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-   -   Next Winter's Project: Manual to auto swap in an '03 (http://www.wranglerforum.com/f282/next-winters-project-manual-to-auto-swap-in-an-03-a-19543.html)

jeeperman 06-28-2008 10:19 AM

Next Winter's Project: Manual to auto swap in an '03
 
Alright boys and girls, I am going to start collecting parts for next winter's swap from my NV3550 to a TF999 out of an earlier Wrangler. I know that some of you have done this, and others have enough knowledge on the subject to be dangerous (like me). I am kind of looking to build a complete parts list before I start (I know, nearly impossible to be complete, will have to make a few trips to the auto parts/hardware store during the project for odds and ends). Here is what I have for a list so far, please let me know if I am missing anything major that I am not taking into account:

Transmission (duh)
New brake pedal (asthetics)
Transmission cooler
Shifter (thinking Art Carr)
Kick-down cable
bellhousing
torque converter
transmission mounts
CPS sensor
associated fittings and trans lines for cooler and trans temp. gauge

I know that this is far from a complete list, but this is the first time it has hit paper, so I can build on it later. Please feel free to fill in the gaps.

Couple other questions: Can I bolt my NV241RC transfer case out of the Rubicon to this transmission, or are the outputs different? I know that they were never offered in the same Jeep, but they should still be compatible, right?

Alright, that's all I've got for now. Thanks in advance for all the help!:wavey:

30-284 06-28-2008 11:06 AM

Computer from an auto trans ?

Donn

jeeperman 06-28-2008 01:31 PM

Quote:

Originally Posted by 30-284 (Post 241579)
Computer from an auto trans ?

Donn

I am hoping to avoid that by using the older TF999 transmission, as it is manually controlled, and I don't need overdrive for the 1000-1500 miles per year that I put on my Jeep. I think that if I use the older transmission, my engine won't know the difference and will run normally.

parrot head 06-28-2008 02:11 PM

I believe the torque converter lock-up function is computer controlled:rolleyes:

Triple88a 06-28-2008 02:48 PM

didnt the older vw beetles have a torque converter connected to a manual tranny?

Jerry Bransford 06-28-2008 02:57 PM

The TF999, actually it's more accurately called a 32RH for the version used in earlier TJs, does need a lockup signal for the torque converter which is provided by the computer.

I'm thinking that because the 42RLE 4-speed auto that is used on 2003 and newer TJs like yours is integrated more completely with the computer, that the computer for a 2003 automatic TJ would not be happy with the lack of "reply" signals from the totally dumb 32RH. I'd suspect you may get a bunch of errors resulting in a Check Engine light by running a 32RH with a 2003 or newer computer if you installed one to provide the required torque converter lockup signal.

The only way around that issue I can think of is to install a manual on-off switch to lock & unlock the 32RH's locking torque converter.

If it were me though, I'd go for the 42RLE automatic since it's a 4-speed and you can keep the axle ratios as they are since it has an overdrive like your present manual transmission does. The 32RH does not have an overdrive so it would cause much higher engine rpms on the highway than you're getting now. This happened to me when I converted my 4.88 equipped TJ with a 5-speed manual to the 32RH 3-speed automatic a couple months ago. With 35" tires, it now turns over 2750 rpms at only 60 mph, the same rpms I used to get at 70 mph with the 5-speed. :)

GrnTJ 06-28-2008 04:53 PM

Get at me when you need help on this.

jeeperman 06-29-2008 08:12 AM

Quote:

Originally Posted by Jerry Bransford (Post 241618)
The TF999, actually it's more accurately called a 32RH for the version used in earlier TJs, does need a lockup signal for the torque converter which is provided by the computer.

I'm thinking that because the 42RLE 4-speed auto that is used on 2003 and newer TJs like yours is integrated more completely with the computer, that the computer for a 2003 automatic TJ would not be happy with the lack of "reply" signals from the totally dumb 32RH. I'd suspect you may get a bunch of errors resulting in a Check Engine light by running a 32RH with a 2003 or newer computer if you installed one to provide the required torque converter lockup signal.

The only way around that issue I can think of is to install a manual on-off switch to lock & unlock the 32RH's locking torque converter.

If it were me though, I'd go for the 42RLE automatic since it's a 4-speed and you can keep the axle ratios as they are since it has an overdrive like your present manual transmission does. The 32RH does not have an overdrive so it would cause much higher engine rpms on the highway than you're getting now. This happened to me when I converted my 4.88 equipped TJ with a 5-speed manual to the 32RH 3-speed automatic a couple months ago. With 35" tires, it now turns over 2750 rpms at only 60 mph, the same rpms I used to get at 70 mph with the 5-speed. :)

I was planning on running a switch on the dash for the torque converter, it's a pretty easy install from what I understand. A couple of the guys that I wheel with run this setup.

As for the engine needing the computer... What connection does it have to the NV3550? If the engine thinks that it has a manual hooked up to it, shouldn't it behave the same, even with an auto that is not computer controlled?

I am not that concerned about the higher revs without the overdrive because I am still running 4.10 gears in my axles (waiting on this swap...)

Thanks for the feedback guys, I really appreciate it, I am not arguing with anyone about anything right now, just trying to understand what the reasoning behind everything is...

And Grn - I will give you a call if I need another set of hands!:wavey:

Jerry Bransford 06-29-2008 10:27 AM

Quote:

Originally Posted by jeeperman (Post 241794)
I was planning on running a switch on the dash for the torque converter, it's a pretty easy install from what I understand. A couple of the guys that I wheel with run this setup.

As for the engine needing the computer... What connection does it have to the NV3550? If the engine thinks that it has a manual hooked up to it, shouldn't it behave the same, even with an auto that is not computer controlled?

If you run that switch to manually lock up the torque converter, you won't need to change your computer out. I only suggested the new computer thinking you'd not want to bother having to continually manually lock up and unlock the torque converter with a switch.

By the way, you also need a new flywheel. You'll also need a blind bearing puller to remove the pilot bearing and its spacer ring (or whatever its called) from the end of the crankshaft flange which is there for a 5-speed. :)

jeeperman 06-29-2008 12:30 PM

Quote:

Originally Posted by Jerry Bransford (Post 241806)
If you run that switch to manually lock up the torque converter, you won't need to change your computer out. I only suggested the new computer thinking you'd not want to bother having to continually manually lock up and unlock the torque converter with a switch.

By the way, you also need a new flywheel. You'll also need a blind bearing puller to remove the pilot bearing and its spacer ring (or whatever its called) from the end of the crankshaft flange which is there for a 5-speed. :)

Good to know! I will have to borrow one of those from my friendly neighborhood Auto Zone!

And I don't think I will mind locking up the converter "manually", once it's locked up, it will still kick down when needed, so once you are out of town, you can just lock it up and go!

Thanks again!:wavey:

Triple88a 06-29-2008 12:32 PM

the ecu doesnt control the shift points in an auto?

4.0l sahara 06-29-2008 03:56 PM

Quote:

Originally Posted by Triple88a (Post 241819)
the ecu doesnt control the shift points in an auto?

Not in a 32RH but in the 4 speed they are controlled by the ecm i belive.:)

jeeperman 06-29-2008 04:28 PM

Quote:

Originally Posted by 4.0l sahara (Post 241861)
Not in a 32RH but in the 4 speed they are controlled by the ecm i belive.:)

This is correct, that's why I like the 32rh, no computer bits, anything that goes wrong, I can hit with a hammer!;)

1BLKJP 06-30-2008 05:09 PM

Trip, the 32RH is a hydraulic tranny. The 42RLE is electrically controlled.

Interesting about the lockups. I have a 99TJ, but in 2k they put the lockup converters in. I now have a 2k 32RH in my rig with the lockup converter and it does in fact lock up on it's own. This talk with the computers makes me question why my 99 ECM is sending this signal to lockup the converter when they never had that option in that model.

Triple88a 06-30-2008 05:11 PM

I see well i thought i might mention it so its on the table and doesnt come up at the last moment. its those things we dont think about that slow the project down. Any one have any info on the torque converter to a manual tranny? Any one had an old bug? lol

wheelin352 07-05-2008 05:03 PM

i just did it really easy if i could of worked on it straight i would have been able to do it in a weekend by my self i havent hooked any wires up and it runs fine tho i do eventually need to hook up thr lock up the biggest problem i had was the pilot bearing spacer thing i couldnt find a puller for it that applied enough pressure to pull it out so i had to very carefully drill it and pull it out in pieces. also a tranny mount i had to drill new holes in my belly pan even with the mount from the auto and it right on a lip so that is going to have to change if you have an RE belly pan tho they should already have the bolt holes drilled cause that is the way my dads was, im not sure if thats the same with other after market belly pans.

willz 03-22-2010 02:01 PM

I have a 2000 sahara i went from manual to 3 speed auto trans that came out from a jeep sport since i still using the same ecm the torque converter does not lock up doe's any one does know how to manually make it work i know i can get another ecm programmed for that option.i was reading another coments about that but never mention how to do it.

Jerry Bransford 03-22-2010 03:27 PM

Quote:

Originally Posted by willz (Post 578497)
I have a 2000 sahara i went from manual to 3 speed auto trans that came out from a jeep sport since i still using the same ecm the torque converter does not lock up doe's any one does know how to manually make it work i know i can get another ecm programmed for that option.i was reading another coments about that but never mention how to do it.

Having done this conversion, it would just be a lot easier to simply swap in a PCM that was programmed for an automatic transmission. You can sell yours after buying the right PCM to recoupe most of the cost.

To do it manually would be a PITA & you'd have to remember to unlock the torque converter every time before you came to a stop. To control the torque converter would be simple, just an on-off switch providing 12 volts to the lock up torque converter connector located at the rear of the transmission.

Replacing your PCM with the right automatic transmission model PCM would also eliminate the need to do any wiring whatsoever as the torque converter's wiring harness is already present in your TJ and ready to connect.


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