Thank you all. The are a couple of reasons why I'm wanting to change the fluid now is because I have a receipt for this transmission but, not sure of the fluid they used other than I think the receipt says synthetic but, not certain. Changing the fluid now allows me to start on what I know I'm putting in and the filter being used. The other reason is to inspect to make sure there is nothing wrong with the transmission and just take a look at things. I bought the vehicle in this configuration and the prior owner had a shop do the work. I just want to be able to know and start something so I continue using the same stuff on a basis in the future when needed. The reason why I was asking about the fluid is I know ATF+4 is more slippery but, I read somewhere it also hold ups better to heat and the this vehicle has headers close by the transmission along with the exhaust setup so I wanted to confirm my thoughts on that.
Not sure of your concern about ATF + 4 being slippery.
All the transmissions used it starting around 2000 model year at Chrysler. Even the HD diesel transmissions.
The 48RE “works” the same as the 727, unmodulated clutch apply. If it will live in that environment it will live in a race car too.
ATF + 4 has proven to improve geartrain durability too, and compared to the Dexron fluids geartrain durability was improved 4 fold.
In a Chrysler 4 speed the overdrive especially.
