4WD to AWD Swap

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drdave81

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I want to use what I have in the truck currently to mimic the front axle from the Denali/Escalade

Until I swap an AWD front axle in, I want to have this axle permanently locked in 4x4. This will make it function just like the front axle from a Denali/Escalade. I would just swap one in, but all of those have 3.73 gears, where as I have 3.42. Down the line, this can be done, but not right now.
I found there are a couple options to do this:
1. Keep a constant 12V supplied to the actuator
2. Remove the actuator, then use something (people have used a socket, dowel, PVC pipe) to manually press the shift fork for the actuator in to place to keep the axle locked. Reinstall the actuator, but no electrical connection to it. This will basically serve as a functioning actuator, to keep the shift fork and collar slid into place, keeping the front axle locked.
 

Mudsport96

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I want to use what I have in the truck currently to mimic the front axle from the Denali/Escalade

Until I swap an AWD front axle in, I want to have this axle permanently locked in 4x4. This will make it function just like the front axle from a Denali/Escalade. I would just swap one in, but all of those have 3.73 gears, where as I have 3.42. Down the line, this can be done, but not right now.
I found there are a couple options to do this:
1. Keep a constant 12V supplied to the actuator
2. Remove the actuator, then use something (people have used a socket, dowel, PVC pipe) to manually press the shift fork for the actuator in to place to keep the axle locked. Reinstall the actuator, but no electrical connection to it. This will basically serve as a functioning actuator, to keep the shift fork and collar slid into place, keeping the front axle locked.
I think what was throwing him off *** your original engage 4hi and disconnect everything post. I knew where you were going, but I have done "similar" kinds of things in the past.
 
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drdave81

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I saw that too, I'm sure I can make something for far less than $100 lol. That's insane
 
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drdave81

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I finally got the truck back home today to play around a bit. I pressed the 4hi button, heard the front axle actuator engage and confirmed the front axle is locked in. I then disconnected the actuator wire harness and it stayed engaged (seems it does not require a constant 12V to stay actuated). So I removed the front driveshaft and drove around the neighborhood to make sure it wouldn't pop back out, so far so good. I'll drive around a bit more, but if it stays, I can go ahead and swap the NP149 case in and have AWD. Eventually I'll swap to a 1 piece front axle, but for now this will get me by.
 
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89Suburban

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I finally got the truck back home today to play around a bit. I pressed the 4hi button, heard the front axle actuator engage and confirmed the front axle is locked in. I then disconnected the actuator wire harness and it stayed engaged (seems it does not require a constant 12V to stay actuated). So I removed the front driveshaft and drove around the neighborhood to make sure it wouldn't pop back out, so far so good. I'll drive around a bit more, but if it stays, I can go ahead and swap the NP149 case in and have AWD. Eventually I'll swap to a 1 piece front axle, but for now this will get me by.


It must be a motorized actuator and not a thermal. Are you getting any service 4WD codes?
 
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drdave81

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Yes, its motorized. The thermal was the old style. There is the "Service 4wd" message on the cluster, but once the module behind the switch on the dash is unplugged, that will go away.
 

89Suburban

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Yes, its motorized. The thermal was the old style. There is the "Service 4wd" message on the cluster, but once the module behind the switch on the dash is unplugged, that will go away.
REEEEAAALY??? Interesting! Doesn’t the computer do a self check on the 4WD electrical system at startup? My dash switch lights up and blinks like it does. I know I am on the next gen platform but I still like to follow your trek here.
 
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drdave81

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It would do a check, but if the transfer case control module is unhooked, there's nothing to do the check. There may be some kind of a loss of comm in another module somewhere, but that wouldn't throw a dash light on the old stuff for loss of comm.
 
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drdave81

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Got the 246 pulled out, installed the 149. I'll have to post pics later on, but the 149 is about an inch shorter than the 246. So the rear driveshaft sticks out a bit more than it did, which will actually work out, since eventually this will get lowered. Now the kicker......... I need the driveshaft from a Denali/Escalade as my front one is about an inch too long now. It will not quite fit. I'll have to take a trip to the junkyard to get one.

Fun lil note that I kind of forgot about, since I had to leave the front driveshaft out, i just backed out of my garage into the driveway, my driveway has about a 10 degree angle to it. Without that front axle connected....... I don't have park lol. Good thing my park brake works haha!!
 

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