Before the raging firestorm ensues, I know +4 is not the spec fluid for this trans and won't yield any major benefits besides enhanced longevity and more consistent performance. Now, carrying on:
Does anyone have prior experience using Mopar ATF+4 in a GM trans that originally spec'd Dex-III? I have a bunch of it on hand and would like to take advantage of its more-consistent performance and longer service life compared to Dex-III. I would be using it in a 2000 model 4T60-E with 180k miles on it. It has had the fluid and filter changed at least once around 100k, so it shouldn't be on the verge of complete death. I'm unsure if it's been done more than that.
After studying Chrysler's SAE paper 982674 my gut reaction is that it would be fine. Both fluids are nearly identical in terms of cold and hot viscosity, and perform very similarly in service (until the Dex begins to degrade). Backing that feeling up, Chrysler superseded many of their Dexron-II factory-filled units' fluid with the ATF+ series. In the early days of the A-604 they also claimed ATF+ and Dex-III were interchangable (though we all know how that turned out in the Chrysler transmissions).
"If you want a good synthetic fluid, why not use Dex-VI? GM said it's ok for your application." - I would, but I have a ton of +4 lying around.
Thoughts? Feelings? Objections? All much appreciated
Does anyone have prior experience using Mopar ATF+4 in a GM trans that originally spec'd Dex-III? I have a bunch of it on hand and would like to take advantage of its more-consistent performance and longer service life compared to Dex-III. I would be using it in a 2000 model 4T60-E with 180k miles on it. It has had the fluid and filter changed at least once around 100k, so it shouldn't be on the verge of complete death. I'm unsure if it's been done more than that.
After studying Chrysler's SAE paper 982674 my gut reaction is that it would be fine. Both fluids are nearly identical in terms of cold and hot viscosity, and perform very similarly in service (until the Dex begins to degrade). Backing that feeling up, Chrysler superseded many of their Dexron-II factory-filled units' fluid with the ATF+ series. In the early days of the A-604 they also claimed ATF+ and Dex-III were interchangable (though we all know how that turned out in the Chrysler transmissions).
"If you want a good synthetic fluid, why not use Dex-VI? GM said it's ok for your application." - I would, but I have a ton of +4 lying around.
Thoughts? Feelings? Objections? All much appreciated