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Discussion Starter #1
New owner of 2005 3500 dually with Allison 1000. manual says
Dexron 3.... am wondering is the Dexron/mecron or the
Dexron/mercon H all good to use?
do know the truck was manufactured 11/2004 so definitely is pre Dexron 6. right? lol Thanks for ur help!
 

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NO. No Dex/Merc, unless you want to replace your trans. Dexron 6 is the replacement for 3.

There are 4 different Mercons and 2 current Dexrons. How could one fluid replace all of them? It cannot.
 

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Transynd from Allison is the correct fluid I believe, Id have to run the vin and double check on monday
 

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I see on Allison site it does say the Transynd or approved TES 295 and TES 468 Fluids(not sure just what those are yet). I have also found that Dex 6 is not recommended for pre-2006 model 1000's as it will harden the output seals and cause leaking over time. I had a trans service about a year ago and pretty sure it was with Dex 3 so now Im wondering if i can't find dex 3 to top off (down about 1/2 qt i believe) is it a problem to start adding a full synthetic type to the Dex 3 that in her now? .....continuing to investigate
 

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I see on Allison site it does say the Transynd or approved TES 295 and TES 468 Fluids(not sure just what those are yet). I have also found that Dex 6 is not recommended for pre-2006 model 1000's as it will harden the output seals and cause leaking over time. I had a trans service about a year ago and pretty sure it was with Dex 3 so now Im wondering if i can't find dex 3 to top off (down about 1/2 qt i believe) is it a problem to start adding a full synthetic type to the Dex 3 that in her now? .....continuing to investigate
Correct. Any TES-295 class synthetic trans fluid. Price varies and Transynd by Castrol, Max ATF by Royal Purple, Valvoline, Delvac, John Deere, Schaeffers, Redline, Triax, UltraSyn, all make TES-295 Allison approved fluids. Stay with TES-295 fluids. Look online John Deere brand is priced nicely.
Also shy away from using anything other than a genuine Allison spin on filter. Some affect line pressure and don’t collect enough debris and flow rates are different. I have used many over the years. Allison filters are consistent and work every time. Of the others Fram spin on behaves similar to the Allison and are closely matched in design.
No additives. Ever.
I’ve used Royal Purple TES-295 for several years in several Duramaxes. Stock and fully built. Never a problem.
The TES-468 is not for the 1000 series.
The Allison also prefers fluid level to be on the lower side of the “hot” hash marks. Don’t forget the internal magnet on the inside of the pan as well as the spin on magnet. The pan is easily serviced and the gasket can be re used. Like the oil pan fluid stays in the bottom during the fluid changes. Unless truck is jacked up high in the front you’ll add old fluid to the new with any sludge or material sitting there. Pan removals are necessary and aid in diagnosis and wear/condition.
Hope this helps.
 

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