Is Dexron compatible with Allison/Castrol Transynd

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The head mechanical inspector came by our shop today to inspect our equipment. Inspector said that my truck was several quarts low on a/t fluid. My supervisor was in the room and asked what fluid the transmission takes. I replied, Allison/Castrol Transynd.

The mechanical inspector replied, its in the service book in the truck. Sure enough someone took it upon themself to handprint DEXRON III. I know for a fact since 2007 that Allison has been putting Allison/Castrol Transynd in their transmissions. Just goes to show noone where I work ever looks at actual factory manuals.


My question is will putting the Dexron in the tranny harm it in anyway? The damage if any has already been done because my coworker took the advice of one of the so called mechanics and and put Dexron/Mercon in the tranny. I know the older Allisons it was perfectly alright to put Dexron in. But, this is a 2009 Allison 3000 RTD 6-speed automatic. Any help would be appreciated.

Rob
 
Isnt transynd backwards-compatible one way, like it can be used in place of dexron?
 
I don't know about backwards compatible. From what I can gather using Dexron it will just shorten the time between filter and fluid change times. The Transynd is formulated for a much longer change interval. Just glad the blame for the truck being several quarts short fell on the coworker who drives our truck 99.9% of the time. He is not the brightest guy and has no skill whatsoever at driving a large truck.
 
Originally Posted By: Rob Taggs
The head mechanical inspector came by our shop today to inspect our equipment. Inspector said that my truck was several quarts low on a/t fluid. My supervisor was in the room and asked what fluid the transmission takes. I replied, Allison/Castrol Transynd.

The mechanical inspector replied, its in the service book in the truck. Sure enough someone took it upon themself to handprint DEXRON III. I know for a fact since 2007 that Allison has been putting Allison/Castrol Transynd in their transmissions. Just goes to show noone where I work ever looks at actual factory manuals.


My question is will putting the Dexron in the tranny harm it in anyway? The damage if any has already been done because my coworker took the advice of one of the so called mechanics and and put Dexron/Mercon in the tranny. I know the older Allisons it was perfectly alright to put Dexron in. But, this is a 2009 Allison 3000 RTD 6-speed automatic. Any help would be appreciated.

Rob

I'd stick with the TranSynd/Delvac ATF in the Allison. And it's child's play to check fluid on the push-button shift Allisons, I showed a bus driver how by pressing the UP and DOWN arrows at the same time. The LCD will blink out oL oK if the fluid level's fine. If it's low, it will blink out oL Lo ox where x=number of quarts low. Not that I've have any experience with heavy-duty trannies or big rigs/buses.
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You are not being specific enough.

Dexron is simply a brand name for a range of products from GM (former fluids were Dexron, Dexron II, III, etc. and the current tranny fluid from GM is Dexron VI). Ford has the same thing with "Mercon". Mercon, Mercon V, Mercon LV, Mercon SP, etc. It is important to know that GM no longer licenses "Dexron III" and Ford no longer licenses "Mercon"; that is why you see "D3/M" or "Dex/Merc" or some other variation of those terms. Because they are no longer licensed, those full product names cannot be used. But the aftermarket offers many viable fluids that mimic those old standards. You would be safe as long as you choose from a reputable large name brand. However, I will acknowledge and state that once licensing has ceased, there is no garauntee of performance any longer; you are relying on the good intent of the lube manufacturer at that point, rather then the intent of the OEM specs.

Further, TES-295 fluids like Transynd are actually constructed to work in the same environment as the former Dexron III and Mercon places. TES-295 fluids are merely the pinnical of what would essentially be DEX/Merc fluids. So, simply topping off with a DEX/Merc fluid is not going to be a catastrophic event in your case. It is merely akin to using a standard dino fluid when topping off any other sump full of PAO based product spec'd for the same use.

You need to be much more specific about your fluids that you are referring to, so we can give you specific answers.

A little background. Allison stood alone, then they were bought by GM, then sold. So, there is a long, mixed history about what is "approved" and what was "approved".

Regarding your specific tranny, I suspect that the factory fill from Allison was indeed a TES-295 fluid (likely Transynd by Castrol). But there are other approved, licensed fluids that meet that spec. That spec is a very demanding performance based spec that can basically only be met with good additive packages and PAO basestocks. You can find a list of licensed fluids on Allison's site.

Allison also created a new fluid spec (called TES-389) that licenses non-synthetic fluids that have appropriately compatible chemistry packages. Of note, you will see that Mobil's ATF meets that spec and is licensed. You can see those licensed fluids on the Allison website as well.

Please note, TES-295 fluids are not "required" by Allison unless you are under an Allison brand extended severe service warranty contract. If you are, you MUST use TES-295 licensed fluids. If not, you can use any other allison approved fluids meeting the specs for your specific tranny. Once out of warranty, there are some really good TES-295 clones from Amsoil, Schaeffers and DA Lubricants that mimic the performance of TES-295 fluids at a far better price.
 
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Originally Posted By: Rob Taggs
From what I can gather using Dexron it will just shorten the time between filter and fluid change times. The Transynd is formulated for a much longer change interval.
we have three allisons at work that take transynd tes-295. in all three manuals it states you can use tes-295(transynd) or tes-389 (dexron III). like stated above if you use dexron III the service interval is severely shortened. the manual also states you can also use dexron vI but it can only be used after a certain serial# in 2008 due to seal compatibility issues. the service interval for dex vI was severely shortened also.
by the way the three transmissions we have that use transynd are one 4000 and two 2000's. not to mention all the other allisons we have that use only the old tes-389 spec (ht-740's,4000,s and one 2000). mike
 
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Originally Posted By: JHZR2
Isnt transynd backwards-compatible one way, like it can be used in place of dexron?


TranSynd failed to meet the DEXRON requirements at the time of the DEXRON-IIIG to DEXRON-IIIH upgrade.

At the time of the DEXRON-VI introduction things became even more embarassing for the TranSynd product since the DEXRON-VI products demonstrated themselves to be superior in most respects and also a much lower cost.

With regards to the so called 'seal problem' in Allison transmissions, what that actually proved to be was a poor choice of seal material which nobody had noticed until they started to evaluate the DEXRON-VI fluid. The outcome was that it was much easier to blame the transition to DEXRON-VI for seal issues than it was to admit that the material selection was probably not the best in the first place.

To answer your original question, is DEXRON-VI backwards compatible and the answer is yes, as outlined in the original release from GM in 2005 where it stated that DEXRON-VI is backwards compatible with all GM Hydramatic transmissions.

Many people have expressed concern at the "low viscosity" of DEXRON-VI fluid, however if you take a look at the viscosity profile of a DEXRON-III fluid you will find that they shear very rapidly from about KV/100'C 7.5 cSt to about 4.1 cSt after 80,000 miles or thereabouts. It should be noted that although DEXRON-VI fluids start off at a lower viscosity KV/100'C, it remains more stable under normal circumstances, contamination aside, it is very rare to see one shear below about 5.3 cSt.

I hope that helps.
 
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