Death of a tranny!!

[ParadiseMJ]

Well, the slave cylinder etal. finally gave up the ghost on my BA/10 in the MJ. I'm not real keen on dropping the BA/10, replacing the slave assembly and still ending up with a BA/10. I've been preening the AW4 in my shop for this, new hoses, NSS, filter etc etc. and it is as ready as it will be for the swap I've planned all along. So here is what I have:

 

AW4 (94) so no power/comfort switch. I got from a member on another forum locally, swears it was running perfectly when it was removed...he went with an AX15.

Torque converter - new

TQ converter seal - new

Tranny mount - new

Flexplate (1988 - new)

All wiring and connectors in good shape

Shifter, lever, plate, cable (all JY parts)

Center console, bezels.

Good cross member and good mounting holes (the rear most ones).

Motor mounts.

 

TWO GOOD WEEKENDS

 

Here is what I don't have:

AW4 TCU

ECU for AW4

 

Also, on the TPS...there are two harness plugs at the throttle body to the manual TPS. One is plugged in to the TPS, one is just sitting there, nothing to plug to. If I still had my XJ for reference this would be much easier, but it's history now.

 

So, the questions are:

1. Will I need a new (used) ECU for the auto?

2. Do I need a new (used) TCU for the auto?

3. Do I need an AW4 TPS?

4. Are there any wiring modifications I need to do?

 

Please steer me clear of any possible FUBAR's so I can be driving this thing in 2 weeks instead of pullingmy hair out (what's left of it) for months. I also know I need a different transfer case...working on that. I have the original 88 NP231J with 21 spline input, and I'd like to keep it since I rebuilt it last summer. If it's feasible to just re-do the input shaft on it or just find a 23 spline TC (hard to find here under $300).

[Alexia]

The AW4 TCU will operate independently of the ECU and can be used with a manual TCU. The only difference between the automatic and manual ECU is the automatic one contains the code to pull diagnostic codes from the AW4 TCU. That is how 1997+ Wranglers get away with swapping in the AW4 is by swapping in a manual transmission ECU.

 

For wiring you just need the appropriate harness for the transmission year and the correct year range of TCU. I believe you need a 1991 to 1995 ECU. After that it is wiring it up to power and a few other things.

 

Do you have the throttle kick down cable and throttle body bracket for the AW4? If you have these already on your manual setup including the spot on the throttle body to hook the cable up you should be fine. If you do not you will need the matching bracket, kick down cable, gas peddle with cable, valve cover with cable guides, throttle body, and some wiring work.

 

You will need a different transfer case or manage to find a 1991-1993 transfer case(23 spline, old gear cut) to scavenge an input from. The gearing cut on the input changed around 1993 so the newer input shafts will not swap cleanly into the old cases without some gear destroying carnage.

http://www.novak-adapt.com/knowledge/np ... _gears.htm

[ParadiseMJ]

So, the flexplate needs to be from an 87-90 (RENIX) or from the same years (HO) as the tranny??

 

I pulled the BA-10 and T/C yesterday. I'm now on the JY quest. T/C for $85...all cables, plates, shifters & linkage for AW4 tranny AND T/C for $40. I'll have to check the bracket for the TV cable (intact on the tranny) and the electronics.

[Alexia]

So, the flexplate needs to be from an 87-90 (RENIX) or from the same years (HO) as the tranny??

 

I do not remember there being a difference. I would go for the same years to be safe.

[Abyx]

The flex plate should be off of a 87-90 due to the tooth count for the CPS; an HO's flywheel/flex plate has a different count and if you use it in the Renix, your jeep won't fire.

 

If you need the TCU, I have one out of a 91 XJ that you can have for a couple of bucks plus shipping.

[ParadiseMJ]

Another question...sorry.

 

I can find NP 242's everywhere in the JY...yet no post 91 (23 spline) 231's. Pros & cons of a 242. Would a 96 242 be a direct swap?

 

I know they're a bit weaker than the 231 but this is NOT a crawler. More of a utility/fun/out camping truck. I'll never be doing Moab or the Rubicon in this truck. More like trips to Tahoe/snow/etc.

 

Opinions??

[Backdraft]

Go for it. I'd slap a 242 in in a heartbeat if it wasn't seeing severe duty. Simply because it offers a full time option.

 

 

 

 

BTW......your thread title was misleading! :doh:

[Alexia]

Another question...sorry.

 

I can find NP 242's everywhere in the JY...yet no post 91 (23 spline) 231's. Pros & cons of a 242. Would a 96 242 be a direct swap?

 

I know they're a bit weaker than the 231 but this is NOT a crawler. More of a utility/fun/out camping truck. I'll never be doing Moab or the Rubicon in this truck. More like trips to Tahoe/snow/etc.

 

Opinions??

 

The 1996 NP242 will work with the 1994 AW4 as long as the input shaft on the NP242 is the correct length.(Probably need a medium length shaft.) This is so mixed you will just have to figure it out. A NP242 behind another AW4 should have a medium length shaft in most cases.

 

The NP242 is just as strong as the NP231 when in part time mode. In full time mode the power travels through other parts that are not as strong.

[carnuck]

Just for future reference, the flexplate or flywheel needs to always match the type of EFI used as well as the trans.