np136 vs np236

FROM AWD'S TO 2-SPEED MANUAL SHIFT, IF IT LINKS THE REAR AXLE TO THE FRONT AXLE, POST IT HERE.

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Re: np136 vs np236

Post by Captn. Crunch »

The 136-236 and 436 all share the same clutch pack. The only way to get away from the parasitic power drop is to go to a manual case. Anything with a clutch pack will be putting some rotational force to the front diff due to the clutch pre-load. I did see someone at zr2usa playing with the wave washer and was freeing things up that way. Don't know if be has found a permanent solution
Captn. Crunch
"I don't beat my rig-I use it to it's maximum potential"
1994 Safari conversion (sold) and miss'n it!
1999 Safari SLE AWD junked
2003 GMC Safari AWD SLT
cast iron Torsen equipped front diff
S-10 leafs-G80 rear w/3.73’s
2” body lift w/Falken Wildpeak AT’s

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Re: np136 vs np236

Post by Captn. Crunch »

Update time!
So here's where I'm at. The 236 is installed. Well actually it's a 136 with 236 internals. I am still running to 136 encoder motor because I don't have the wiring for the four pin 236 encoder motor. As I've mentioned before I am a sponsored subscribed member at ZR2USA.COM. I joined because of the huge number of folks who run the 236 tc in their zr2's. A lot of them truly hate this case due in no small part to all the electronics involved in just asking your truck for four wheel low. A lot of these guys wheel pretty hard and sooner or later end up in water that's deeper that they thought. Fried electronics are sure to follow. I happened across someone in the process of converting from 236 to a manual 231. He has kindly offered to box up and ship the blazers tccm, encoder motor wiring, four button dash switch and harness.
This should be the last of the pieces and parts I'm gonna need to get me to the point where I find out if this is even gonna work. He said he'd ship next week so stay tuned and keep your fingers X'd. Well that's all for now-off to Engishtown to watch some drag racing !!!!!
Captn. Crunch
"I don't beat my rig-I use it to it's maximum potential"
1994 Safari conversion (sold) and miss'n it!
1999 Safari SLE AWD junked
2003 GMC Safari AWD SLT
cast iron Torsen equipped front diff
S-10 leafs-G80 rear w/3.73’s
2” body lift w/Falken Wildpeak AT’s

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Captn. Crunch
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Re: np136 vs np236

Post by Captn. Crunch »

Captn. Crunch wrote:The 136-236 and 436 all share the same clutch pack. The only way to get away from the parasitic power drop is to go to a manual case. Anything with a clutch pack will be putting some rotational force to the front diff due to the clutch pre-load. I did see someone at zr2usa playing with the wave washer and was freeing things up that way. Don't know if be has found a permanent solution
Long time no post. My bad to anyone paying attention to whatever this is.
Lets start with an update. I recieved all of the pieces I will need to get the 236 case functional. Thanks Casey! I took this road knowing that GM is lazy and hates making one off items for their vehicles. I felt sure they would underutilize 4x4 parts for our awd. I was proved right when I was able to put 236 internals in a 136 case. The 136 encoder motor operated the awd portion of my fs236. fs is short for Frankenstein by the way.
The plug for the 4x4 tccm I recieved is the same plug as our awd tccm but with more circuits. The circuits in ours match pin for pin the 4x4 plug. I simply need to add the missing circuits to my exsisting plug and run the wires to their final destination. All that is left is to complete those dozen circuits, swap tccm' and encoder motors, install the switch and X my fingers.
In a previous post we talked about having to deal with clutch pack preload and I think I might have figured out how for it not to be a factor. I will be putting a limited slip unit in a cast iron front diff. The recent discovery of someone having a torsen type carrier for the 7.2 got me thinking. I know - OH NO! The thing about Torsens is they need both wheels on the ground or they won't work. With that said if I used a torsen with the 236, it's preload issue and two solid axles such as our vans have, I may suffer from crow hopping and binding in low speed cornering situations. If I use a torsen type with an S-10 two piece axle I would be able to run in 2HI with axle disengaged. Any torque being sent forward would be dispersed by the torsen resulting in a neutral front end and true 2HI. For 4x4 I would pull the cable to lock the axle ans select 4AUTO. This would be the same as our 99+ awd with power being sent forward during wheel slip only. The one difference would be now with two axles engaged the torsen will put power to both wheels and the power will be shifted side to side according to available traction. I will also have the option of 4HI where the tc will lock, putting power full time to the front end. For extreme situations I will have 4LO at my disposal with geared reduction and power full time to the front diff. So with Torsens front and back, true two wheel drive, on demand awd, 4HI-LO all available and with power to all four tires, this should be kinda neat.
My one concern is having power to both front wheels on snowy roads. I know adding the torsen to the rear changed how the van drove in the snow. I'm pretty sure there will be some handling characteristics that will change when I do the front. I can only hope they are positive or at least manageable and changes in driving technique can compensate.
Seeings as no one has done this and when it's done it's gonna be the only one on he planet ice got nobody to ask from here on in. Feel free to let me know what you think cause when questions are asked its a good thing
Captn. Crunch
"I don't beat my rig-I use it to it's maximum potential"
1994 Safari conversion (sold) and miss'n it!
1999 Safari SLE AWD junked
2003 GMC Safari AWD SLT
cast iron Torsen equipped front diff
S-10 leafs-G80 rear w/3.73’s
2” body lift w/Falken Wildpeak AT’s

truC
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Re: np136 vs np236

Post by truC »

Great stuff man. I recently join the site and have read this thread. I wish I was not so challenged when it comes to the electronics side of things.

I am currently considering going this rout with the transfer case swap. I feel very comfortable fabing up the mechanical lever connection to the TC.
Life is short, get out and get dirty.

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Re: np136 vs np236

Post by Captn. Crunch »

truC
Thanks for following along. It's been fun thinking this thu. Just a word of caution to you. If your gonna do a tc swap and want mechanical linkage stay away from the 236. There are better cases like the 231 for that. Or you can wait til I'm done and see if the wiring is beyond you. I'm thinking its not gonna be that bad as I get closer to it. Read up on some of the other guys builds and then make up your mind. Just a thought
Captn. Crunch
"I don't beat my rig-I use it to it's maximum potential"
1994 Safari conversion (sold) and miss'n it!
1999 Safari SLE AWD junked
2003 GMC Safari AWD SLT
cast iron Torsen equipped front diff
S-10 leafs-G80 rear w/3.73’s
2” body lift w/Falken Wildpeak AT’s

racrx7
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Re: np136 vs np236

Post by racrx7 »

Great info and reading here. Gotta appreciate your determination to see this thing thru. Hope it all works out as this sounds like it may me an avenue for me.
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Re: np136 vs np236

Post by racrx7 »

While rummaging thru my local PNP yard, I came across a nice NP246 that was already pulled by someone else. It's application is listed as for use in the 1500 class full size trucks and Utes. It uses a 6 bolt mounting verses the 5 bolt in the 136 and 236. I'm wondering if the transfer case adapter on the transmission is changed to fit the 246, would the clocking be correct? Hmmmm.
O3 Astro 4X4
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Dropped front IFS axle
Journeys rear spring hangers and shackles, S-10 leaf springs, 2" body lift
255/70-16 BFG KO2's on 16x8 Fuel Revolvers

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Re: np136 vs np236

Post by Captn. Crunch »

Here ya go! Give this a read if your thinking of heading down the 246 path. This was done with a ZR2 which have the same front diffs sooooo......

http://www.zr2usa.com/mboard/index.php? ... 4&hl=np246
Captn. Crunch
"I don't beat my rig-I use it to it's maximum potential"
1994 Safari conversion (sold) and miss'n it!
1999 Safari SLE AWD junked
2003 GMC Safari AWD SLT
cast iron Torsen equipped front diff
S-10 leafs-G80 rear w/3.73’s
2” body lift w/Falken Wildpeak AT’s

racrx7
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Re: np136 vs np236

Post by racrx7 »

Here ya go! Give this a read if your thinking of heading down the 246 path. This was done with a ZR2 which have the same front diffs sooooo......
Excellent!! Thank you!! :cheers:
O3 Astro 4X4
Image
Dropped front IFS axle
Journeys rear spring hangers and shackles, S-10 leaf springs, 2" body lift
255/70-16 BFG KO2's on 16x8 Fuel Revolvers

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Re: np136 vs np236

Post by Captn. Crunch »

More 246 tc info from ZR2USA

does anyone have the part number for the transfer case adapter for this swap?
Megabuddys
Today, 04:42 AM
I dont have a part number, but the adapter is from a 99-07 4l60e equipped 4wd suburban, blazer, tahoe, silverado, etc. etc. Super easy to find.
Captn. Crunch
"I don't beat my rig-I use it to it's maximum potential"
1994 Safari conversion (sold) and miss'n it!
1999 Safari SLE AWD junked
2003 GMC Safari AWD SLT
cast iron Torsen equipped front diff
S-10 leafs-G80 rear w/3.73’s
2” body lift w/Falken Wildpeak AT’s

racrx7
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Re: np136 vs np236

Post by racrx7 »

http://pages.ebay.com/link/?nav=item.vi ... ID=EBAY-US

That looks like the one he used. It's 3/8" longer and the mounting pad is more forward than our 136's. Would have to do a crossmember mod like Mega did.

Then there's this one. I need to get the dimensions for it.

http://pages.ebay.com/link/?nav=item.vi ... ID=EBAY-US

Any guess to its length?
O3 Astro 4X4
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Dropped front IFS axle
Journeys rear spring hangers and shackles, S-10 leaf springs, 2" body lift
255/70-16 BFG KO2's on 16x8 Fuel Revolvers

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Re: np136 vs np236

Post by Captn. Crunch »

Why guess when there's Google!
Note trans nomenclature


eBay › ... › Automatic Transmission Parts
Mobile-friendly - Casting # 15724745. The Early ... Part Brand: Gm Oem Part, Surface Finish: Fits 4L80-E Gm Trucks 4wd 4x4 4 Wheel Drive. Brand: ... This has an overall height ( Front to Back) of 2 3/4".

I'm glad you're looking into this. There is no such thing as TMI here. Meggabuddy is pushing 600rwhp in his ZR2 and needs these types of upgrade. I will never be able to break a 236 due to over-torque so I'm good with bolt up mods. Feel free to pursue what would be required to get an NP246 under our vans. Who knows-you might end up with a sticky.
Captn. Crunch
"I don't beat my rig-I use it to it's maximum potential"
1994 Safari conversion (sold) and miss'n it!
1999 Safari SLE AWD junked
2003 GMC Safari AWD SLT
cast iron Torsen equipped front diff
S-10 leafs-G80 rear w/3.73’s
2” body lift w/Falken Wildpeak AT’s

truC
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Re: np136 vs np236

Post by truC »

Wow, some really good proof of concept going on here. Thanks for posting all your findings, and for the advice of the 231.

Last time I went down the rabbit hole of mods it ended up just being one mod upgrade after another sorting out the weak link.

I read somewhere on this site that in 4lo the tranny wasn't shifting, have you found any such issues?
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Re: np136 vs np236

Post by Herbie »

truC wrote:
I read somewhere on this site that in 4lo the tranny wasn't shifting, have you found any such issues?
Probably referring to the tranny holding you in 1st/2nd in 4Lo. If it tries to go to 3rd the difference in rpm vs. vss signal causes a minor freakout. The good news is that we share an ECU with the Bronco, so if you add a wire to the ECU harness that is grounded when in 4Lo, the ECU understands what's up and all works as expected.
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Re: np136 vs np236

Post by Captn. Crunch »

Ya I'm sorry guys - I've been a slug these last couple of weeks. I know I'm close to making this happen and people wanna know. Work has offered up weekend work and being a glutton for punishment and maybe just a glutton I've signed on for sat/sun work. It doesn't happen very often so jump on the double time!
22 days straight, pushing 60 and handicapped I got nothing in the tank when it comes to the van. So yes I'm a slug and I'm sorry I haven't figured this 236 wiring thing out yet.
Thanks Herbie. I also remember reading about this shifting issue. I wasn't gonna worry bout it until it happened and hit the search button if it did.
Captn. Crunch
"I don't beat my rig-I use it to it's maximum potential"
1994 Safari conversion (sold) and miss'n it!
1999 Safari SLE AWD junked
2003 GMC Safari AWD SLT
cast iron Torsen equipped front diff
S-10 leafs-G80 rear w/3.73’s
2” body lift w/Falken Wildpeak AT’s
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