Baker High-Torque Bearing Kit for Wet Primary Applications
The Baker High-Torque Bearing Kit was designed to eliminate lateral walking of the mainshaft race - which is especially found in high horsepower setups. The 34091-85 inner bearing race has been used on Big Twins since 1985. The inner primary bearing rides on this race.
By design, this race press-fits onto the transmission mainshaft. This system works fine for stock engines, however 100 hp+ engines will make this race walk on the mainshaft. Bert Baker of Baker Drivetrain fame says that "if it walks inboard, it will damage the maindrive gear seal and cause a transmission oil leak.
"If it walks outboard, it will cause a primary oil leak. Our high-torque bearing kit for 1991-2007 Big Twin models is designed specifically for closed wet primary applications and eliminates this condition. The kit includes a precision-honed bearing and seal (PN 189-56) - this part is now included in our DD6, OD6, GrudgeBox and DD7 kits."
BAKER DRIVETRAIN