using Dex/Merc lll in 06' 48RE auto

[Trophy Truck]

I am in the middle of changing my trans filter and fluid and have adjusted the bands... A source tells me that they recommend Dex/Merc lll in the 06' automatic 48RE transmissions. Has anyone tried this, I understand it firms up the shifts. AND what is the service fill? It looks like 4 quarts.



Thanks!!

 

[JLandry]

A source tells me that they recommend Dex/Merc lll in the 06' automatic 48RE transmissions.

Both the owner's manual and the Dodge factory service manual specifies ATF+4.



The service manual specifically states:

"Dexron II fluid IS NOT recommended. Clutch chatter can result from the use of improper fluid. "​

and

"DaimlerChrysler strongly recommends against the addition of any fluids to the transmission, other than those automatic transmission fluids listed above. Exceptions to this policy are the use of special dyes to aid in detecting fluid leaks.



Various “special” additives and supplements exist that claim to improve shift feel and/or quality. These additives and others also claim to improve converter clutch operation and inhibit overheating, oxidation, varnish, and sludge. These claims have not been supported to the satisfaction of DaimlerChrysler and these additives must not be used. The use of transmission “sealers” should also be avoided, since they may adversely affect the integrity of transmission seals. "​

 

[TimothyLong]

What JLandry said!! The ATF+4 synthetic is supposed to have heat dissipating properties for higher pressures that Dex/Merc III doesn't have. In addition, keep in mind ATF+4 is also used in the power steering pump and NOT regular power steering fluid.

 

[cerberusiam]

Dexron III is most specifically NOT designed for the 48RE. Using it will quite probably cause issues and definitely void any warranty if Dodge finds it.



ATF+4 is one the best engineered highest quailty fluids on the market and made specifically for the HD transmissions and use.



What IS this fascination with using inferior and outdated fluids in these transmissions???

 

[Trophy Truck]

Thanks Gentleman, I wanted to hear from you guys... a source tells me that many people are using the Dex/merc lll because it aids in the TC anti slip process with no reported side effects. But I will probably use ATF+4 fluid. Thanks again, I appreciate the comments!

Dexron III is most specifically NOT designed for the 48RE. Using it will quite probably cause issues and definitely void any warranty if Dodge finds it.



ATF+4 is one the best engineered highest quailty fluids on the market and made specifically for the HD transmissions and use.



What IS this fascination with using inferior and outdated fluids in these transmissions???

 

[cerberusiam]

The latest is Dex VI that would be close to the same type of fluid as ATF+4. III is old technology, doesn't take the heat as well, etc. It probably will help with the slip at the expense of the rest of the trans. If the clutches aren't holding a shift kit is MUCH better investment than non compliant fluid.

 

[Tinman]

Dex III is what I run in both my trans as recommended by my DTT installer. I used +3 in the 47 (as instructed) and then switched to Dex III when +3 wasn't availble. My installer (Chip's trans in TN) said +4 was too slick It may be a bad idea to do this in a stocker, but I haven't used +4 since my rebuid in either.

 

[JJPage]

I have been using Dextron III in my DTT trans since they built it in 04, it's what they recommend. I would not use it in the stock 48RE, or if I was concerned with warranty.