4.0 to newer 4.0

[Denisefwd93]

I'm getting a 98 4.0 and M50D for my 93.

Going to store the newer 4.0 but would like to slowly prep it for the eventual install into my 93. I think the harness on the newer engine will be gone or badly ripped up. Should I track down another 4.0 harness from a early 90s and save time when we do the change over?

Other then switching the older harness onto the newer, what other things will need to be done? Like the intake? it's very different on the 98

Hows about the Alternator, Power steering and AC and exhaust?

 

[RonD]

Best thing would be to stay with your current '93 EEC-IV(OBDI) computer and wiring harness, in '95 Rangers got EEC-V(OBDII) computer and harness.

Swap upper intake from '93 to '98, also remove CPS/syncronizer from '98 and replace it with oil pump gear and plug from '93, unless your '93 has CPS/syncronizer(some did some didn't).

Accessories(Alternator, P/S, AC) should be the same, but you may want to swap '98 brackets and accessories for '93 so when you go to replace belt or parts it will be for '93.
The less "Frankenstein-ing" you do the easier it will be to get the correct parts the first time around down the road
You can use the newer parts, just in the '93 brackets

There were some changes in the engine from '93 to '98, most notable were changes in the crank, '93 will have 6 bolts for flywheel, '98 8 bolts, also nose end was changed.

Read here for the 4.0l OHV changes: http://www.therangerstation.com/tech_library/40rebuild.shtml

This can matter when changing main seals and oil pan gaskets

 

[Denisefwd93]

Cool Ron, thanks! I really feel lucky to have found this part out so close to home! and with 62,000 on the OD It's like a God send! LOL Needless to say I'm getting impatient to make this project happen, but it's the small parts that will bog it down. Still not found the clutch pedal assembly.

 

[RonD]

62k is barely broke in for the 4.0l OHV, good find

I would change front and read main seals, they are cheap, new oil pan gasket as well since these are all hard to do with engine in vehicle, but at 62k these might be just fine, your money so your call as always

 

[Denisefwd93]

Oh yes they will definitely be replaced on that engine too. My existing engine has a 133,000 They're both leaking. Put some snake oil in it, and the drips actually slowed down.

 

[RonD]

Lucas oil additive helps swell the "rubber" on valve guide seals and main seals, it does work.

 

[Denisefwd93]

Lucas oil additive helps swell the "rubber" on valve guide seals and main seals, it does work.

I stopped using 5w30 synthetic too