We have a lot of threads/posts on engine oil and filters, but I don't believe I've seen one on automatic transmission fluid(ATF). What is everyone using? Does the model of transmission matter? SP or not? How often do you change it? Any brands you would never use? Any impact on stall? Synthetic or conventional or blend? Racing: Street: High power:
I went round and round and finally made my decision to use ... Valvoline Multi-Vehicle (ATF) Full Synthetic Automatic Transmission Fluid https://www.amazon.com/gp/product/B007VWRUQC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 This is for my newly rebuilt TH400 with a TSP 2500/3000 stall converter. That being stated, I have not started the motor yet, so who knows how it will work out long term.
I have used synthetic fluid in all my transmissions. Dexron 6. I use Valvoline Max Life. Used it in the Switch Pitch, and in my current fixed pitch 400. I also use it in my 98 Riviera, and that has 203,000 on the original 4T65HD.
Switch pitch or not, does not matter, as the only difference with the two is the stators change pitch, all clutches, servos, accumulators and such operate the same. The correct fluid would be the same for both. I used Castrol Dex/Merc (mineral) and I am now using ATI Super F synthetic (Allison clutches) after rebuild. (Converter failure, damaged in shipping. Found out the hard way...)
My trans shop said don't put that B&M crap in there I used Dextron with Mercon in this trans he did for me. I am sure things have changed now I have used the Ford type F also was recommended by same shop years ago with my 350 trans. I never tried the synthetic in the trans I went with what the trans builder told me to use at rebuild time or changed fluid. Synthetic may change how clutches engage and such I don't have much research on that. I do know it did change how the trans or clutches worked on a small 125 dirt bike we had a long time ago. I think it did something to the shifting and I think this was a oil and not trans fluid I do know synthetic worked real good in my 6 speed Toyota made it a lot easier to shift when very cold out Plus you could now row the daylights out of it just like Grumpy Jenkins. ye ha lol
From Pro Built Automatics: "B&M Trick Shift is nothing more than modified Type "F" transmission fluid. I have talked to Borg Warner, Raybestos, and others who work with the many types of transmission fluids, and who can test for holding power and how the clutches will hold up. The results were the type "F" has better static holding power (Park or Neutral to Drive), but the dynamic shifts (1-2,2-3,3-4) the fluid has about 14-19% less holding power than the Dexron 3." https://probuiltautomatics.com/
I use Castrol Dex/Merc in my TH 400 (64 Wildcat). 122k miles and going strong. I've used that in other Ford and GM cars through the years. I use Valvoline ATF+4 in our 2016 Town and Country. 58k miles. I did the first fluid and filter change at 30k miles and will continue that interval. Hey, it's a Chrysler product