...I've often wondered, other than the valve body, what makes later model trans superior over the 95 and older trans?
Originally Posted by Mgino96tbird46
The later transmissions, 98 and up, have a mechanical diode instead of a one way roller clutch. ...
The 96 and later 4r70w's have better transmission pans. The design of the earlier pans can cause oil starvation on sharp left or right hand turns, I can't remember which direction. I do believe the later pans hold more oil too.
Having one of each (97 and 02) apart, there are changes in the bearings, gasket, fluid passages, valve body circuits, snap rings, accumulators; Lots of changes from the early ones.
These 02 trannys are good upgrades.
We cant use one later than 02 without mods; mods that involve changing the tail shaft, the last part out of the case.
The later you go after that, the more there is to change.
If you want a new stock transmission for a fairly stock MN12, buy a 4R70W out of an '02 Gran Marquis with low mileage.
Gran Marquis' with rear end and side damage are pretty common here...
Crown Vics are OK, as long as non-police; they tend to get pounded on more, tho.
For stock use, there is absolutely nothing you need to do to it, and it will work very well. The TC is better than stock as well.
You need to add the transmission to the tune; there's a value file, as well as the 127.5mph shift thing. (Depending on your tire/speedo gears, 80mph can be 127.5mph unintentionally. 195/35-15 tires will not work, lol.)
My current tune shifts like a manual; TC locked in 2nd and 3rd. Shifting into 4th at wot with the TC locked breaks the tranny's direct clutch, BTW.
Without a tune, the 02 tranny will act strange shifting into 4th at no throttle. It's not a problem, just noticeable.
Search my posts about it; I started here as a complete noob.
At this point, I've changed all 3 cars to 02 trannys, reworked a valvebody successfully, and am rebuilding my first one.
If you want a built tranny, I would call someone; rebuilding one of these yourself is a study in cleanliness, and a mistake is ~$400.
One little thread from a rag will kill it, if it's in the wrong spot.
EDIT: BTW, I'm mixed on the VB
being a total upgrade; they eliminated a plate that is needed, and eliminated a backout circuit that may have contributed to the dimples in my separator plate...