I am having serious binding issues with the two gears in my center diff. Here is how it started. I noticed the center drive shaft drive cup going to the front diff was loose and lost a set screw. So I ordered after market cups with the stainless sleeves pressed on etc. I installed the new cups and reinstalled the assembly back in the truck. Now it is binding bad when I bolt the two center diff mounts down to secure it. I have yet to buy the aluminum mounts and still use the plastic ones BTW. So I then started thinking it had something to do with the new cups. I have another new center diff assembly with all stock parts and it still binds after tightening it down completely. I have had this diff in and out probably ten times now with different combinations. I am so frustrated with this thing it is sickening!! I have tried moving the shims behind the bearings in the mounts, I put two shims in one side then tried the other,I tried just one shim on one mount, I tried a shim in each mount and ALL have done the same thing. I have the teeth on the crown gear facing the rear of the vehicle and I have the mounts installed with the wider side facing down. Pretty sure I have the install correct . Hopefully somebody else has had a similar issue that can enlighten me on the subject before I make it an RC molotov coctail...