904 Steel Planetary Upgrade

Got 6 904s in use...actually one is a spare...all have the 5.0 lever. Some have aluminum planetary gears some dont...dont seem to have a problem with either.

A very good upgrade for the 904 is replacing the large wound spring in the front clutch pac with a 24 spring kit......or....ATI make a large wound spring but it is wound the opposite direction then the stock one...The stock one will let the front clutches drag at high rpm.....what rpm I dont know...but i use the 24 spring kit and never had a problem with the front clutch pac...I got one trans with the ATI spring...