09/11/2018
RANS S-21 OUTBOUND
TEXT MANUAL
93
The higher rolling drag is completely normal for this bearing and allows for longer
bearing life since the seal will keep most contaminants out. Timken specification
state, for example, that the two 1.25 inch tapered roller bearing used on the
WE51 will produce 18-26 inch pounds of torque (drag) when properly installed.
A light coating of grease on the seal will help reduce the drag on initial
installation. The drag will also reduce after the bearings have been installed and
the seal relaxes in the bore. It is important that the axle nut torque be sufficient to
keep the seal from rotating with the wheel. With the bearings cleaned, dried,
greased, and inserted in the wheel, the axle nut should be tightened until all play
is out of the assembly. Rotate the wheel back and forth while tightening the nut to
help seat the bearings. When all play is out of the assembly, and the wheel
rotates freely, tighten to the next castle slot and insert the cotter pin. The rubber
seal on the tapered roller bearing will remain stationary while the wheel rotates
around it. If the seal is spinning on the axle, the nut should be tightened further
until the seal stops spinning with the wheel.
7.
Apply Thread Sealant to the threads of the brake fitting and install the fitting into
the caliper. The fitting should face upward.
8.
During Final Assembly, route the brake line from the Fuselage bulkhead fitting,
down the Gear Leg, to the Brake Assembly.
NOTE:
The brake line will press into the groove machined into the aft side
of the Gear Leg.