sorry to be a noob, but what does this do?

 

I believe most one piece driveshafts require this...

Or if you're like me, and buy a used GT Takeoff 8.8in Rear end with T-lok (for two-wheeled spinning out power!!![8D]), this is also a must.

I followed TacoBills instructions and there haven't been problems for the last 2 weeks I've been driving . Thanks TacoBill!

Although the crush sleeve is not something you really want to mess up or screw around with!

 

Thanks!

 

Is this install similar on a 2011?

 

is this better to install the flange with the rear in the car, ive got the rear sitting on the floor in my office and I cant get flange farther than half way on before the axles start rotating. im thinking I can have the car sitting on the ground so the axles wont turn.

 

It's a lot easier to get the preload correct (important) with the rear end off the car rather than trying to do it under the car if on jackstands.
You need a bar with two holes for the flange bolts so you can brace the bar while attached to the flange so it won't rotate while you tighten the pinion nut. This way you can get the necessary pinion preload that is required. With a lift it would be ok to do it on the car. It's not good to consider just guessing at the preload without measuring. An inch/lb torque wrench should be used for proper preload. Too loose or too tight increases the possibility of destroying your pinion bearings and subsequent rear end problems.