GMC Troubleshooting Questions? Ask a Mechanic for Answers
My name is ***** ***** I am a professional here at Just Answer. I noticed that your question had not received a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.
There is some slack that can be heard when all of the gear boxes are engaged like when in 4wd which may give off a clunk or slight slip feel when first taking off and can be normal as there has to be some slight slack in the gear boxes to keep them from binding up.If this is an actual slip feel to where the engine revs up but no or little movement from the vehicle occurs this can be an issue internal in the transfer case as some can have internal components that can wear and cause this here and this will need inspected further to be sure.
One way to find out for sure if this is normal is to ask the dealer if they have another like/similar model that you can operate to see if it acts the same.If it does then this is the normal operation of your vehicle.If it does not then the dealer would drive it and see this and then they can re diagnose your model to locate and repair this fault.
If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.Thanks Pete.