i have a 01 SCREW with the 5.4 i put it in 4 low and the truck wouldn't move put it back to 4 high and then turned it off and still nothing if i put it in park it grind's so when i went to tow it i was on a slight hill put it in park and it rolled. WTF?

 

Manual or electric shift on the fly? When you shifted into Lo did the low indicator in the instrument cluster illuminate? Did the Lo indioator go out in 4Hi?

If the 4Lo indicator never illuminated you most likely never made it fully into 4Lo. When you shifted back into 4hi the same problem might have kept the t-case from going back to 4hi. The T-case would have been in some sort of neutral. That would explain the truck rolling. The grinding going into park would have been the tranny still spinning when the park pawl is ingaged. Because with the t-case in neutral the tranny is not connected to the rear wheels so your foot on the brake would not hold the tranny outputshaft from turning. Outputshaft turning while shifting into park is like shifting into park with the truck still rolling.

Ok, now down to the repair. Test the electric shift motor in the t-case and repair/replace it.

JMC

 

Thank you! it is electric shift, and yes the low indicator light came on and then went out when it was switched out of 4 low. is the electric shift motor inside the t-case or outside and is their a way to do a quick fix to get it home?

 

1- Tap it like you would a starter to try and get it to shift.
2- Unplug connectors and clean then and reconnect.
3- Pull it off and shift the t-case manually.

JMC

 

A word of caution if it engages 4x4 but will not go into 2Hhi do not drive it like this. Either disconnect the front drive shaft or disconnect the center axle disconnect vacuum hose at the 4x4 solenoid. It is the one closest to the passenger fender. Apply vacuum to the other one and reconnect it leaving the left hand one disconnected. This will keep the front axle disengaged and not allow the drive line to bind while driving on the road.

JMC

 

Forgot to answer your question about motor. It is external at the rear of the t-case. It looks like a wiper motor.

JMC

 

THANK YOU!!!!

 

well i did the tap made sure conectors were clean and pulled it off to switch in manual and the pointer was in the 2 high location. i did move it and was able to get the truck to move but it felt like it was in 4 low was going like 10mph and the speedo said i was going 60mph then it popped back into that "neutral" position?? but the pointer was still @ the 2 high location.

 

To get the transfer cse to shift into 2Hi from 4Lo you have to be under 5mph tranny in neutral and foot on the brake. Once this is done the t-case will shift and the GEM will indicate the change by turning off the Lo and 4x4 indicator lights. What tells the GEM to turn off the indecator is the contacts in the t-case shift motor housing. Obviously the contacts are moving becasue the GEM is turning off the indicators. The T-case itself not actually shifting would indicate a faulty Motor or internal shift linkage. To diagnose this you will need to remove the motor and shift the linkage by hand. When you remove the motor you will see how the shaft turns to rotate the linkage to complete the shift. If the linkage moves by hand the odds are that the motor is deffective. I don't mean thet you could turn the linkage with your hands, use vice grips. FYIW these electric motors are known to go bad.

JMC

 

i did pull the shift motor off. and put it in the 2hi location but the truck felt like it was in 4low and the speedo was reading 60mph but was only going arround 20 then it popped back into neautral. when i shift in by hand on the TC does the shifter in the truck have to be in "p" or "n" ? thanks again!

 

For the t-case to actually shift the tranny need not be in park or neutral. You need to switch the dial for the GEm to command the front axle to disconnect. This will not happen if the tranny is not in N or P and the Brake pedal depressed. One more thing, the linkage is free to move if the motor is not holding it in place.

JMC

 

ok. well i got a new shift motor for the TC put it on and i get nothing! i put it in 4hi and it lit up on the dash tried 4lo but it did not lit up?? so i towed it home, i was almost home and it started to grind on and off like it did when i would put it in park???????????????????????????????

 

How did you tow it home? All 4 wheels off the ground? Obviously not if there was grinding involved. With the motor out of the t-case turn the lever and watch for the motor to move. Does it move back and forth between the 3 positions? Do the lights turn on and off correctly?

JMC

 

ok i just pulled it off, had my daughter switch it and it moved from 2hi to 4hi but when switched to 4lo and back to 4hi it did NOT move????

 

Remember the truck must in neutral and brake depressed for it to shift into 4lo.

JMC