2002 yukon 4x4 will not engage

[nickh57]

Whats up Guys.
Im Nick, and new to the forum. I have a 2002 GMC Yukon i took on the beach today. Little did i know the 4x4 never engaged even though the indicator light was on next to the 4hi button. i took a closer look when i got back to the house and laying under the truck you can hear both the transfer case shift motor and differential actuator both making noise. If anyone has experienced the same issue or a similar one any help diagnosing my problem would be much appreciated. I really dont have the money to have a dealer take a look at it so please try and keep the coments telling me i really should have a dealer look at it off this thred. Thanks again in advance for any help. hope to get some info soon

 

[big_b_in_PA]

Get all 4 wheels off the ground, put the vehicle in 4 high. With the engine off and vehicle in neutral, get underneath and turn the front drive shaft by hand and see if there's any engagement with the front diff. i.e. One wheel turn with the drive shaft. If it does, make sure try putting it in park, and turning the shaft. If it still turns, you may have a bad transfer case. If it doesn't, first take your actuator out of the front diff and make sure it is actually working. If that works, then try manually engaging the front diff, use something to push the shift fork. After that if all that checks out, check the cv shafts and joints, check your front diff fluid for shavings or chunks of metal.

I'm sure there's other things to check, but that will get you started in the right direction.

Good luck