NP203 Theory

[Cabcorner]

          Riddle me this - Would I be able to flat tow a 70's chevy  unconverted full time 4x4 that has locking hubs and a twin sticked transfer case by unlocking the hubs, shifting the transmission and transfer case into neutral and then locking the diff in the transfer with the second stick ?

[Irish_Alley]

well i think one stick would be H or L. and the other stick would be your lock- unlock. so if you unlocked the hubs your good there then you just put the tcase in N your good there. but i have heard and seen a lift crane being towed. they just put it in N but the rear shaft still turned the transmission, but the pump wasnt turning so it burnt up the trans. thats not a cheap trans to replace

[Cabcorner]

                        Well I could put the tranny in park , the transfer in neutral ,unlock the hubs and lock the diff in the transfer case .

[Irish_Alley]

the thing they had to do with the lift crane was remove the drive shaft

[75gmck25]

The owner's manual for my '75 GMC K25 with NP203 says it can be flat-towed with the transfer case in neutral and the transmission in park. It does not mention any speed or distance limits.

Bruce

[scorpion]

The owner's manual for my '75 GMC K25 with NP203 says it can be flat-towed with the transfer case in neutral and the transmission in park. It does not mention any speed or distance limits.

Bruce

What are you attempting to do/solve?  The front diff wouldn't spin (lockouts allow free spin of the hub assembly) but the transmission would still be spinning because the rear end would be spinning the rear yolk on the tcase.  When flat towing the ideal setup would allow all drivetrain components to not rotate which would be accomplished with rear lockouts like warn made for jeeps for that specific reason.  Any drivetrain component that spins during flat towing realizes the miles as if driven itself (though less load).

[Irish_Alley]

if i understand the autos right your not lubricating the parts and manuals idk