So, i recently re-ran the vacuum lines to the 4x4 actuator to transfer case and engine vacuum to transfer case. And i removed the encoder motor to test the transfer case. I shifted it thru all 3 functions with a 9/16 wrench and the actuator has vacuum in 4hi and 4lo, none in 2hi like it should. Got a new encoder motor and it will shift to 4hi and in between 4hi and 4lo all day long but wont shift back to 2hi. To be more specific it does shift to 2hi but goes right back, i can hear the clunk when it changes and vacuum to the front actuator fluctuates with the clunk. It will do this twice and give up and revert to 4hi. Only way I can return to 2hi is wait to hear it shift to 2hi and before it goes back pull the TCCM fuse. It will stay there, no light on, front drive shaft free, untill I go into 4x4 again. Was wondering if anyone had access to something that described the function of the system, something is telling it to not stay in 2hi and go back to 4hi. The encoder motor does make the shift fine but goes back, does the shift twice till it gives up. Any help is apriciated, Since the front shafts turns freely i think it's safe to assume the front axle disengages right?

 

have you tried to pull the tccm fuse for 30 minutes for a tccm relearn? Just a shot in the dark.

 

Yes. Did it when i installed the new motor. And ive tried it again. Had to use the 4x4 to pull my grandpa's truck and once again it works perfect but i have to trick it to get it back to 2wd. I wait to gear the shift then pull the TCCM fuse so it stops.

 

did you move the gear inside the encoder motor. if you did you might have damaged it. like if you had the transfer case in 4hi but the encoder motor was in 2hi. and you turned the gear in motor to match the transfercase. that would damage it.

 

No, i didnt move the new one's position. It came in the 2hi position. I have been shifting the transfer case with a 9/16 wrench so i put it in 2hi with that. I think im going to put a switch in line with the power from the fuse so i can "trick" the system easier. I've already established im going to make linkage and rig a floor shifter if it gails again. So far it works great other than going back to 2hi.

 

the encoder motor itself might be bad. you could of got a bad one. take it back and get a different one. these arent made new. they are referbished

 

If i find the reciept I may do that. However i broke the fins on it that go to where the plug is for easier instillation. That's how i got it off without pulling the front yoke off the transfer case. Figured they arnt nessesary but might have voided any warrenty...

 

yea thats exactly how i got mine in and out. what a pita. hopefully they will take it back. just put it in the box in its wrap. and just tell them you want a replacement. dont tell them you snipped the plastic off unless they ask you then be honest. also if you got it from like say autozone then they should have it in the computer with your name and phone number for warrenty. oh and make sure your rolling a bit when you put it back into 2hi. if you dont it binds things up and makes it harder for the motor to work.

 

It was a reman unit with a core charge and my place takes the box with the core charge. I have been busy replacing the head gasket on my Yota so the Jimmy got put on the backburner. I may just leave it like it is, I live in the south and dont use 4x4 often. It's not a big deal to me. Who knows, if i get bored I may try to take it off and attempt to swap it.