96' tahoe- 4wd problems

Having problems with the 4wd switching back to 2wd. It switches into 4wd fine but does not switch back immediatly. Its an automatic switch and the 2wd button is lite up while still engaged in 4wd. It eventully goes back into 2wd after a couple of miles of driving and a loud "thud" is heard. Is this a transfer case problem? any feedback is greatly appreciated. thanx

It may be a problem with the front axle actuator. My 96 did about the same after switching to 2wd, I could still feel the front axle "bind" while turning. Your vehicle probably has the original thermal axle actuator in it and it has to cool down to release the axle. I switched my K1500 over to the '98 style actuator(electric motor) and now have quick engagement and release of the front axle and it stays engaged when the key is off- unless you switch to 2wd

I have this same problem in my 95. Could you tell us more how you made the switch to the electric motor driven design? What parts are needed? How much did this cost? Would this conversion work for a 95 also? Thanks!

Here's a manual replacement:

http://www.off-road.com/chevy/reviews/4x4posi-lok/

Thanks txgearhead,
I sent the company an e-mail asking if their system could help take it out of 4 wheel drive any easier.