How to wire up a NP 236 in place of a 136.

[Captn. Crunch]

I just wanted to double check that the NP236 case fits and bolts right in. The clocking is good? And the front drive shaft clears the cross member , etc.

Yes sir. Direct swap out with the NP136. No mods required. Even the original support brace from the 136 bolts up to the 236.

The 136 and 236 are identical in every way except of course for the low range. Cases, shafts, seals. Every part of the 136 is found inside the 236. Encoder motors interchange. Same same

[photo_van]

The 136 and 236 are identical in every way except of course for the low range. Cases, shafts, seals. Every part of the 136 is found inside the 236. Encoder motors interchange. Same same

Does the 236 have 2wd?

[racrx7]

Does the 236 have 2wd?

Yes it does, but for it be true 2wd, the van needs to run a front axle disconnect setup.

[trip_south]

Thank you for this thread. I'm scrounging around for a tccm and wiring but was able to pick up the NP 236 case. It seems like based on your explanation that most of the original 136 wiring could be used fine with some additions.

[Captn. Crunch]

Yes you will be using your existing wire. All except one ground iirc. Then you will be adding a couple more to the encoder motor,wiring in the switch and pulling power from the fuse block. racrx7 has done a great job documenting the process. I think all that's left is the axle disconnect circuit and the power circuit from under the hood. If your in a pick and pull for your parts make sure you grab the plugs on the back of the four button switch. I had to make a special trip for those. Doesn't matter which style of switch as long as it says 4auto on it.
Also I believe the jury is still out on the tccm question. No one has yet to prove that an awd tccm will not support a 4wd system. I was right there.. Both tccm's side by side and my encoder motor was bad so I needed to put things back to the way it was.

[trip_south]

Hello,
Coming back to this thread after a couple months...I was just curious about whether there was anything else to know about wiring up the NP 236? This is a fantastic tutorial and I'm hoping to get started on this project shortly.
Additionally, while I have the NP 236 TC itself I do not have any associated wiring. Could someone guide me as to the required wiring and connectors in addition to that I'd pull off of my NP 136 in the van right now? Where's a good source for wiring?
Thank you for your help.
Jesse

[Captn. Crunch]

The only difference is the encoder motor plug. 136 has a four pin and 236 has a six pin. Visit a jy and pull that section of harness. All the rest is the same. Follow the instructions wire by wire as you build up the tccm plug

[trip_south]

Is the front axle disconnect circuit required to make this work? I read some hints of that in previous posts but do not see specific guidance.
Thank you for your help.

[racrx7]

Is the front axle disconnect circuit required to make this work?

Yes it does. The TCCM needs to know if the front axle is engaged or not before it will select any of the four wheel drive ranges. If the TCCM isn't fooled into seeing a front axle dissconnect, it will just fault out and stay in two wheel drive. We use a simple spst relay to trick the TCCM into thinking we have a front axle dissconnect.

I apologize for not having posted that circuit yet, but will try to soon. So many projects going on right now. #-o

[trip_south]

No worries, please don't apologize! This thread is a great resource. I just checked up on this thread after a couple months away in preparation for trying the swap this summer.

[photo_van]

so that's what that switch on the S-10 front axle is for, I connected to a light!

[RINNY]

Just picked up my NP 236 with the complete harness, tccm, and switch. The yard I got it out of has been promising it since Feb and finally delivered. 50 bucks more than the original quote but whos counting, lol. Here we go!!

[RINNY]

ok so I have a few questions and ya they are kinda dumb,lol
1) Do I need to use the TCCM from the 236?
2) Where is my TCCM located for the 136?
3) I thing I am going to wire the switch in first because it seems to be the most complicated part of the wiring?
4) Do I need a front axel disconnect or do some additional wiring?

Donor was an early 2000's Blazer going into a 2003 astro.

The wiring harness for the switch, I removed the pins from the donor black block and labeled them from the pin location they came out of, the plugs that were attached to the harness are still attached to it, I cut all the other wires off the plug ends. And of course the 236 with wires attached that I removed from the plug that was attached to the case, they all have the pins that came out of the plug attached..

Any and all suggestions are deeply appreciated.

[Captn. Crunch]

1- yet to be determined. I would have that answer if my 236 encoder motor hadn't been junk. If everything had worked I would have tried the AWD unit.

2- you will find your TCCM behind the parking brake assy. You will find it behind the front passenger side kick plate in the Blazer.

3- looks like you made out better with the wiring harness donation than I did. I was splicing for hours

[racrx7]

so that's what that switch on the S-10 front axle is for, I connected to a light!

Excellent idea! Especially for those running a manual select transfer case. =D>