I noticed this the other day, and IDK if I should be concerned or not, but as I was backing out of my driveway I noticed as I gave the truck some gas, the four-wheel drive lever moved as if the transfer case was under load or engaged, even though it was not. I drove slowly down the street and gave it some gas and watched it move again. I'm just concerned something is not disengaging along the four-wheel drive system and will cause a problem. I also noticed I've got ATF leaking from the rear output seal of the transfer case. Are these things indicative of a major issue?

 

Shifter moving side to side as engine load changes? Fairly normal for some movement, as it is mounted to the trans/t-case. If the movement seems excessive, check the engine and trans mounts. If they are worn/broken/loose, they can allow excess movement.

 

lever moving is normal. The leak can be fixed with a new seal. Check the ujoints while the shaft is out.

 

The lever moves forwards and backwards. Not sure if it matters.

I've got a pretty loud metallic clunk from the shaft when going between Drive and Reverse so I bet I need U-joints anyway.

 

Check the rear mount. I may have separated.

 

How much does it move? They all do it to some extent. And if you hear a clanking, I'd would check the ujoints, that could explain why the seal is leaking.

 

Rear mount of what? Transfer case?

 

Yea Tranny or TC. Theres only one back there.