13 tundra 5.7 4x4

My neighbor has an 2013 5.7 tundra 4x4. He says that while in 4 wheel drive it made a loud popping sound. He says the it used to turn off road fairly smoothly but now acts like the front is not spinning the same speed while turning. ( basically it does not act the same as before) ok. I drove it and the 4x4 hi and lo acts perfect while driving straight. I cannot hear anything that is out of ordinary. But at lower speeds even in gravel, while turning. it feels like it is really fighting itself to even make a small turn. You have to give it gas and it will spin either one front tire or one back tire. Actually feels like it's in a low gear in front and high in back. Or like the brakes are engaged in front. No codes and other then the differential leaking out of the rear mount bracket I see nothing wrong. Front axles don't click on tight turn so cv should be good. Any suggestions on what to check would be appreciated. I know the fluid level needs checked/ filled. Thanks for help

 

I’m not sure what you are calling the “rear mount bracket”. Or how the differential can leak from a bracket. This sounds like a transfer case or front diff problem, but would need further diagnosis.

 

I thought it was normal for it to be tough to turn while in 4wheel drive.

 

Welcome from TX new guy.

Bad hubs maybe?

 

Is the transfer case locked?