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swap out NP 136 transfer for ...

4K views 25 replies 7 participants last post by  racrx7 
#1 ·
the transfer in my 2005 AWD astro has not worked in 2.5 years!! 2wd just fine, but the AWD never kicks in.
mechanic has swapped out every part in the system with another 2005 AWD astro and is convinced that it has the be the transfer case, not the actuator motor, the sensors or the control module (which was a bitch to get at to the left of the drivers foot zone).

so....rather than order an $800 rebuilt NP 136 i might consider a different transfer out of a jeep grand wagoner that has more options.
Like a low and a high range, AWD that kicks in automatically like the original transfer case, and a LOCKED in mode that keeps it in 4WD until i shift out of it. the mechanic has total confidence that he can successfully install it and bring a control cable up through the floor to allow me to be in control of the transfer case mode.

i definitely said "WOW" when i saw the center console out of the jeep with all its choices, low and high range and all that. would be great to have all those options, eh?

don't want to get into this and have it not work...

transfer case might be just $100 or so, plus cheap to install because i am down in mexico in southern baja. the 2 mechanics down here that i go to are both great, but like the mechanics in the states, they are not perfect. i think you'd be impressed how much they have helped me for free and not charged me when they put a lot more time and parts into repairs that did not come right the first time. one guy wrote off a thousand bucks when he could not get a repair perfectly completed. i followed up in the states and 2 shops up there charged me thousands and did not solve the problems they were working on. you can be sure they were never going to do anything for free...

any thoughts on this, my friends??

THANKS!!

lobo
 
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#4 ·
Open the hood. Pop off the cover of the fuse/relay center on the firewall on the driver's side, just left of the battery.

Turn over the cover. There is a diagram. Find the one labeled ATC.
 
#5 ·
Though if your mechanic has worked on it a few times and the fuse is the bad part, it's time to fire him.

As far as the TC swap, I say go for it, please document as much as you can.
 
#10 ·
I just completed a transfer case swap out. I built a hybrid NP236/246 case and installed it with all the electronics to make it a Select Trac like in the big Subrubans. All modes work as intended. A strait NP236 will bolt right in place of the 136 without any cutting or modding any shafts.

NP236/246 in the left, NP136 on the right. No external differences.
 
#13 ·
#15 ·
racrx7 said:
Do you plan on doing a writeup?
If there is interest in this, I can. I have some tidying up to do with the wiring to complete mine. ;)
Definitely!
 
#22 ·
Make sure you get all of the wiring from the transfer case forward, the TCCM WITH its connector and wiring intact, and same with the switch. You will graft the circuits needed from the doner vehicle to your transplant. You'll be ahead of the game :geek:
 
#25 ·
So, since you guys are using clutched transfer cases, I suppose you don't have to worry about changing the front axle to use the vacuum disconnect. I have a standard transfer case, and without the disconnect, I have to be more specific about how I use 4wd on my van. Made the mistake of running it down the highway on dry pavement in 4Hi, and then trying to shift into 2Hi on the fly. The extremely scary CLUNK CLUNK CLUNK was enough to stop me from having a 4wd van for the rest of the winter until I replaced the transfer case. Now that I know how to use it properly, it's great...but I still can't disengage 4wd easily...usually requires backing up or at least being in Neutral. I rarely use it anyway, but if I cared to, I'd end up in the yard pulling the front axle of an S 10 apart for the passenger side internals, along with the vacuum ball and switch.

I had considered upgrading to the clutched style transfer case ( 4 button ), but decided that it was more trouble than it was worth considering the lack of VSS input to the transfer case....I really didn't feel like adding the extra wiring to the van. :banana:
 
#26 ·
Made the mistake of running it down the highway on dry pavement in 4Hi, and then trying to shift into 2Hi on the fly
YIKES!! :shock: :shock: I'm no Rod Hall, but isn't true 4x4 on dry pavement a no no?

but decided that it was more trouble than it was worth considering the lack of VSS input to the transfer case....I really didn't feel like adding the extra wiring to the van.
.

What am I missing here? All the clutch transfer cases use the same three, shaft speed sensors. That was one part of the wiring I didn't have to alter. BUT, there was lots of other wiring to sort out lol





 
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