[Huskymaniac]

Originally Posted by NiftySVX

Messing with the transmission is a tricky business. Adding a cooler that restricts the flow will do more damage than good, and the fluid temperature isn't really an issue with these. A filter is not needed unless it is a 92 with the old torque converter, and really all of the 92s need to have their radiator replaced and converter replaced. A filter is just another possible flow restriction in the cooler circuit. The phase 1 4EAT suffers mainly from issues stemming from weak line pressure. The high clutch has a tendency to burn up, but this isn't because the fluid is hot. It slips and then superheats the fluid so the hot fluid is a symptom not the cause. Cooling fluid exiting from a burnt up clutch pack isn't going to help anything.

Disconnecting the resistor can, in some cases, allow a trans that is on its way out to last just a bit longer. But other than that, you're just going to have line pressure that is too high when at idle resulting in hard shifts.

The only real way to modify the transmission for "longer life" is to make changes to the valve body to boost main line across the board and bore out certain passages to MAKE SURE the high clutch has alot of pressure when it is applied and to make sure that fluid is draining from it when it is not applied so that it is not dragging. This is the prevailing theory, at least.

It should be noted that Subaru gave up on the design of the original 4eat and started over.

I hear what you are saying about the cooler. My mechanic is also hesitant to add one for much of the same logic you put forth here. But I have one add-on question. If you cool the fluid then it starts colder when it enters the high clutch so it should oxidize less since the terminal temperature when the fluid leaves the tranny should be a little lower since it started out lower before it got heated up by that clutch.

So I see that you put a new valve body as the #1 mod for extending the tranny life. Hard to argue with that. What would be your #2 mod from the list I gave? And which of the items actually don't help or hurt?