Hey all, The title pretty much covers it. The shop said we could use Dexron III if desired. Easier to find and cheaper. They did say the type F would shift firmer and is often preferred. Mild shift kit, etc. Unfortunately my son is leaning towards selling, I’m hoping the rebuilt transmission causes him to rethink it. Chris
The friction coefficient is different for F, gives somewhat firmer shifts. Back in day, GM guys often used it in Turbo 350 & 400. Then B&M copied the properties and sold it as Trick Shift. Some years back I used F in a slipping '93 Grand Marquis AOD. Along with a B&M electronic shift improver got another 98K mile out of that transmission(died at 131K from a blown pump to case gasket). Also I had a slippy A4LD in a Aerostar, with F was still shifting OK at over 150K miles. Most A4LD were dead by 90- 110K mi. F should be changed at approx 25K mi intervals.
Yep back in the day F was the stuff. For max performance race now, we exclusively use Tractor Supply's Traveller Premium Universal Tran/Hydraulic Fluid. Great stuff, holds up to high temperatures extremely well and extends the life between rebuilds. Shifts very firm and it's only like $40 for a five gallon bucket.
On your recommendation I’m going to buy a bucket of TSC’s hydraulic fluid and give it a shot in everything I’ve previously used automatic transmission fluid in (eg snow plow pump, transfer case, and manual transmission’s).
I don't have any idea where to find the information now, but years ago I read about the difference between Type F and Dexron. Evidently Type F was designed to slip less as clutch pressure, helping the clutches lock up. Dexron was made to become more slippery under pressure, giving smoother shifts.
I think it also has something to do with the ...clutch material...being different in the newer rebuilt transmissions
I drag raced a '88 T-Bird with stock(does have shift kit) AOD for 10 seasons, used F with no issue. Finally blew the 5.0, transmission is still fine.
