ADSMITH

I have a 2000 Silverado LT Z71 with push button 4wd. When I press the 4wd hi button you can hear the transfer case engage but no 4wd...it will go into low range but is still no power on the front wheels. Pulled the actuator out today and it goes in and out as I guess it should. but I can push it back in without applying much force. Also is there supposed to be a 4wd light on these truck other that the little lights on the buttons....HELP PLEASE!!!

ToooTall1

When you engage 4Hi or 4 Lo check to see if front drive line is not movable when stopped. If it is the transfer case is not switching when 4HI/Lo is button is pushed the drive line will move when turned by hand. Did you check to see if the actuator is actually working, a shaft will come out with the actuator having powered applied. It engages the axles to the carrier in the front differental. Also their is no 4x4 light on dash, the buttons tell you what position your in when their lit. Also the oil used in the Transfer case is called Auto-Trac II by GM,Blue in color. The front differental takes 75-90w regular or synthetic gear oil.

ADSMITH

i have pulled the actuator out and pressed the 4wd button ...it comes out but I can press it back in with my left thumb and i am not left handed at all. the front drive shaft it turning when it is in 4wd and doesnt when its in 2wd...how much pressure should the actuator be putting out?

ToooTall1

When the 4hi/lo button is pushed the actuator pushes a rod that moves a set of forks that move a coupler to engage the axle to the carrier. The actuator holds the rod in when ever it has power. So it must be strong enough to keep engaged, As for the tx case when in 4hi/lo you are putting power from then engine to both front and rear differentials. If engaged properly the drive shaft should not turn when stopped as the you are basically lock up until you start driving. In other word front drive shaft is like the rear when stopped, it won't move. You must have power on when keeping the front drive engaged. I would replace the actuator first and move to the tx case shift motor. I have 3 4x4's 2 electronic and one manual. Have just recently replaced front diff on my white 1500, it just ate itself up. Also have replaced tx case motor, actuator and a module behind the dash. I'll do what I can to help you as I probably been there when it come to 4x4 or other 1999 to 2001 Silverados problems.

ADSMITH

when I hit the 4wd low or high button i cannot turn the front drive shaft even with a large screw driver threw the u joint. the actuator is coming out but like i said doent seem to be putting much force. could i jack up the front of the truck and take the actuator out, push it in with my finger, then if someone spins the front wheels it should turn the front drive shaft??? if that works then the actuator just isnt applying enough force correct?

ToooTall1

Yes you can remove the actuator and push in where you took the actuator out from with a screwdriver and have someone try to turn the wheel, that would lock front differential to drive shaft. With power off the front wheels will turn in opposite directions. First I would jack up front end and have power on and engage 4hi and see if the drive shaft turns while trying to spinning wheels. You should not be able to turn the wheels. Again must have ignition switch on, engine off 4hi/lo selected. If it is not engaging then your problem is with the actuator as long as it is getting power. 4lo normally can only be selected with power on, engine off, in neutral and foot on brake.

rjchevy

I'm also having similar issues with my 04 silverado. Mine will go as far as going into 4lo, but I can only keep it at idle speed. as soon as I try to give it some gas, it slips out of 4lo. I dont get any response in 4hi. I'd appreciate some insight too please

ToooTall1

For rjchevy it sounds like the transfer case is not properly engaging in the gear selected, could be transfer case motor or possible the transfer case module. See if you can hear the motor shift with engine off but ignition switch to on. Push 4hi and hear if the motor shifts and the light in switch stays lit. 4lo normally can only be selected in neutral, switch on and foot on brake. Check your fluid level in tx case. Electronic shift take Auto-Trac II and manual shift regular tx fluid. The light in switch should stay steady when gear is selected.

ADSMITH

What would be the symptoms if the transfer case fluid needs to be changed.? Checked it last night and it is black and looks thin?

ADSMITH

I jacked the truck up today all for wheels spin in 4wd low and high. But I jammed a block under both fronts and the rear kept turning and front completely stopped. Hit the gas and the front wheels wouldn't try. Think the wrong fluid in transfer case could cause this or do I have serious problems with the case itself?? There was no noise coming from the transfer case in 4wd lo or high indicating that sonething was broken