Swapping from 42RLE to NV3550 5-Speed Manual

Maxbrownr8

Maxbrownr8

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Joined
May 23, 2018
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Location
Northern California
Hey everyone. I've got an 06' X with the 42rle automatic that experiences the occasional hard-shift and some slipping. Inching up to 140k miles on the jeep and I would realllllyyyy like to swap to a manual trans (preference). That being said, I have an opportunity to get EVERYTHING I need (including an NV3550 rebuilt 5k miles ago) from an 04' rubicon donor (PCM, wiring harness, trim, pedal and clutch assembly, ect, ect, ect.) I have some questions however regarding the driveshaft length differences, if it bolts up the same way to my np231 t-case (as opposed to the nv241 on the 04 rubi), and any possible computer errors when attaching the pcm from the 04 rubi to the 06 x. Also, how is the nv3550 from experience? I have heard mixed reviews. Before I was considering getting a remanufactured trans for around $2000 and swapping it in myself, but I have the opportunity to get everything I need for the swap (including the pcm) for much cheaper than that. Including someone crazy enough with a shop to help me complete the swap...
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@mrblaine, weren't you looking for a 42RLE locally, or was it the other way around and you were looking for a manual?

Just tagging you in this since the guy is in California and I remember you saying something about looking for a local donor.

I know this transmission needs a rebuild it sounds like, but who knows.
 
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Maxbrownr8 said:
Hey everyone. I've got an 06' X with the 42rle automatic that experiences the occasional hard-shift and some slipping. Inching up to 140k miles on the jeep and I would realllllyyyy like to swap to a manual trans (preference). That being said, I have an opportunity to get EVERYTHING I need (including an NV3550 rebuilt 5k miles ago) from an 04' rubicon donor (PCM, wiring harness, trim, pedal and clutch assembly, ect, ect, ect.) I have some questions however regarding the driveshaft length differences, if it bolts up the same way to my np231 t-case (as opposed to the nv241 on the 04 rubi), and any possible computer errors when attaching the pcm from the 04 rubi to the 06 x. Also, how is the nv3550 from experience? I have heard mixed reviews. Before I was considering getting a remanufactured trans for around $2000 and swapping it in myself, but I have the opportunity to get everything I need for the swap (including the pcm) for much cheaper than that. Including someone crazy enough with a shop to help me complete the swap...
View attachment 105978
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When they send you the picture of the PCM, you'll understand why this will be much harder than you want it to be. The 04 PCM is a 3 plug for manual or auto, yours is a 4 hole with the pins in the 4th hole for the auto, missing for the manual.
 
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mrblaine said:
When they send you the picture of the PCM, you'll understand why this will be much harder than you want it to be. The 04 PCM is a 3 plug for manual or auto, yours is a 4 hole with the pins in the 4th hole for the auto, missing for the manual.
Click to expand...

If I’m getting the new pcm and wiring harness for the manual with the trans, shouldn’t it be just a straight switch or am I completely off base?
 
Maxbrownr8 said:
If I’m getting the new pcm and wiring harness for the manual with the trans, shouldn’t it be just a straight switch or am I completely off base?
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I'm 99.5% certain you will have to swap the whole vehicle harness out to make it all work. Your CPS is on the right side near the starter. The one you are swapping in has the CPS on the left side right below the head on the engine. The connectors are not the same between the two.
 
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mrblaine said:
I'm 99.5% certain you will have to swap the whole vehicle harness out to make it all work. Your CPS is on the right side near the starter. The one you are swapping in has the CPS on the left side right below the head on the engine. The connectors are not the same between the two.
Click to expand...

Yikes... That sounds like a blast. I have the 04' harness available, but if I swap it, I guess then my biggest worry would then be that harness not completely matching up to the rest of the 06' connectors sensors and other components.
 
My bet is your hard shift problem is caused by the PCM, 05-06 models have PCM software bugs in the transmission controller. You'd be better off by just having your PCM fixed by Mark at @Wranglerfix who has figured out the programming errors and fixed them.

For the slipping, check the ATF level while the engine is running and the transmission is in Park. The engine MUST be running to get an accurate ATF level check. Even being slightly low can cause slippage. It's better for an automatic transmission to be slightly overfilled than underfilled.

If it's low, bring it up to full only with ATF+4 via a small funnel placed in the dipstick tube. If it doesn't say "ATF+4" in big letters on the front of the bottle it's the wrong stuff.
 
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@Maxbrownr8 The hard shift is processor failure on the tcm side of the Pcm.

As far as wiring harnesses are concerned, I am NOT the one to ask. @mrblaine I took on another warehouse from those 47 harnesses I sent you.
 
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