NP 246 transfer case

[computer monkey]

Does anyone know of any links for info on these cases. I have a service 4 wheel system light on....when I shift to 4 wheel and back the lights on the buttons blinks a couple of times them go back to 4hi. When I take the shift motor out of the circuit the front shift motor on the axle works fine. Plus I am having trouble finding the 4hi on the transfer case(manual shifing it). I do believe I have found 4lo, netural and 2 wheel positions. Any help is welcome. Thank you.

[DA BIG ONE]

Originally posted by computer monkey:
Does anyone know of any links for info on these cases. I have a service 4 wheel system light on....when I shift to 4 wheel and back the lights on the buttons blinks a couple of times them go back to 4hi. When I take the shift motor out of the circuit the front shift motor on the axle works fine. Plus I am having trouble finding the 4hi on the transfer case(manual shifing it). I do believe I have found 4lo, netural and 2 wheel positions. Any help is welcome. Thank you. There is no reliable info on the web....

The NP 246 autotrac always spins the front driveshaft unless in neutral, yes, even in 2wd. The clutchpack is always engaged and is spring loaded to buffer any strain that may occur in drivetrain.

When in 2wd only the front motor at the differential disengages letting the axels spin freely "when front wheels are off ground".

4wd hi, 4wd low, and neutral are only shifting points for that case.

Blinking lights are usually a bad switch, or the controller.

To bypass the auto 4wd feature which is intergrated into the ABS, use a PosiLoc to shift from 2wd to 4wd. The case can be shifted manually, but you would have to make your own shifter and slot floor for install.

Parts can be had from: http://www.drivetrain.com/transfercasesparts.html#New%20Process%20Model%2024 6

I have for a long time now have been compiling information on this unit from NP and their distributors. GM has bad information published in there owners, and repair manuals, even found Chilton's and others have bad info on it too!

[computer monkey]

4wd hi, 4wd low, and neutral are only shifting points for that case.

Thank you for you reply.....I have been trying to shift the case manually using a cresent wrench...I thouht I had found 4lo, neutral and 2hi. If I understand what you are saying then what I think is 2hi is actually 4hi and then something is wrong with the inside of the transfer case. When I have it in what I think is 2hi I can spend the front output shaft. Any thoughts. If the transfer case only shift in 4lo, neutral and 4hi where does it get 2hi?

[DA BIG ONE]

Originally posted by computer monkey:
4wd hi, 4wd low, and neutral are only shifting points for that case.

Thank you for you reply.....I have been trying to shift the case manually using a cresent wrench...I thouht I had found 4lo, neutral and 2hi. If I understand what you are saying then what I think is 2hi is actually 4hi and then something is wrong with the inside of the transfer case. When I have it in what I think is 2hi I can spend the front output shaft. Any thoughts. If the transfer case only shift in 4lo, neutral and 4hi where does it get 2hi? Read my earlier post again!

Your t-case is always turning the front shaft unless it is in neutral.

When Auto4wd (actually 4wd HI)is selected "the t-case controller is engaged", when slippage is detected via front driveshaft sensor/rear driveshaft speed sensor and the ABS then the controller engages the front differential actuator (4wd HI), when there is no slippage detected the controller disengages the actuator (still in 4wd HI but front axles are not engaged).

When in 4wd HI the front axles are engaged always.

When in 4wd LO the t-case is shifted to the low ratio, and the front differential actuator is engaged.

Your front diff is of the open type.

With the PosiLoc you can shift into 4wd low and not engage the front differential, this gives you 2wd low.

If I remember correctly neutral is dead center on the t-case, but I have to go into the garage and dig one out to confirm this.

If you have the larger 14 bolt IFS differential then ARB has an air locker for it, locked front diff is a plus in some situations. With this setup you have an on board compressor, you can get the ARB air hose and adapter then air up your tires off road, or even fix your own flats in a pinch.

[DA BIG ONE]

Originally posted by DA BIG ONE:
</font><blockquote>quote:</font><hr />Originally posted by computer monkey:
4wd hi, 4wd low, and neutral are only shifting points for that case.

Thank you for you reply.....I have been trying to shift the case manually using a cresent wrench...I thouht I had found 4lo, neutral and 2hi. If I understand what you are saying then what I think is 2hi is actually 4hi and then something is wrong with the inside of the transfer case. When I have it in what I think is 2hi I can spend the front output shaft. Any thoughts. If the transfer case only shift in 4lo, neutral and 4hi where does it get 2hi? Read my earlier post again!

Your t-case is always turning the front shaft unless it is in neutral.

When Auto4wd (actually 4wd HI)is selected "the t-case controller is engaged", when slippage is detected via front driveshaft sensor/rear driveshaft speed sensor and the ABS then the controller engages the front differential actuator (4wd HI), when there is no slippage detected the controller disengages the actuator (still in 4wd HI but front axles are not engaged).

When in 4wd HI the front axles are engaged always.

When in 4wd LO the t-case is shifted to the low ratio, and the front differential actuator engages axles.

Again, in 2wd the front axles only are disconnected!

Your front diff is of the open type.

With the PosiLoc you can shift into 4wd low and not engage the front differential, this gives you 2wd low.

If I remember correctly neutral is dead center on the t-case, but I have to go into the garage and dig one out to confirm this.

If you have the larger 14 bolt IFS differential then ARB has an air locker for it, locked front diff is a plus in some situations. With this setup you have an on board compressor, you can get the ARB air hose and adapter then air up your tires off road, or even fix your own flats in a pinch. </font>[/QUOTE]