Rocko provided a very good reference.
Take it apart and remove some shims(if there are any left), INSPECT the 5 piece clutch pack......three friction discs and 2 steel spacer plates for wear, warpage, and delamination. If there are no shims to remove, that means it is time for replacing the 5 parts above. We have the parts that you need here.
We will also mail you the instructions.