as some of you guys know my 4wd has not been working since early february,
ok so this has been a ongoing problem that Ive been ignoring, now that spring is here its a good time for some offroading, so since the first of february my truck in the sig wont go into 4wd. Ill hit the 4hi button (autotrac case) and i can hear the transfer case try and shift but it wont complete( the button blinks from 2wd to 4hi for a couple seconds then back to 2wd) I keep trying and it wont work, eventually the lights turn off and the service 4wd light pops on, But if I only try the button once or twice the service 4wd wont come on.I also removed my actuator and had it in my hand while my dad pushed the 4hi button, the plunger on the actuator came out then went right back inside, so anyone have any ideas? my dash switch doesnt seem to be the problem...

 

I dunno if its the same but that same thing was happening to my roomates blazer you could hear the accuator try to work but it never would go into 4wd. We switched out the acuator and it fixed the problum.

 

i might try replaceing mine and see what happens, cause my actuator plunger does move, but it comes out then right back in

so his 4wd light just blinked then went back to 2hi?

 

yes and the service 4wd light would come on. you could try to manally pull the cable that the accuator is supposed to pull and see if it goes in 4wd

 

have you ever had your tranny worked on before?

 

I'm telling you bro, that it's the Encoder Motor...part # 12474401. In the newer models (03 and up) you can buy just the encoder motor sensor, but in your model you have to have the encoder. GM has a technical bulletin out about this...here's the TSB # 99-04-21-002. I've seen this a thousand times.

PM me and I'll send you the Technical Service Bulletin that explains this.

Hope this helps.

 

Lol lets say I was in denial, cause its such an exspensive part, but Im ready to bite the bullet, stopped at the best transmission place in town, and the owner told me right off that he almost gurantees its the encoder motor, damn 700 dollar parts....