98 ZJ 42RE into a 98(ish) TJ
- Thread starter Franky-N
- Start date
If cost is your biggest hurdle I'd be mowing some extra lawns or working a bit of overtime before I'd go through all the work of putting a 42RE in there. With those gears and tires it might last one trail ride. HUGE waste of time and effort. There have to be some salvage yards around you that have a used 32RH for a couple hundo you can throw in. At least it will be an easy swap instead of trying to mod the Jeep to fit the 42RE, a worse transmission, into it. 
If cost is your biggest hurdle I'd be mowing some extra lawns or working a bit of overtime before I'd go through all the work of putting a 42RE in there. With those gears and tires it might last one trail ride. HUGE waste of time and effort. There have to be some salvage yards around you that have a used 32RH for a couple hundo you can throw in. At least it will be an easy swap instead of trying to mod the Jeep to fit the 42RE, a worse transmission, into it.
First of OT is off table I’m a salary employee
Second I’ve owned many ZJs and WJs with a 42re and only 1 ever had an issue - heat was my worst thing to fix.
The shaft it rides on does have a snap ring in the trans. And the 2 pressure rings (As I know them to be called) are on that shaft into the main body. So, it does require a full tear down.
You know buying, building and owning Jeeps is supposed to be cool creative thing. Not a blast others cause they think differently.
And when you try and do something different such as I am with using this transmission as a for now option. You really HOPE you get positive input not all the negative Naceys.
At the end of the day, this is what I have to work with, it's what I'll use. I was just hoping to sidetrack install headaches with some knowledge being shared.
But I guess like always I'll learn and figure it out. Getting it all in no issues, making the computer talk to the dash well learning curve.
FYI - I'm far from Green in the Jeep world; I've owned 47 Jeeps and built 30 of them for myself since 2007. I do know this is not the best option transmission but it's what I have to work with for now. You might not agree with it but hey it's my Jeep not yours.
And when you try and do something different such as I am with using this transmission as a for now option. You really HOPE you get positive input not all the negative Naceys.
At the end of the day, this is what I have to work with, it's what I'll use. I was just hoping to sidetrack install headaches with some knowledge being shared.
But I guess like always I'll learn and figure it out. Getting it all in no issues, making the computer talk to the dash well learning curve.
FYI - I'm far from Green in the Jeep world; I've owned 47 Jeeps and built 30 of them for myself since 2007. I do know this is not the best option transmission but it's what I have to work with for now. You might not agree with it but hey it's my Jeep not yours.
As was asked before what difference will the 42RE transmission have compared to the 32RH? Is the TCM integrated into the PCM or separate? How much wiring is it going to require?
Remember you asked on a public forum so you're going to get all comments. And YES I understand the it's what I have... There are times though where you have to ask just because I have it should I? It sort of like the guy who's got a SBC or SBF sitting in the shed... And wants to swap it into his TJ... There are times it isn't the smartest option.
But if the needed wiring is minimal and you can make the 42RE work then I don't see why not... Yes IMO it's a lot of work to go through when you're planning on swapping in a Hemi sometime in the next 2 years.
If I have other transportation I might consider letting the Jeep sit for a year while I saved funds and then do the swap ASAP... I've been down these rabbit holes. And I'm retired & on a fixed income so I do understand not having extra funds and acquiring some isn't easy either.
Remember you asked on a public forum so you're going to get all comments. And YES I understand the it's what I have... There are times though where you have to ask just because I have it should I? It sort of like the guy who's got a SBC or SBF sitting in the shed... And wants to swap it into his TJ... There are times it isn't the smartest option.
But if the needed wiring is minimal and you can make the 42RE work then I don't see why not... Yes IMO it's a lot of work to go through when you're planning on swapping in a Hemi sometime in the next 2 years.
If I have other transportation I might consider letting the Jeep sit for a year while I saved funds and then do the swap ASAP... I've been down these rabbit holes. And I'm retired & on a fixed income so I do understand not having extra funds and acquiring some isn't easy either.
Thank you for a straight reply. And it’s been a back and forth for me on this. Biggest concern is if it sits and waits will I ever get to it. As for the Hemi I’m fast trying to secure funds but things are tight.
I have dug enough info up that if I retain all the ZJ under hood harness and computers I may only need move a few bulk head wires (if any at all) we will see. I’m about 2 weeks out from a need to know date. I still got to pull stuff apart.
I for one want to see how you manage the wiring. Here's a thread on the topic.
https://wranglertjforum.com/threads/42re-transmission-swap-wiring.51148/
My Jeep sat for 10 years but was due to health issues so I understand not wanting to have it sit.
When you start this think about keeping this thread going. Keep us updated and let others know what is needed.
Nobody is bashing you, just trying to give you a heads up on what might be involved. In my experience with Jeeps and swapping engines and transmissions into vehicles that did not come with them, the 42RE won't just bolt in without some mods. The wiring is also different since the 42RE is electronically controlled, and since this isn't a popular swap into a TJ, it's kinda tough for us to give a good idea on what to expect. It may also make your Hemi swap more difficult when you have to make changes to the already modified wiring since you will be going from a wiring harness modded for the 42RE instead of the factory setup.
Things that will probably be different off the top of my head:
-Trans control electronics and wiring, how the TCM works
-Transfer case input shaft might be different requiring the ZJ T-case (is that an NP242 or NP231? I think most ZJs were NP242 or NP247)
-Rear driveshaft / front drive shaft lengths possibly won't work
-Transmission mount/cross member mods/shifter?
All of these are things you would need to confirm on what has to be changed, and then changed again for the Hemi swap. Just because you have a 42RE doesn't mean putting it in will not have extra costs either unfortunately.
All I'm saying is that is a lot of custom work to make a "so-so" transmission fit in, just to have to undo all that work later down the road for the Hemi swap. If it was me and I was short on funds, I would 100% wait until I could get a good used 32RH which can be swapped in on a Saturday afternoon and is a 2-3 beer job.
Things that will probably be different off the top of my head:
-Trans control electronics and wiring, how the TCM works
-Transfer case input shaft might be different requiring the ZJ T-case (is that an NP242 or NP231? I think most ZJs were NP242 or NP247)
-Rear driveshaft / front drive shaft lengths possibly won't work
-Transmission mount/cross member mods/shifter?
All of these are things you would need to confirm on what has to be changed, and then changed again for the Hemi swap. Just because you have a 42RE doesn't mean putting it in will not have extra costs either unfortunately.
All I'm saying is that is a lot of custom work to make a "so-so" transmission fit in, just to have to undo all that work later down the road for the Hemi swap. If it was me and I was short on funds, I would 100% wait until I could get a good used 32RH which can be swapped in on a Saturday afternoon and is a 2-3 beer job.
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