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

[rvflyfish]

racrx7, Capn, Snowgeek, awesome info. Thank you for all your time and energy!

For those unable to see images, someone on Expo posted plug-ins for Firefox and Chrome that fix the Photobucket problem: http://forum.expeditionportal.com/threa ... ket+images

Unfortunately I bought a 231 before finding this info so I'll have to offload that and grab a 236.

I also want to grab a 246 and swap its heavier duty internals into the 236 shell as racrx7 details here: http://astrosafarivans.com/bb2/viewtopi ... brid+build

racrx7, in that thread you say, "The front output shaft shown above the planetary on the right is from the 246 and will NOT fit in the 236/136 case. It uses different sized bearings not compatible with the 236/136 cases. That being said, the 246 rear case half cannot be used in conjunction with the 236/136 front case half." So did you have to swap the 236 front output shaft onto the 246 planetary?

Thanks again guys. I'm a noob but I feel like this thread can help me pull both of these jobs off!

[Captn. Crunch]

Thanks for the link for the photo bucket patch. That was a heartbreaker when all those images vanished let me tell ya.
Good for you aiming high on the tc swap. Like my dear old mother used to say “ anyone can pee on the floor - be a hero and crap on the ceiling.”

[rvflyfish]

Your mom sounds like a real character. That's great.

Yeah the Photobucket thing. Ugh. Felt like they really screwed everybody. That's why I have no issue posting up a workaround. Glad it helped you.

[unclebill]

If anybody out there is still contemplating doing the 236 conversion, a little advice.

First, while acquiring the transfer case grab all the related wiring you can. This includes at least one control module connector and the wiring for the split front axle. That way when you build up the wiring harnesses you can put things together so that relay used to fake having a front axle switch can simply be unplugged when the axle gets installed. Also, get one of each kind of control switch if possible (with connectors). It takes a while to figure out how to install one in a way you can live with, maybe like moving heat/AC controls to the top console or sumpthin'.

I had picked up my 236 out of a Blazer that had the drive shafts pulled so a little work involved in getting the 5 bolts out was all that was required to drop the case. This sat in the garage for a few months while other things happened. On of those other things was that the lube place I was using left a cap loose and the front axle trashed itself on a trip out of town. Got the replacement from a Blazer that had had the engine pulled and dropped the axle from the top, about 30 minutes. Top bolt is a bear otherwise.

Anyway, the point is I probably wouldn't have swapped axles without the mishap, but the parts tally for xfer, axle, and harnesses was around $250. And had I known that from the get go I probably would have just picked up the whole package at the beginning. And, the way I think is it made a lot of sense to have the split axle if I was going to have a 2wd output anyway. The time for changing both is a long day (including the requisite breaks).

If you don't know how to solder, either use some of the left over harness wire to learn, or have a friend that knows how help. It seems that butt connectors aren't reliable over the long term and know the worst times and places to fail. Shrink sleeves should be used and the sealing type should be used on any exterior connections, which you should try hard to eliminate. If necessary order new connectors for the plug housings so you can install long enough wires to get inside - if you cant salvage the old ones. Finally, the weatherproof connectors are available in quantity cheap at the U pull it places, Try to pick up a couple each of 1-8 wire connectors. If you do need to splice under the vehicle, this is the best way.

[RINNY]

It lives!! The transfer case is now shifting into all 4 modes and has been driven on very soft sand. I am having a shifting problem in 4L. The transmission does not seem to want to shift out of 1st gear, it does on some occasions but not as it should. Progress but still not completely rite.

[racrx7]

It lives!! The transfer case is now shifting into all 4 modes and has been driven on very soft sand. I am having a shifting problem in 4L. The transmission does not seem to want to shift out of 1st gear, it does on some occasions but not as it should. Progress but still not completely rite.

YAY!! Finally!! Lol. Did you run the necessary wire to the ECM that tells it you are in 4L?
Congrats!!

[Snowgeek]

RINNY, congrats man! Hopefully that ecm wire is all it will take to get you shifting in 4L!!

As to the other problems you faced

stuck in 4L - frozen encoder motor
- resolved with new encoder motor
No shift into 4L - wire connectivity in orange connector
- new wire run and improved crimp on the end

What other problems have you tackled. I plan on adding each one of the issues / resolutions to the pdf in a trouble shooting section at some point.

Snowgeek

[Snowgeek]

RINNY, congrats man! Hopefully that ecm wire is all it will take to get you shifting in 4L!!

As to the other problems you faced

stuck in 4L - frozen encoder motor
- resolved with new encoder motor
No shift into 4L - wire connectivity in orange connector
- new wire run and improved crimp on the end

What other problems have you tackled. I plan on adding each one of the issues / resolutions to the pdf in a trouble shooting section at some point.

Snowgeek

[RINNY]

The other problem was to do with my V8 swap and the computer that I used. The motor was out of a 2002 chevy express. You do not want to use this motor and computer because of the way the transmission talks to the PCM. In my 2003 Astro the data went thru the PCM, but in the 2002 express it goes directly to the dash. I had to piggyback the '03 PCM onto the '02 express PCM so the transfer case would recognize neutral and my shift indicator lights would work, I am still chasing a pretty consistent gremlin to do with the temp gauge, and a sporadic one in the fuel gauge. Would have been better off using a motor out of a passenger vehicle based PCM like we have in our vans. The other thing that should be addressed if doing the NP236 transfer case swap in a V8 driven vehicle is you really need a 12 disc clutch pack not a 10 disc like is standard in the NP236. They are interchangeable the v8 will burn up the 10 disc pack.

[RINNY]

It lives!! The transfer case is now shifting into all 4 modes and has been driven on very soft sand. I am having a shifting problem in 4L. The transmission does not seem to want to shift out of 1st gear, it does on some occasions but not as it should. Progress but still not completely rite.

YAY!! Finally!! Lol. Did you run the necessary wire to the ECM that tells it you are in 4L?
Congrats!!

I will be getting to that at some point in the near future. I bit off an awful lot doing this as I did a 5.7L swap. I also put a Detroit LSD in the rear and am building a front diff with one. The front diff should be going in before April.

Couldn't have done it without you my man!! As a matter of fact Captain Crunch was instrumental with some hands on diagnostics to button it all up. He is about 20 minuets away from me. Very methodical and particular when and where it counts he is!!

[Snowgeek]

RINNY, so I will be very curious how this works out for you!

Few questions:

Does the np236 bolt right up to the 5.7 and / or would a tougher np246 have worked?

It seems that the express guys have not figured out how to make this work yet, based on your intel does it seem that this could be an option on a full size van?

Ryan

[RINNY]

RINNY, so I will be very curious how this works out for you!

Few questions:

Does the np236 bolt right up to the 5.7 and / or would a tougher np246 have worked?

It seems that the express guys have not figured out how to make this work yet, based on your intel does it seem that this could be an option on a full size van?

Ryan

The NP 236 bolts rite in behind the 4L60E transmission, I believe modifications to the driveshaft's might be necessary for a 246, racrx7 would know that and might be covered on the thread he did on the hybrid 236/246 transfer case.

I do believe express vans were available in 4WD up to 2017. Quigley I am sure will do it for any van. I had a new 2006 Extended E350 with a 6.0L (sucked) that was built by Quigley. To clarify the 6.0L diesel sucked, the Quigley 4x4 upgrade was friggen awesome!!

[Snowgeek]

Ok wiring guys.... I just got done doing a final cut down on the wires for the 236 harness. This required pulling each wire out of the orange TCCM connector cutting splicing and covering each wire.

Everything seems to be working properly but the 4hi indicator light on the switch is dimly on all the time. As you select each setting 4 auto, 2 hi, and 4 low the lights follow your selection and are on brightly (4 hi light on all the time) If I select 4 Hi the dim 4 hi light is on and continues to be dim.

Any thoughts where I should start looking for this quirk? Prior to beginning this the lights all worked properly,

Thanks,

Ryan

[Herbie]

That sounds like there's a sneak short somewhere - something not perfect in the wiring. Dim lighting likely means that there's a small potential (voltage difference) between each end of the lamp. That alone could be down to a sketchy connection, but the fact that it doesn't light up full-bright when you select 4Hi means that it's also not toggling correctly in that mode.

Hate to say it, but you'll want to re-check all your splices both for continuity and to rule-out shorts to all the other pins. It's tedious, but necessary. Focus in particular on the 4Hi indicator leads to/from the TCCM as well as power and grounds.

[Snowgeek]

Herbie, this is exactly where my head was going but I would have never been able to say it so clearly. In the end tracing things down is not so bad, I have every wire labeled at each end and cataloged. I guess my dash really didn't want to be put back together any time soon :-)

Your dash blank has been staring at me from my desk at the bike shop I will ship it out tomorrow.

Ryan