I've seasrched this for a few hours and cant find a solution

this is strange to me. i own a 01 s2k. when the car had been sitting for a few hours, and this is the part that confuses me cause it doesnt happen every time. When the car has sat for an extended period of time and i put it in reverse and begin to take off a single loud knock/click goes off from what sounds like the diff. After that first click/knock it will not make that noise again going forward or reverse. even if i park and get back to driving in a relatively short time it wont make that noise going in reverse. It never makes this noise when going forward. its not only a noise but when it happens i can feel the diff getting resistance from this "thing" and feel it pop passed this point. Ive searched and a lot of people are claiming it's the brakes but that cant be the problem. This definitely sounds/feels like something directly drivetrain related.

any ideas?

 

Probably the brakes that were stuck a little from sitting breaking free of the rotor. That or the axle nut tsb. But I think probably the brakes.
edit: Just read the rest of your post saying you don't think it's that. Definitely sounds like it is from your description but not sure what else it would be.

 

Are your axle nuts the proper torque?

 

let me check

 

I've had both types of pops. If I had the handbrake on overnight, sometimes it will stick when I start to reverse and pop while also jerking a bit as it releases. The axle nut tsb is more of just a noise. A less audible click from the rear that I can't really feel.

 

i get the same thing. i thought it was the brakes sticking aswell

 

It is the axle nut TSB. Remove the nuts, grease the face, torque down to 220-240 ft-lbs and you'll be good to go. Or replace the nuts if you don't like the idea of re-staking them.

It was intermittent for me too. Sometimes it would do it, sometimes it wouldn't. Haven't heard the noise since I torque the nuts.

 

I will have to add this my list of to-do's for the car.