jleonard
Guru
- Joined
- Jun 25, 2008
- Messages
- 5,155
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.
That is input rpm as in engine rpm.
That is from BW.
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.
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!
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!
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.
The enemy of good is better.................
The million dollar question in these forums often is...what truly IS better?
Read carefully, my manual...but not all the manuals says 30WT or 40WT is OK if under 3000 engine RPM.However as I recall the manufacturer specs ATF and says engine lube oil is ok under certain circumstances.
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?
Go to the manufacturer...but probably another case of it may just not matter.
Go to the manufacturer...but probably another case of it may just not matter.
API-CD is considered obsolete, so I'm looking at API CH-4; CI-4; or CJ-4 which are all backward compatible.
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.
Pulled my tranny this week for a dampner plate replacement.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.