Quest for another 2 speed w/AWD transfer case

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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LiftedAWDAstro
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Quest for another 2 speed w/AWD transfer case

Post by LiftedAWDAstro »

Plowed the driveway tonight and realized I HATE this 136 transfer case for plowing! ](*,) Got stuck because of the delay in engaging. I also want low range...the tranny is taking a beating. We have about 6" of real wet heavy crap and a very soft, wet ground. So....

What I am going to do is basically what photo_van did to his van. I want AWD, and 4 LOW. In the process I will get 4 HIGH and 2 HIGH as well. I am thinking a NP236 or NP246 is the way to go. This won't be a fast process but it WILL have to happen before next winter for sure! If the lengths are correct and I don't need to modify the driveshafts, it may happen sooner rather than later.
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy
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MountainManJoe
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Re: Quest for another 2 speed w/AWD transfer case

Post by MountainManJoe »

Bookmarked!

Topic author
LiftedAWDAstro
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Re: Quest for another 2 speed w/AWD transfer case

Post by LiftedAWDAstro »

Info I am finding as I go along...

Parts breakdown:

Image

NP246 info:
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy
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Re: Quest for another 2 speed w/AWD transfer case

Post by MountainManJoe »

too bad those images are missing.

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Re: Quest for another 2 speed w/AWD transfer case

Post by photo_van »

Electric shift eh? What's the difference between the 236 and 246? Look's like you can get it with 27 spline input \:D/
1998 AWD/4WD
4" lift, 31x10.50's, NP 242j/c hybrid, 4.10 gears, S10 front disconnect, rack & pinion steering, trans cooler, rock sliders, ARB fridge, house battery and 100w solar, swing out rear rack with foldout camp table, bed and passenger swivel chair
dirt bag camping rig
1981 Toyota 4x4 pu
1974 John Deere 710
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Re: Quest for another 2 speed w/AWD transfer case

Post by MountainManJoe »

The 246 is just heavier duty.

Topic author
LiftedAWDAstro
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Re: Quest for another 2 speed w/AWD transfer case

Post by LiftedAWDAstro »

Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy

Topic author
LiftedAWDAstro
I have my van tatooed on my cheeks
Posts: 4379
Joined: Sat Sep 09, 2006 3:35 pm
Location: New Haven, NY

Re: Quest for another 2 speed w/AWD transfer case

Post by LiftedAWDAstro »

I found another site that gives individual repair parts for the different t-cases. From the part numbers listed, I should probably be looking for a NP236 t-case as many of the parts are the same as in the NP136.

Cobra Transmission NP236

Cobra transmission NP136

Image
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy

ihatemybike
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Re: Quest for another 2 speed w/AWD transfer case

Post by ihatemybike »

Think adding a switch to keep the solenoid activated would help in the meantime or do you think it would burn the solenoid out?
Aaron

2005 Astro (Gandalf) - AWD, 4.3L, 3.42, 130k+ miles
1997 Astro (Grumpy - $250 Rally Van) - AWD, 4.3L, 3.42, LSD, 2" lift, 31" tires, 335k+ orig engine, $30 eBay fuel pump
Prev Astros:99,97,00,94,87,86
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Re: Quest for another 2 speed w/AWD transfer case

Post by MountainManJoe »

I think it's a stepper motor, not a solenoid, and yes I think it would burn out. It would be like turning on your drill, and holding the bit so it couldn't turn.

Topic author
LiftedAWDAstro
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Re: Quest for another 2 speed w/AWD transfer case

Post by LiftedAWDAstro »

Found some TCCM info...

Reman'd TCCM's.

Looks like the TCCM is in the left kick panel. Gonna check tomorrow.

RPO codes: I am looking for NP8 code donors.

NP0 TRANSFER CASE ACTIVE, SINGLE SPEED, PUSH BUTTON CONTROL

NP1 Transfer case, Insta-Trac, electronic shift
NP1 Transfer case, electronic shift
NP1 Transfer Case, Electronic Shift, Two Speed
NP1 Transfer Case – (Electric) – Full Range
NP1 Transfer Case – (Electric) – Two Speed
NP1 Transfer Case Electric Shift Cont, Two Speed
NP1 TRANSFER CASE ELECTRIC SHIFT CONT, TWO SPEED

NP2 Transfer case, floor-mounted shifter
NP2 Transfer Case- (Manual) – Full Range
NP2 Transfer Case- (Manual) – Two Speed
NP2 Transfer Case Manual Shift Cont, Two Speed
NP2 TRANSFER CASE MANUAL SHIFT CONT, TWO SPEED

NP3 Transfer case, AWD electronic automatic system
NP3 Transfer Case – (AWD)
NP3 Transfer Case-All Wheel Drive (AWD)
NP3 Transfer Case All-Wheel Drive (AWD)
NP3 TRANSFER CASE ALL WHEEL DRIVE (AWD)

NP4 Transfer case, AWD active automatic system
NP4 Transfer case, electronic Autotrac
NP4 TRANSFER CASE ACTIVE, ALL WHEEL DRIVE (AWD)

NP8 Transfer case, electronic Autotrac
NP8 Transfer case, active, 2-speed
NP8 Transfer Case – (Active) – Push Button Control, 2 Speed
NP8 TRANSFER CASE ACTIVE, TWO SPEED, PUSH BUTTON CONTROL
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy

Topic author
LiftedAWDAstro
I have my van tatooed on my cheeks
Posts: 4379
Joined: Sat Sep 09, 2006 3:35 pm
Location: New Haven, NY

Re: Quest for another 2 speed w/AWD transfer case

Post by LiftedAWDAstro »

After hours of research and reading a thousand different forum posts, I have come to the conclusion I am pretty much going to stay away from an electric shift AWD transfer case. While it would be a cool experiment, I don't want to be trying to figure out programming and wiring of a TCCM and all 3 different speed sensors plus deal with the lack of reliability of the 226/236 or 246 autotrac transfer cases. There are more threads on guys swapping out these cases for regular manual shift ones than there are of guys swapping them in. You have to worry about the TCCM, one of the sensors, the clutch pack wearing out, the shift motor, and the special AutoTrac 2 GM only fluid!

Make sense so far....it does for me. then I remembered someone posting the following: :yawinkle:
photo_van wrote:***UPDATE*** So, last night, as the 70 mph winds were literally ripping the shingles off our roof (again), I had an epiphany :rolleyes: . A bit late for me, but if someone else is actually stupid enough to do this.

If you used an NP 241c as your donor, I bet you could use the entire front half of the 241. Input, planetary, front output and front case with the GM 6 bolt pattern! It looks identical to the 242 from photos.

The 241c would also have (I think) the VSS and reluctor. With some modification, you might even be able to swap the output bell housing from the 241. It is cast and machined for the VSS.

You would have to some how extend the casting around the shift rod as the 242’s is quite a bit longer.
And then I remembered I happen to have the correct GM 6 bolt adapter from a 1/2 ton truck and I also happen to have a complete (except for the rear case half) NP241C also from a 1/2 ton truck! Called my buddy Darrel (his wife is "hunterncruse" on here) and talked to him about the 241 and getting ahold of a 242J. He happened to say he knew of a broken 242J that could be used for mockup. He is getting the 242 tomorrow and already has the 241 at his place. He'll have them bolted together tomorrow afternoon probably! More to come on this swap! I will be using a cable to shift the case since I did that on the SPB and it worked great.
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy

photo_van
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Re: Quest for another 2 speed w/AWD transfer case

Post by photo_van »

Ya buddy, I was hoping someone would try this! I was down at the transmission shop the other day, a 241 was sitting on the ground; I was thinking, "wish I had one of those when I started my project!"

Just curious; is the 1/2 ton six bolt different then the adapter on your '05?

Also, we're supposed to get a 5' dump here so hopefully I'll get to try out the awd.
1998 AWD/4WD
4" lift, 31x10.50's, NP 242j/c hybrid, 4.10 gears, S10 front disconnect, rack & pinion steering, trans cooler, rock sliders, ARB fridge, house battery and 100w solar, swing out rear rack with foldout camp table, bed and passenger swivel chair
dirt bag camping rig
1981 Toyota 4x4 pu
1974 John Deere 710
User avatar

MountainManJoe
I have my van tatooed on my cheeks
Posts: 3088
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Location: The Pacific North Wet
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Re: Quest for another 2 speed w/AWD transfer case

Post by MountainManJoe »

In my research, I found these two website to be a goldmine for TC info.

http://www.rsgear.com/products/transfer-cases.aspx
http://www.transmissiondigest.com/tech.htm (no descriptions so you have to dig a little)

Topic author
LiftedAWDAstro
I have my van tatooed on my cheeks
Posts: 4379
Joined: Sat Sep 09, 2006 3:35 pm
Location: New Haven, NY

Re: Quest for another 2 speed w/AWD transfer case

Post by LiftedAWDAstro »

Went out after plowing snow and did a few quick measurements. The 136GM is 19" overall. The distance from the t-case face to front output is about 4-1/2". The 5 bolt adapter is about 3-15/16". The 6 bolt adapter from a 1/2 ton truck is just shy of 4-1/2" long.
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy
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