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goodwrench9124, ASE Certified Technician
Category: Chevy
Satisfied Customers: 3432
Experience:  Ase Master Certified, GM Master Certified Tech. Awarded GM Top performer, Hybrid certified
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I have a 1999 chevy astro van AWD and the front wheels do not

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I have a 1999 chevy astro van AWD and the front wheels do not pull ever.I replaced the transfer case encoder motor and that did not fix it.
Hello and welcome. have you had the system scanned for trouble codes yet?
Customer: replied 7 years ago.
I just bought it with 100,000 miles on it and never had anybody look at it yet.No trouble codes or anything
Ok, there are several electrical reasons why the front may not be pulling. there is also one mechanical reason why it may not being pulling. if it is a mechanical problem, usually a bad clutch inside of the transfer case. you really need to have the transfer case module scanned for codes first. this requires a high end scan tool. not just any engine code reader will work on this system. this will help lead to the problem
Customer: replied 7 years ago.
If it ends up to be an electrical problem or something minor and the transfer case is in good shape,is there any way possible to just bypass everything and maybe hook a switch to the encoder motor to engage the front wheels when I want,or any other way to manually engage the front wheels when I want?

not really. the clutch assembly is a special clutch.


The NV136 transfer case is an automatic transfer case with two drive ranges. Shifting from rear wheel drive to four wheel drive is done automatically when the transfer case shift control module receives wheel rotating slip information from the speed sensors. The transfer case shift control module then engages the transfer case motor/encoder to position the transfer case from rear to four wheel drive. When the transfer case shift control module receives information that the wheel rotation is the same on both axles, the transfer case shift control module sends position information to the motor/encoder to put the transfer case back into rear wheel drive. The 2HI position is for normal driving with the rear wheels pushing the vehicle. TheXXXXXposition is for driving through sand, snow, mud, gravel, or heavy rain at normal or slightly below normal speeds. The NV136 is manufactured at Syracuse New York by New Venture Gear a division of New Process Gear for General Motors.



Customer: replied 7 years ago.
Will a normal or "manual" transfer case just slip in place of the nv136 or would it be a major problem to swap?
not a 100 percent sure, but i am pretty sure that a NVG 241 manual shift transfer case will bolt up.
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