by Philip » Mon Mar 17, 2008 8:40 am
The fluids will interchange.
The ATF4 just has some different additives.
The MFG's and the oil industry have to keep the fluids where they can interchange with the wide range of year models of transmissions on the road today. Out west there are still cars on the road that use ATF 1&2 which you can't even find anymore.
The higher number ATF fluids seem to be just a little thinner from the previous number. This will change the way a trans shifts. Most of the time the shifts will be a little firmer and faster.
You can even use Ford ATF in a Dodge trans. It is a ligher fluid and the shifts will be faster. The stall range will go up just a little on the converter. On a lightly built gasser the stall normally goes up around 150 RPM or so with the Ford fluid. If your running in a limited class on a drag strip. That extra 150 RPM helps on the launch.
93 W350 Club/cab w/duals, buckets & console, B&W flatbed, G56, 6 spd, 3:07 rears, gages, HX40/16, 4" exhaust, 6X.018 sticks, rear air ride suspension