Damn Push-Button 4wd...urgh

[AllensHoe]

Hey fellas, (and maybe ladies...idk) I got a 96 Tahoe sport model with the infamous push button 4wd. I need help PLEASE. I replaced the actuator already with a new one. Checked for power and ground on both terminals down on the axle. Let the actuator hang in air while plugged in and hit the 4wd drive buttons while hanging out the door and looking under the truck to see if the actuator plunger moved out and that's where I've stopped. It never protruded like it was suppose to. Besides the terminals on the front axle idk what to check so I need yalls help there. It clunks and changes the transfer into 4lo but never engages the front axle. Just the rear axle..

Please please please help me...lol

 

[xanatost]

if your front axle is not engaging then that would be a transfer case problem. How do you know the front is not engaging?

Mods please move this to Engine and Drive-train

 

[AllensHoe]

Hey Xanatost. I've tried locking the 4wd in and power braked it. Only the rear wheels spun. Also the 4hi and 4lo lights just blink...and keep blinking as long as I don't push the 2hi button to disengage. My front actuator doesn't extend when I have had it plugged in and hanging out of the front axle after pushing either 4hi or 4lo. With a simple test light I've checked for power and ground on bother electrical clips on the front axle and they passed.

To move the thread to the drive train forum, is there a short cut or do I have to repost the whole topic and info? I'm a Newb and not all that bit of an expert when it comes to computer threads and forums. Thank you for the help.

 

[AllensHoe]

Push-Button 4wd not engaging front axle

Hey everyone. I've got a Tahoe finally after wanting one for YEARS now. Its a 2door Sport model, 96 and red...I traded a fourwheeler for it and when I got it, it needed a good detailing, water pump, and idler pulley. It has 212,000 miles but runs like a champ and I'm falling in love

But like any other push button 4wd drive system, I'm having issues with it engaging the front axle. The transfer case locks in 4lo cause I can feel it in the rear axle when I power brake it but no front axle engagement.

I've replaced the actuator with a new one. Checked the sensor terminals on the front axle for power and ground and they passed. BUT when I unscrewed the actuator, plugged it up, let it hang out the axle, and hit either 4wd button it never extended, At all. I used to have a z71 Chevy pickup but it had the manual shifter for 4wd so I don't know all the sensors to check for this one.

Help is greatly appreciated and thank you for having a place for us enthusiast to.go to and discuss our problems and find solutions.

 

[xanatost]

the blinking in the 4x4 sounds like there ould be a problem in the computer. Can you get the computer scaned and see if there are any codes?

 

[xanatost]

Sounds like a bad actuator. It is a common problem with the push buttons. I would go to a pull it yard and get a few of them for pertty cheep.

 

[AllensHoe]

Thanks for getn with me. I checked the remand actuator from Napa and couldn't get the 400ohms that I was suppose to when checking across the terminals for the actuator. I also rechecked the terminal ends that plug into the actuator from the Tahoe and had ground but no power...just from simple electrical I figured if it doesn't have power in it may be in the dash switches or that tccm on the column. Id like to check them before throwing $$$ away tho, just don't know how.

 

[AllensHoe]

We have a scanner at the shop that will test anything from engine, chassis, and transmission that I put on it and the only code was for a Mis-correlation between the came and crank sensors.

 

[xanatost]

That cool. Yea change out the switch. If you do the pull yard then get a few of them. Never know it one of them are bad as well and if you have any extra good switchs you can all sell them and recoup so money back. Now when you say the 4x4 switch is blinking is it in a pattern or just random? Mine sometimes come on but 9 times out of 10 it doesn't but I hear the transfer case ingageing and its in 4x4. There is a write up on here somewhere that tells you how to fix the switch but until input the lift on my hoe I'm not to worried about it.

 

[AllensHoe]

the closest junkyard round here is an hour and a half away so it may take awhile to get the switches. to answer your question bout the lights on the switches...the only time they blink is when i push the 4hi or 4lo button. then the button i choose to hit is the only light that blinks. i heard the constant blinking is the switch telling you its a partial engagement and not fully locked in.

i did however check the front driveshaft after locking the transfer case in and it wont freespin so that tells me the transfer case is operating correctly. then i took the actuator out and took a 6" socket extension and push it into where the actuator goes and it engaged the front axle to where the driveshaft wouldnt freespin in 2hi.

so my transfer works...my front axle engages when done manually...so its in the switches, tccm, or wiring. a continuity check is in order monday when i get back to the shop.

if you find that thread about how to check the switches just send me a PM or reply. thanks again. i will find this out...and post results for future people with the same occurences.