality, more shear-stable (less prone to thinning while in use) formulations.[4] The current GM specification that defines the fluid is GMW16444, which superseded the original specification, GMN10060.

Click to expand...

Nomad Willy said:

Psneeld wrote;
"Originally Posted by psneeld View Post
Go to the manufacturer...but probably another case of it may just not matter."

Just because the trans dosn't go gunnysack dosn't mean it doesn't matter. By that yardstick it could be about to go tits up. I've got an 87 Stanza car w 290000 miles on it. Still go'in down the road and never let me down but it's obviously quite worn out.
Synthetic could be better but I know beyond any shadow of doubt that ATF (Dextron) is proven to be excellent and is recomended as the prefered lubricant by most.

Click to expand...

Pulled my tranny this week for a dampner plate replacement.

Sending the tranny out for seals and a look inside.

I will let you know what the repair facility says about using 30Wt.

I have no doubts after beating up a fleet of trannys filled with 30wt that get a marine beating like Baja dune buggies beat their systems.

I usually only take a stand about this stuff when I have a lot of practical, real life experience with it.

Dex VI is not backward compatible to Dex III.
Full synthetic versions are more shear stable and transmit heat faster than semi or non-syn.