I know there's a bunch of threads on here about this and I've been lookin' through 'em. I was wondering if anyone could summarize this for me.
I want to upgrade my 2.5L 5 spd to a 4.0 5 or 6 spd. What all do I need other than the engine, trans/clutch kit, and computer? I'm pretty new at engine things, been doin' body work for years and smaller engine repairs/work.
Im in college so I want to start piecin' stuff together now so it won't kill me later. I plan on running the wiring for my winch and another set of lights while everything is out, little easier. Also, should I get a MML and put it in while I'm doing the engine so that I don't need to do it later? Should I go ahead and get a 1 in. body lift and put that on too while most of the weight is outta the Jeep?
Theres no where better to get any information than from y'all, so I figured I'd ask.
I cant stress enough, do not go with a 2000 or higher.. for 1 you'll be looking at converting to distributorless coil-on-plug (which means you'll have to swap the wiring harness).. plus you'll be going with the worst head ever made for the 4L.. head casting 0331 (00'-02') were most prone to cracking, other than that all 0331 heads had exhaust ports half the size as the prior heads, and are garbage. Do yourself a favor and go with a 98-99 motor, since you're probably right you cant go back but you can go forward.
and if you source the motor out of a cherokee or grand cherokee, they switched to the crappy head sometime in 99 IIRC.. easiest way you'll be able to tell (if the motor is complete) is the intake manifold will be horseshoe shaped, vs more boxy shaped (if looking from the top)
I just swaped my 6speed out of my 06 2.4L. For the nv 1500 5 speed Was not happy with the 6 speed..6th gear was useless on the highway... It dropped the rpms so low that it would not allow the engine to reach its power band. And I would actually slow down on the highway. Foot to the floor my jeep would not go over 2400 rpm and not over 60 mph. maybe it's better in the 4.0. I've never driven one
I just swaped my 6speed out of my 06 2.4L. For the nv 1500 5 speed Was not happy with the 6 speed..6th gear was useless on the highway... It dropped the rpms so low that it would not allow the engine to reach its power band.
So to avoid paying under $1K for new gearing for your axles, you paid, how much?
Under a grand. About 700. But it's a completely different vehicle!! I can do 80 plus mph on the highway at less than 2800 rpm in 5th. Worth every penny! And the 2.4L actually performs better with the 5 speed.
So I'm lookin for an 98 or 99 and an AX15 5 spd trans.. Or do ya recommend a diff trans? Then I'll need a new intake, lines for the 2 injectors, radiator and computer. Can I use the transfer case I already have or do I need a new one?
As ya can tell, don't really know about this.. Haha
Just a small town country boy who loves Jeeps
Charlotte - 1998 Wrangler Tj 2.5L
1.25' Rough Country BL & 1' JKS MML, 3' Zone Offroad Suspension & Disconnects, Brooks Custom Concepts Rocker Panel Guards, Poison Spyder Custom Trail Stinger, Engo 10K, Cragar 352's, 33x12.5x15 Cooper Discoverer ST's and more.
What transfer case do you have? And yeah an ax15 will be the easiest to source I imagine.. but the nv3350 and whatever the 6 speed is called will bolt right up.. you're also looking at having new driveshafts made and motor mount brackets welded onto the frame