I recently bought a 2008 Silverado 1500 and when we switch it into 4 low we hear a really loud clunk noise (which i heard is common so i'm not too worried about that) but then when we try to drive it, it almost feels like the back tires aren't moving at all, and the RPMs go through the roof. Just wondering what this could be?

 

Have you brought this to the attention of your local dealer? I can also look into this with your VIN. Please feel free to contact me via private message. Thank you in advance.

Tricia, GM Customer Service.

 

4 low is low. That noise is probably the solenoid engaging, what about 4 hi?

 

4 hi works just fine. we can hear it switch over but that's all we hear and it's smooth when we drive. In 4 low, it jerks, like its struggling to move

 

Sounds like adjustment on the transfer case, take it to a 4 wheel drive shop

 

On the auto transfer (push button) models the book says shift transmission into nuetral and be under 3mph (if memory serves me), to go into 4 low. Try shifting it while stopped and in nuetral and see if you hear the clunk. If I try mine while moving I get a metallic clang, and the faster it is moving the the louder the clang. If I stop and shift into low it is quiet.

In low the RPMs will be up and the transmission will go through the gears quickly. Engine braking will also be more pronounced. That might be why it seems jerky if you aren't used to it, small modulations in accelerator position have big results in movement because of the the extra torgue.