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NP 246 Encoder Motor

Big T

Big T

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Location
Fullerton, CA
Looked all over and can't find the Encoder Motor for the NP 246 Transfer Case. Is this a dealer only part? Same thing, can't find the rear shaft seal. Is that dealer only?
 
I googled "Encoder Motor for the NP 256 Transfer Case" and got multiple hits on Amazon, Ebay, and other sites.
Amazon transfer case actuator with Encoder Motor
Monster Transmission and powertrain has refurbish kits for $90, Master Rebuild kit for $250 and complete cases for $1100.
I didn't see the Encoder Motor in the master rebuild kit.
Give Kevin a call at Gearz Transmission Service here in Lehi 801-768-8892. He'll give you straight answers to source parts best for you in California.
 
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Paveltolz said:
I googled "Encoder Motor for the NP 256 Transfer Case" and got multiple hits on Amazon, Ebay, and other sites.
Amazon transfer case actuator with Encoder Motor
Monster Transmission and powertrain has refurbish kits for $90, Master Rebuild kit for $250 and complete cases for $1100.
I didn't see the Encoder Motor in the master rebuild kit.
Give Kevin a call at Gearz Transmission Service here in Lehi 801-768-8892. He'll give you straight answers to source parts best for you in California.
Click to expand...
I seen in the Amazon page where there is a $25.00 rebate from Delco if the old unit is sent to them, that has got to be a nice bonus.
 
As an Amazon Associate we earn from qualifying purchases.
Paveltolz said:
I googled "Encoder Motor for the NP 256 Transfer Case" and got multiple hits on Amazon, Ebay, and other sites.
Amazon transfer case actuator with Encoder Motor
Monster Transmission and powertrain has refurbish kits for $90, Master Rebuild kit for $250 and complete cases for $1100.
I didn't see the Encoder Motor in the master rebuild kit.
Give Kevin a call at Gearz Transmission Service here in Lehi 801-768-8892. He'll give you straight answers to source parts best for you in California.
Click to expand...

It’s a NP 246.

I met up today with Will L. and had him test drive the truck. We pretty much both concluded that it’s stuck in 4Hi, despite the button showing 2Hi. We shifted it into 4HI on dry payement and the effect was the same.

I saw reman NP 246 transfer cases for $1K. If that includes encoder motor, then that’s probably the route I go. Just way less work and down time.
 
As an Amazon Associate we earn from qualifying purchases.
Big T said:
It’s a NP 246.

I met up today with Will L. and had him test drive the truck. We pretty much both concluded that it’s stuck in 4Hi, despite the button showing 2Hi. We shifted it into 4HI on dry payement and the effect was the same.

I saw reman NP 246 transfer cases for $1K. If that includes encoder motor, then that’s probably the route I go. Just way less work and down time.
Click to expand...
Crawl underneath it and see if you can rotate the front driveshaft. If you can it's not in 4x4. And the encoder motor is a 5 minute job. Encoders usually are not included because the cases were the same for the most part from 96 on, but theres several encoders.
 
I tried to rotate the driveshaft and could not. That was while it was in park, if that matters.
 
MrMarty51 said:
I seen in the Amazon page where there is a $25.00 rebate from Delco if the old unit is sent to them, that has got to be a nice bonus.
Click to expand...

I checked that page and those encoder motors are for the NP 241/243 which were the prior models.

The master rebuild kit did not include the chain.

I did check the Monster Powertrain and powertrain site. They sell the full reman for $1,049 with free shipping. Core charge is $350 and they offer a flat rate core pickup of $95. Add a shift motor for $125. I'm going to call them next week to make sure on the shift motor.
 
Supposedly there's an aluminum tag on the transfer case which identifies the model. I could not find the tag.
 
Big T said:
It’s a NP 246.

I met up today with Will L. and had him test drive the truck. We pretty much both concluded that it’s stuck in 4Hi, despite the button showing 2Hi. We shifted it into 4HI on dry payement and the effect was the same.

I saw reman NP 246 transfer cases for $1K. If that includes encoder motor, then that’s probably the route I go. Just way less work and down time.
Click to expand...

Is this a 3 Mile Island control system? :confused: Wait, What? 3 Mile island's reactor melted down because a TP valve in the cooling system stuck open and the idiot light (and switch) in the control room indicated it was "commanded" closed while the valve itself was wide open.

So does the Button showing 2 HI indicate "commanded" mode or does it indicate that something actually happened? And if so does it indicate that the front axle shifted out or the transfer case motor actually moved?

To be stuck in 4x4 would need both the front axle locked in and transfer case stuck in 4x4. I know you feel the front axle locked in even if the transfer case is in 2 High. I doubt with the front axle 'unlocked' you would notice the transfer case stuck in 4x4.

Sure shift forks fail in the transfer case, but, to have both the transfer case and front axle locked in 4x4 has me suspect the control system. I am not clear myself how the push button works in regards to my question.

Maybe @Will L. can explain how you guys arrived at a bad transfer case?
 
I wouldn't jump to bad transfer case. Yes the control lights are functioning like normal. Even blinking when you first select it until the truck moves a couple inches to engage in some cases and instant on in the other. It was a short test drive and determined regardless of the button selection, the front axle is binding against the drive of the rear axle in tight corners. Does the lights only get feed back from transfer case, front axle, or both?

The best coarse of action imo is to get it up on 4 jack stands, remove front drive shaft. Then test if transfer case is operating properly. Then test if front axle is operating properly. It has been so long since having to repair one these 4wd units, that I can't remember proper procedures or any common errors other than those lock up units on the front axle being crappy in the cold and loving the idea of a cable operated one. Thinking about it, @THEFERMANATOR 's call on free rotating driveshaft should prove no 4x4 of transfer case, but if front axle is goofed, couldn't that cause an issue of shaft not spinning due to front axle locked in or hanging up? iirc he said this all started after the brake conversion to the gmt800 style.

Also I recall an occasional sound when turning tight on the pavement that was similar to dust shield rubbing rotor-
Both @Big T and I thought that was the sound. Possibly something else in there hanging up? It was on the drivers side when turning left. Was not tire rub.

Definitely don't start buying parts until bad components are verified by disassembly/ inspection.

Also, only front shocks were bad, your rears were ok. Pleas turn that left front tire into a swing for the grandkids asap- haha
 
The lights in the switch are triggerred via the tccm, and receives the oosition data from the encoder motor position. Jack the front wheels up off the ground and see if it's the actuator or transfer case locked in. Actuators rarely fail in the front, and if it displays 2wd, the tccm shouldn't be grounding the front axle actuator to engage it. It's easy enough to test the transfer case, take 2 minutes and pop the encoder motor off, takea crescent wrench, and see if the transfer case shifts manually. I don't think the 246 uses detents, so you can't leave the encoder off and drive it.
 
THEFERMANATOR said:
The lights in the switch are triggerred via the tccm, and receives the oosition data from the encoder motor position. Jack the front wheels up off the ground and see if it's the actuator or transfer case locked in. Actuators rarely fail in the front, and if it displays 2wd, the tccm shouldn't be grounding the front axle actuator to engage it. It's easy enough to test the transfer case, take 2 minutes and pop the encoder motor off, takea crescent wrench, and see if the transfer case shifts manually. I don't think the 246 uses detents, so you can't leave the encoder off and drive it.
Click to expand...

I did the test where I put the front end on jack stands and spun the wheels. The front drive shaft spun with them.

I will put front and back on stands and see what spins when in gear.

I don’t know what a tccm is.

4 Lo does not work and has not for years.
 
Look and see if there is a black plastic motor screwed into the passenger side axle tube right beside the aluminum diff housing with a plug in it. Sometimes people remove them and install the aluminum plug that keeps the front axle locked in. If jacking a front tire up and turning it makes the driveshaft spin, then the transfer case is not engaged, only the front axle.
 
Alright, put it up on stands and had my wife fired it up, put in drive, 2Hi and all wheels spin. Shut it off and got underneath. Put it in neutral and shifted to 4Hi and nothing at the front actuator, but I can hear the encoder motor shifting. Unplugged the actuator and put the plug back on and still nothing. Checked the 4wd fuse and it's good. Is there some testing I can do with a test light at the plug? When I installed it, I tapped into the harness back of the FFM to the brown wire coming from the sender on the transfer case. Could be with all the manifold removals and installs I did when replacing the IP, that I messed up the splice there. If it tests fine at the plug, then I need a new actuator.
 
Here's the test up on the stands.....


The clunk is from the lug nuts being on loose, as I was also rotating tires.

Will L.: I put that worn one in the back. Two or more trips to Big Bear and it's done and on with the next one.
 
Will L. said:
I wouldn't jump to bad transfer case. Yes the control lights are functioning like normal. Even blinking when you first select it until the truck moves a couple inches to engage in some cases and instant on in the other. It was a short test drive and determined regardless of the button selection, the front axle is binding against the drive of the rear axle in tight corners. Does the lights only get feed back from transfer case, front axle, or both?

The best coarse of action imo is to get it up on 4 jack stands, remove front drive shaft. Then test if transfer case is operating properly. Then test if front axle is operating properly. It has been so long since having to repair one these 4wd units, that I can't remember proper procedures or any common errors other than those lock up units on the front axle being crappy in the cold and loving the idea of a cable operated one. Thinking about it, @THEFERMANATOR 's call on free rotating driveshaft should prove no 4x4 of transfer case, but if front axle is goofed, couldn't that cause an issue of shaft not spinning due to front axle locked in or hanging up? iirc he said this all started after the brake conversion to the gmt800 style.

Also I recall an occasional sound when turning tight on the pavement that was similar to dust shield rubbing rotor-
Both @Big T and I thought that was the sound. Possibly something else in there hanging up? It was on the drivers side when turning left. Was not tire rub.

Definitely don't start buying parts until bad components are verified by disassembly/ inspection.

Also, only front shocks were bad, your rears were ok. Pleas turn that left front tire into a swing for the grandkids asap- haha
Click to expand...

Will, found the rub problem. I noticed the inside lip of the rim was shiny. The wire harness for the ABS was rubbing on left turns at the limit. I adjusted the harness in the mounts and added a zip tie to further secure it out of the way.
 
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