09/11/2018
RANS S-21 OUTBOUND
TEXT MANUAL
92
MAIN GEAR WHEEL/BRAKE INSTALLATION
NOTE:
Trike and Taildragger Wheel/Brake Installations have different
parts for assemblies. Please be sure to refer to the correct parts page
when installing.
1.
Become familiar with the Main Gear Wheel/Brake Installation
PARTS MANUAL
DRAWINGs
and collect the parts shown in the drawings.
2.
Bolt caliper mount and axle to the gear leg assembly as per PARTS MANUAL
DRAWING.
3.
Assemble the wheel and brake kit as per parts manual and manufa
cturer’s
instructions. With the aircraft in a level attitude, the brake assembly will be
orientated to the aft and down.
4.
The tire pressure should be approximately 20 psi for Taildraggers and 25 psi for
Trikes. To install the wheel assembly, the outer brake pad removes via the 1/4"
retainer bolts.
5.
Clean and pack the tapered wheel bearings. The tapered roller bearings are oiled
from the factory for rust prevention, but not greased. The roller bearings should
be cleaned, dried, and then packed with suitable grease. Packing grease without
first removing the oil will dilute the wheel grease, causing it to run out past the
seal and not lubricate properly.
6.
Slip the bearings and wheel / tire assembly back onto the axle. Install the washer
and castle nut. Tighten the castle nut to manufactures specifications or bearing
failure may result. Secure with the large cotter pin.
IMPORTANT INFORMATION:
MATCO Mfg wheels using tapered roller bearings are equipped with Timken
bearings utilizing integrated grease seals on the bearing cone to ensure the
longest possible life. The torque procedure for bearings with these type seals is
different than for tapered roller bearings without them.
A common torque technique for bearings
without integrated seals
is to tighten the
axle nut until the wheel stops spinning freely and then back off to the nearest
locking feature.
THIS TECHNIQUE WILL NOT WORK ON A BEARING WITH
AN INTEGRATED SEAL.
The reason for a different torque technique is that the grease seal produces
some drag and makes the wheel feel somewhat stiff when rotated. Reducing the
axle nut torque until the wheel spins freely will allow the grease seal and the
bearing cone to improperly rotate with the wheel (the cone must not rotate
relative to the axle).