Shawn...The type of gear oil should not make a big difference...There are
MANY tranny's out there working just fine with the standard run of the
mill GL5 oil that is speced for GL3-GL5. Lots of shops just put in GL5
synthetic Penzoil or Quaker state or whatever they generally use with no
issues other than harder shifting when cold. Those of us on the list are
pretty up on the "best stuff" but  we are the exceptions.
If you have any noises that soon after the rebuild...something is wrong
and its not oil related I would think. Amsoil is run by many of you with
no issues.
2nd gear needs to be dealt with. If there is whining on accel, its pinion
shaft related. If it makes noise in neutral with the clutch out, its
mainshaft related. Don't wait fo rit to get worse...
Daryl of AA Transaxle
Duvall, WA. (Seattle area)
(425) 788-4070
1-877-377-0773 (toll free)
aatransaxle.com (web site)