Amsoil 75w90 good for late model Gen2 transmissions?

[efnfast]

Is Amsoil 75w90 manual transmission/transaxle gear oil a good choice for a late-model (2001+) gen2 t56 transmission (with the syntorque sticker on it).

It says GL-4 and Chrysler MS-9070; where I'm getting confused is there are some posts suggesting that Tremec at one point said to just run Dexron III ATF in any T56 as gear oil may or may not work with carbon fiber blockers (which I think applies to the late-model transmission ..... but this is GL4 manual transmission/transaxle gear oil, not GL5 severe gear oil for differentials, so maybe the Tremec posts were in reference to GL5 oil). The factory spec is the Mopar 75W85 transmission & gear oil, which I'm pretty sure the Amsoil is basically the same as.

There are numerous positive posts about the Amsoil feeling like an improvement over the Mopar fluid, but most comments seem to come from pre-2000 and I think something changed in the transmission post-2000, so it gets a bit confusing....

 

[Steve-Indy]

A GL-4 is OK...just don't use a GL-5 in the T-56 tyranny.

Here are a couple of scattered historical FACTS:

Our 1995 Viper came with Dexron II e label

Our 1997 Viper came with Dexton III label

Our 1999, 2001, 2003 Vipers came with Castrol Syntorque labels

2008-2010 and 2013-2017 Vipers came with T6060 transmissions and use ATF+4

 

[efnfast]

I think I spent 5 or 6 hours reading every thread about T56s and transmission fluid at this point, lol

I started getting frustrated when people talked about mixing ATF and two different types of gear oils so I just threw in the Amsoil GL4 75w90 transmission fluid and took it for a drive - felt really good, way better than the 25yr old fluid.

btw, I discovered I <3 the Amsoil squeezie bag. Usually when doing transmissions and differentials i get out the fluid pump and pump it out of the bottle ... and usually have the hose pop out and spill it everywhere and usually make a mess .... their "new" squeezie bag is a huge step up from the pumping method

 

[maverickagm]

I feel like I read every post today trying to decide on fluid for my 1993 t56. The service manual calls for dexron IIe. My understanding is that a non-synthetic dexron III is required because of the paper-lined blocker rings in early t56 units. So in the case of a T56, dexron VI isn't backwards compatible since it's always synthetic.

I ordered Red Line D4 ATF. Their site specifically calls out use on. a T56:
"Also used with manual transmissions and transaxles like T-5, T-45, T-56 and late-model BMW, provides a GL-4 level of gear protection". It hasn't arrived yet, but I'll post back if it causes me any problems.