welcome to trs
you are staying with 2wd correct?
In 1985 and up the computer runs the automatic transmissions(full control in 1995 and up), and it is part of the computers firmware.
If you go with a manual trans then v8 computer will not idle engine correctly and will turn on the cel(check engine light) and it will stay on, because it "thinks" there is a problem with the automatic since it is not connected to one, lol.
1998 explorer should still have the 4r70w 4-speed auto.
And that's what the 1998 computer will expect and can control.
You will need a 2wd 4r70w, the 4wd 4r70w can't be converted to 2wd.
Maybe do some trading, 4r70w w/transfer case for 2wd 4r70w
and you need the column shifter for the ranger or custom floor shifter for automatic
but pause here.
1998 explorer has pats(passive anti-theft system), it will have a pats module above glove box connected to ignition key slot and the computer.
Pats keys have an rfid(radio freq. Id) tag embedded in their handle, it requires no batteries.
When you insert the pats key and turn it on the pats module sends out an rf burst from the transceiver(loop antenna) at the key slot, that gives the rfid tag enough power to respond with it's unique tag id number.
Pats module gets that number and compares it to a list in has in memory, up to 8 key numbers, if the number matches one of these then pats module sends "ok" to computer and computer starts fuel pump and fuel injectors.
If it doesn't match or computer doesn't get the "ok" then engine just cranks and won't start.
No alarms or parking lights flashing, just no start, "passive" anti-theft.
Pats module and computer are "married" at the factory, and 3 or 4 pats keys are added to pats memory for use by new owner.
The "marrying" means pats module and computer have a special "code" that changes all the time, so it isn't possible to fake the "ok" message.
Ford dealers can replace computer or pats module and then "remarry" the new part to the old, it requires an active subscription to fords database, which only dealers can get, and it can only be done "in the vehicle", so you can't just drop off pats module and computer to get "married", have to install it then have vehicle towed to dealer.
Most locksmiths(and all ford dealers) can add new pats keys to the pats module.
And if you have 2 working pats keys for a vehicle you can add new pats keys yourself, after they are cut for the ignition switch.
So..............decision time
to use 1998 computer means switching over 1996 ranger to pats and getting a 4r70w 2wd automatic.
You have complete system in donor vehicle so all parts are there, you would have to change ignition key cylinder, but..........
You can just hook up the transceiver(antenna loop) to the pats module and place pats key next to it, so each time ranger key is turned on pats gets correct number from explorer pats key, this can just be under the dash out of sight, just taped together, but easy access, just in case of a problem.
Or find a 1996/1997 explorer v8 computer, they don't have pats, 1998 was first year, and use 4r70w 2wd trans, if new computer was from an auto.
Or find a ford computer programmer that can delete the pats on 1998 computer and he can also set up computer for 4r70w or manual trans.
No, i don't know how much that costs.
Best manual trans would be 1997 and up m5od-r2 from f-150 2wd with 4.2l v6, 4.2l v6 and 5.0l v8 have same trans bolt pattern, in 1997 the m5od-r2 trans had the shifter moved farther back so matches up very close to ranger m5od-r1 placement
also look here for ranger v8 swap info:
http://www.therangerstation.com/tech_library/index-conversions.shtml
lots of "been there done that" info there from members here
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