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hzjcm8

Retired Allison Transmission Fluids Engineer

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15 hours ago, Vaughnst said:

Can you use Dexron III ATF synthetic in place of TransSynd

Welcome to the forum. 

Why? 

Have you done a oil analysis to see if it needs to be changed?

More info on your situation would help.

Bill

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JMHO, but it makes no sense to replace Transynd.  It is the best on the market and, if tested regularly, is good for life.  I use J.G. Labs...http://www.jglubricantservices.com/...it is owned by Tom Johnson, who started this thread.  I've used it for several years and get a very detailed report on my oil.  In fact, I just mailed off a sample today.  In the process of filling out the paperwork, I had a question, called the number, and Tom answered the phone.

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On 12/28/2016 at 10:10 PM, Vaughnst said:

Can you use Dexron III ATF synthetic in place of TransSynd

Hi.    I'm back after being away for a long time.    DEXRON-III is not a synthetic and it's also not an oil brand.    DEXRON-III "was" a General Motors specification for automatic transmission fluids and described the testing requirements for fluids to pass in order to be considered for approval by the GM ATF Committee, of which I was a member for around 20 years.    GM DEXRON-III fluid specifications (DEXRON-II, DEXRON-IIE, DEXRON-III, and DEXRON-IIIH) are now obsolete.    These older specifications were replaced by GM DEXRON-VI ("6").    DEXRON-III fluids were mostly based on a mixture of API Group II base oils with good additives packages.    Generally, they were good fluids but tended to lose viscosity (thin out) over time.    Do to some unique requirements, listed in the Allison TES-295 specifcation, the TES-295 approved fluids are formulated with true synthetic (API Group IV) base oils..    Please note that DEXRON-VI fluids are not recommended for Allison products built prior to 2007.   I don't believe they are recommended today either.   Allison recommends TES-295 approved fluids (Castrol TranSynd, BP Autran Syn 295, Shell SPIRAX S6 A295, Mobil DELVAC Synthetic ATF, etc.).    A list of approved TES-295 fluids can be found at  Allison TES-295 Approved Fluids List

Hope this helps !!!     For more about API Base Oil Groups and how they are defined visit API Base Oil Definitions.    Also, refer to the attached chart.

API Base Oils.png

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I would like to butt in to this conversation if you don't mind. I have a 2002 Winnebago with the Allison 3000 transmission. I have used transynd since 2010 when I bought the coach. I just had the filters and fluid changed (after 36 months) and the service place used Dexron. Stupid me I failed to tell them to use synthetic. The transmission now slams into 4th gear as the coach decelerates. Would the change from synthetic to non-synthetic cause that problem?

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gaylejp,

I was asked to comment on this post.    The change from TranSynd to DEXRON-III (probably a modern day "D3M" fluid) would typically not manifest as a harsh shift.   See "D3M" note below.   I don't believe you'd see (or feel) any real difference in what we at GM referred to as "shift feel" under most shifting conditions (upshifts, downshifts, wide open throttle or closed throttle).    I don't know what fluid they installed; but, most would be compatible from a frictional properties standpoint.    TranSynd had a GM DEXRON-III license at one time (way back).    Testing for these type fluids includes frictional testing and the test requirements were basically equal for the Allison TES-295 and GM DEXRON-III specifications.    

My bet is that it's something else may be a contributing factor in the harsh shift.   Maybe they introduced air into the fluid by either under filling or over filling.    Did they use a "flushing machine"?    Or, did they just drain it and refill it?    I'd check the fluid level using the dipstick and the onboard electronic shift selector method.    Make sure the fluid is in the "COLD" band when cold with vehicle on a flat surface, transmission in "P" and engine at idle.    Once it's warmed up, it should be in the "HOT" band under the same conditions.    Please let me know what you find out.    See what they put in it and let us all know !!!    

NOTE:   Manufacturers can no longer use the word "DEXRON" on their packaging since the DEXRON-III specification is obsolete.   So, instead, they call the fluids "D3M" which indicates that the formulation, at one time, passed both the GM DEXRON-IIIH specification and the Ford "MERCON" specification.    Most of those older DEXRON fluids passed both specs.   Thus, "D3M" means DEXRON-IIIH/MERCON.

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I always have my coach serviced at Cummins in Houston, every year around now.  I don't have to worry about the correct fluids for the engine, generator or Allison.  Yea, there are cheaper places, but at least I know who to fall back on!  Always felt, you get what you pay for, if it's a known, reputable place to begin with.  I'm to old and brittle to do it myself.

Thank you, Mr. Johnson, for your time and expertise.

Carl

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Thank you for the detailed explanation.

I often see in my line of work a "universal" automatic transmission fluid that is trying to be pushed upon us and marketed as it can go in anything. In my opinion there  is not "one size fits all" in the category. Especially if you have a newer Ford product calling for Mercon SP or LV. Most will advertise their fluid is compatible or the person selling assumes.  If you have ever encountered that Ford spec there is no mistaking it (smells like gear oil friction modifier) and it has a heavier viscosity that you can see.

I would find out what fluid was actually put in and take it from there. If it was the incorrect fluid take it back. 

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My motor coach hydraulic system calls for Dexron III. The hydraulic system runs both the power steering and the side radiator fan. I want to drain out four gallons of the old Dexron III and replace the filters. Can I mix 4 gallons of Dexron VI with the remaining 7 gallons of Dexron III that will still be in the system? I read somewhere that Dexron VI is not compatible with Viton seals. I don't know if the hydraulic system has any Viton seals or not, but I don't want to cause any damage. Or, I have several gallons of BP Autran Sun 295. Would it be better to mix that with the old Dexron III?  Confused.

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Calvin9853,

My recommendation is to stick with the BP Autran Syn295 fluid.   Do not use DEXRON-VI.    If the seals in your hydraulic and power steering system are made from a certain type of Viton (fluoroelastomer) known in the industry as "non-base resistant", then, they may not be compatible with DEXRON-VI and may harden and crack over time.   No one in this universe would be able to tell you the exact seal compound in your seals in the hydraulic or power steering systems.   So, it's best to stick with the BP Autran Syn295 product.    Back when GM was still licensing DEXRON-III products, the BP Autran Syn295 fluid would have passed the DEXRON-III specification and would have gotten licensed.    That's all history now; but, you can trust what I'm telling you.    The BP Autran Syn295 fluid is "very" compatible with the seals in your hydraulic and power steering systems.  

 

PS:    Note to forum members.   Please do not go nuts with a multitude of questions about seals and fluids.   Trust me on this.    If your system, be it RV, automobile, truck, equipment, etc., calls for a DEXRON-VI approved fluid, then use a DEXRON-VI approved fluid.    If, on the other hand, your Owner's Manual calls for a DEXRON-III approved fluid (which would be the case for most systems manufactured prior to 2006), then you're best off using one of the Allison TES-295 approved synthetic fluids because the Allison spec includes the Viton seals test.     I say this because GM no longer approves DEXRON-III products and most on the market today are unlicensed products.    Most will say "D3M" or something similar since they can't legally use the DEXRON trademark.

HOPE THIS HELPS !!!

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Thank you! Just to clarify.  If I understand you correctly. I can mix the BP Autran (4 gallons) with the residual Dexron III ( 7 gallons ) that will still be in the system after I drain the  4 gallons from the Hydraulic Reservoir and change filters. . There is no problem mixing the old Dextron III with the new BP Autran Sun 295?  Thanks

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Oddly a friend (who bought my old 2004 Itasca Meridian) with a Cat C7 and a mh3000 transmission used his shift pad to find his trans fluid level to read 7 quarts low. (Dip stick looked right).   After adding 4 quarts and continuing on his way to his camp ground it now reads 8 quarts low. 

The trans shows no sign of leaks. Drives and shifts great.  - in fact he said it shifted a little smoother after adding the fluid. 

Can anyone share what symptoms you would see / feel from over filling?   It has run well for the last 5k miles - 

It just doesn't add up that the shift pad has provided such different readings.  Is there a calibration required?

 

Thanks!

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  I have a 2003 diesel pusher with ISM engine and 4060 Allison.  It has always had transynd in it from day one.  Last transynd  fluid change was 2011. The transynd was tested fluid tested in 2015, and the filters changed at the same time (2015).   Now has 102,000 miles total on the rig. 
 

Is there any reason to change the fluid again?  Or is it pretty much life long at this time? 


 

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20 hours ago, AC7880 said:

  I have a 2003 diesel pusher with ISM engine and 4060 Allison.  It has always had transynd in it from day one.  Last transynd  fluid change was 2011. The transynd was tested fluid tested in 2015, and the filters changed at the same time (2015).   Now has 102,000 miles total on the rig. 
 

Is there any reason to change the fluid again?  Or is it pretty much life long at this time? 


 

Have the fluid tested and you'll have your answer, I have mine tested annually.

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Hello Tom,

I am James Shadrock.  I'm inquiring on a 2007 Newmar Kountry Star Motorhome with a 350 cummins engine with automatic transmission.   Is the trans cooler in the radiator or the separator?  We have water in the transmission.  I think the transmission is a 3060.   

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James,

Welcome to the FMCA Forum.

I am not Tom, but your chassis maker is the one who designed and installed your cooling package and can tell you exactly how your transmission cooler is plumbed. 

Yes, most are in the radiator. 

But calling your chassis maker with your VIN will tell you for sure.

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What some refer to as a transmission fluid cooler in the radiator is a misnomer IMO. How much cooling effect will occur from 195° engine coolant? It is actually a transmission fluid heater IMO. My Allison temp gauge run 180-190° during normal driving conditions, when climbing mountain it may reach 205°-210°. Very little cooling will occur under those conditions.

I've never seen an Allison automatic transmission without a separate  oil cooler, even my old Chevy Duramax W/Allison AT had an OEM external oil cooler.

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 RayIN,

A valid point.

They are actually transmission temperature "regulators".  On cold start up and in extreme cold conditions, they HEAT the transmission so it  more quickly reaches proper operating temperature range.

But, it also cools the fluid, particularly if in stop and go traffic where the torque converter is slipping and creating a lot of heat in the transmission.  Under these conditions, transmission fluid temperatures can exceed 250 degrees F. Running it across 180-190 degree coolant does cool it down.

 

BTW, same for engine oil coolers like your Cummins C engine has.  Again, engine coolant is used to cool (yes, and heat) engine oil.

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Welcome!

I had the 2007 Silverado 2500, 4x4, Duramax engine/Allison & manual said the same!  I used it as a toad.

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