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Transmission For 1998 AWD Mountaineer


Active Member
March 18, 2010
Reaction score
City, State
Amory, MS
Year, Model & Trim Level
1998 Mountaineer AWD
Can anyone tell me what transmission is used in the1998 Mercury Mountaineer AWD with the 5.0. It's automatic. We've had ours for 22 years and are almost at the 300,000 mile mark and the transmission went out today. The engine is still pretty solid, however. I'm trying to decide if it is worth it to replace or rebuild.

Also, can the regular 2WD automatic transmission be used in its place? I removed the front shafts many years ago so it has essentially been a 2WD ever since. I was just curious if I could swap to a regular 2WD automatic transmission or would other modifications be required.

Thanks in advance!

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Pretty positive >> 4R70W trans with the 4404 AWD transfercase in yours.

Are there different variations of this transmission, or would any one from the same year/similar application work? Of course, I am assuming the transfer case would simply bolt and unbolt from the transmission and connect to another.

Or, could I delete the transfer case altogether and change the driveshaft? Or, is there more involved than that? I am not a transmission guy, by any stretch of the imagination.

The 4R70W trans has 2WD and 4WD versions, the output shaft is different between them, plus the tail housing. You'd have to fully take one apart to change that output shaft, it's the first part installed into the empty case.

You are better off to repair yours, unless you burned it up(drove it after the first symptoms and forced it to go until it completely overheated and quit pulling). Excess heat makes a trans not worth rebuilding, future failures are very common on those.

That said, you should be able to find a reasonable 4R trans, 4WD version, for a 98-01 Explorer, or the 4.2 V6 F150's of similar years. Lot of parts can be mixed, but you'd need a good trans tech to put it together right. The labor to R&R the transmission is typically 75% of the cost of a shop rebuild price. If you could find a local builder and take the trans to them, that could be way cheaper(you doing the R&R).

I would think you could find a low mileage (100K) one from a junk yard. As mentioned 2wd has different length tail shaft and they are not directly interchangeable.