Any Jeep guys out there?

[hondaxr650]

I have a jeep question. Does anybody know of any differences between a Jeep 4.0 amnual trans. engine and an auto trans. engine?
One of my buddies here at work is doing a favor for a friend and is working on a 99 Cherokee that ended up having a badly cracked head. Instead of paying $700 for a new head they decided to go the used engine route. It has an auto trans. but the used engine they sent him is from a manual trans. vehicle.
Is there any weird differences between the two that he should be aware of before he pulls the old engine and tries to swap it in?
Any help would be appreciated. Thanks.

 

[martin]

physically there should not be a problem. There have been some changes in the electronic controls over the years but if the motor is from a similar year you should not have a problem.

 

[06RangerXLT]

same engine, just have to swap over the flywheel from the old one to the new one so you can mount up your torque converter and bolt it in.

any Q's let me know.

you could always do the easy work and take the head from the used engine and put it on yours... but thats not as fun as pulling a straight 6.

 

[Hahnsb2]

Crank sensor is probably different between the two.

 

[4.0B2]

yeah different years of 4.0 for jeeps get REAL screwy when swapping them out.. it will/can work, but A LOT of work for some swaps.

the motor mounts on some are different, the flywheels/flex plate, the crank senor, the coil vs distributor system, and so on.. i can't think of all of them.. it depends on the years being swapped between. i know on the vet jeep rebuild, we ended up doing a different motor than the first one b/c of the differences

 

[hondaxr650]

Thanks for the responses guys. His biggest concern was the rear of the crankshaft being different, although I seriously doubt it. It seemed to me that they would all be the same and he'd just have to yank the pilot bearing out to mount it to the auto, but I don't know squat about Jeep engines. The engine is the same year as the truck, so I'm guesssing most everything will be the same. He'll probably swap all of the external accessories from the old motor anyway, since he knows they are good. Thanks again!

 

[06RangerXLT]

no problem!

 

[RatDog8o8]

sorry, i have no idea about this.

 

[jcd302]

Manual would have a pilot bushing in the end of the crank. For some reason people seem to overlook that.

 

[Captain Ledd]

We took an '88 4.0L, stuck a '94 cylinder head on it, popped in an 1982 258ci crank and rods, and new 4.0L pistons. was all auto stuff, put a manual flywheel from a newer cherokee (I forget year, but 1996+ at the very least), and bolted it to the original 1979 J10's 3 speed transmission. It did take some homework though.

In short, swap the flywheel (or flexplate, since it's an auto), and double check the pilot bearing diameter with the end of the auto trans input shaft. Actually the bearing for an auto trans is much less of an issue than a manual, but it's still good to have it. Pop the old one out from the donor engine, and compare the outside diameter with a new one (for the current engine with the cracked head) and replace it. it SHOULD be the same though.