WHEEL ASSEMBLY INSPECTION AND MAINTENANCE

INSPECTION
Failure of any of the following inspections will require maintenance and/or repair as
detailed in the following sections.
1. Insure that the wheel tie bolts are secure and have not worked loose.
2. Visually inspect the wheels for corrosion, cracks, or other visible damage.
3. Inspect the brake disc for evidence of cracks, corrosion, deep grooves, excessive
wear, or other visible damage.

MAINTENANCE AND REPAIR

1. Removal of the wheel assembly
a. Remove wheel hub cap (if so equipped).
b. Remove brake caliper back plates. It is not necessary to disconnect the
hydraulic line.
c. Jack and secure the aircraft in accordance with manufactures instructions.
d. Ensure that the aircraft is stable.
e. Deflate the tire by depressing the valve stem plunger until no more air escapes.

CAUTION: Do not attempt to remove valve stem core, loosen the

axle nut, or disassemble the wheel halves until all tire pressure has
been released. Failure to do so can result in severe personal injury.

f. Remove the valve stem core.

g. Remove the axle cotter pin and axle nut.
h. Carefully slide the wheel assembly off of the axle.

2. Disassembly of the wheel

a. Place the wheel assembly on a suitable working surface. Care must be taken to
prevent damage to the wheel such as scratches and/or nicks which will destroy
the corrosion resistant protection of the wheel.
b. Separate the tire beads from the wheel halves using a tire bead breaker or other
suitable tool. Do not pry between the tire and wheel flange as damage to tire
and/or wheel may occur.
c. Remove the nuts, washers and bolts that hold the wheel halves together.
d. Separate and remove the brake disc from the inner wheel half.
e. Separate each wheel half from the tire using care to not damage the inner tube
or its valve stem.
 f. Remove the retaining snap rings, washers, felt grease seals and wheel bearings
using care to prevent damage to the wheel or bearings.

3. Inspection and Repair

a. Inspect the bearing races for scoring,
corrosion, signs of over heating or other
physical damage. Loose bearing races
are cause for rejection of the wheel half.
If replacement of the race is necessary
carefully press it out using a press and
properly sized bushings as illustrated.
b. Visually inspect each wheel half for cracks, nicks, corrosion or other damage.
Particular attention should be paid to the tire bead seat area. Obvious cracks and
severe corrosion are cause for rejection of the part. A further inspection using
the dye penetrant method should be performed on any part whose serviceability
is questionable. Small nicks, scratches and pits may be blended out and polished
with fine (400 grit) sandpaper and then painted and/or treated for corrosion
resistance.
c. Clean the wheel bearings in a suitable solvent and air dry using compressed air
being careful to not allow the compressed air to spin the bearings.
d. Inspect the bearings for pitting, cracks, evidence of overheating, or excessive
corrosion, any of which is cause for rejection of the part.
e. Inspect the felt grease seals. Excessively worn, hardened or contaminated seals
are cause for replacement. Serviceable seals should be cleaned in solvent, air
dried, and set aside in a clean, protected environment until required for
reassembly.
f. Inspect the felt seal retaining washers and snap rings for distortion, excessive
corrosion or other physical damage which is cause for rejection.
g. Inspect wheel tie bolts for cracks, bending, thread damage, or excessive
corrosion, any of which is cause for rejection. The tie bolts are subjected to
fatigue type loads and should be replaced whenever there is any question as to
their serviceability.
h. Test the wheel tie bolt nuts by installing them onto the bolts. If the nut can be
turned by hand past the self-locking section, it must be replaced.
i. Inspect brake disc for excessive wear, scoring, or corrosion, cracks, warpage, or
other physical damage which is cause for rejection of the part. Replace the disc
if the disc thickness has worn more than 0.025” from new. These dimensions can
be found by visiting www.groveaircraft.com. Minor corrosion and surface
irregularities can be blended using 220 grit sandpaper. Any corrosion on the
non-braking part of the disc should be removed and then painted and/or treated
for corrosion resistance.
4. Reassembly of the Wheel — Refer to Appendix A for Tubeless Wheels
Reassembly of the wheel is basically the reverse of the disassembly process.
Assemble the wheel on a clean, flat surface being careful to not nick, scratch, or
damage the protective finish of the wheel.
a. Reinstall the bearing races if applicable. Heating the wheel and/or cooling the
bearing race is of minimal benefit in the installation process.
(1) Clean the wheel bearing race bore and apply a thin coat of wheel bearing
grease.
(2) Place the bearing race in the wheel bore, being careful to insure that it is
aligned properly and not cocked.
(3) Place the wheel half in the press as
shown in the following figure being
sure to support the wheel half at
the bottom of the bearing seat.
Failure to do this may result in
breakage of the wheel casting if too
much force is applied.
(4) Press the bearing race into the
wheel until it is fully seated.
(5) Remove the wheel from the press and visually check to see that the race is
fully seated and that it is tight in the wheel.
b. Mount the tire on the wheel
(1) Ensure that the wheel is clean and dry. Particular attention should be paid to
the bead area to ensure that it is clean, dry and free of grease or other
contamination which may cause the tire to spin on the wheel as the brakes
are applied.
(2) Insert the inner tube into the tire. Align the red dot on the tire (its lightest
point) with the white or yellow dot on the tube (its heaviest point). If the tube
does not have a white dot, align the red dot on the tire with the valve stem of
the tube. In order to allow the tube to move freely within the tire, it is
recommended that you coat the tube and inner part of the tire with talc
powder.
(3) Inflate the inner tube to approximately 10 psi, allowing it to take the shape of
the tire. Deflate the tire to the point that it just retains its shape.
(4) Place the tire and tube onto the outer wheel half carefully inserting the valve
stem through the hole in the wheel half.
(5) Insert the inner wheel half into the tire with the tie bolt holes aligned and using
care not to pinch the inner tube.
 (6) Place the wheel and tire assembly on a flat working surface with the inner
side of the wheel facing up. Install the brake disc in the inner wheel half and
align the bolt holes with the wheel half. Insert the tie bolts through the brake
disc and wheel.
(7) Rotate the wheel from the working surface in order to be able to attach the
nuts to the tie bolts. Hand tighten a nut with washer on each of the tie bolts.
Care should be taken to ensure that the wheel halves are in contact with each
other and not pinching the inner tube.
(8) Torque the tie bolt nuts to the value shown on the wheel label. Typically this
is 90 inch-pounds for 1/4" bolts and 150 inch-pounds for 5/16" bolts. Observe
the amount of torque required to turn the nut due to the locking friction of the
nut and add this to torque requirements to get the proper torque wrench
reading.
c. Repack the bearings using MIL-G-81322 grease such as Aeroshell 22 or Mobil
28. You may also use the newer Mobil SHC 100, but because it is not compatible
with other wheel grease, the bearings and races must be thoroughly cleaned
before application.
d. With the wheel on a flat working surface, insert a wheel bearing. Lightly coat the
bearing race with bearing grease before installing the bearing.
e. Install the washers, felt grease seal and retention snap ring. A light coat of light
weight oil on the felt grease seal is recommended.
f. Turn the wheel over and repeat steps 3 and 4.
g. Place the wheel in a protective enclosure and inflate to the pressure
recommended by the aircraft manufacturer.

5. Reinstalling the Wheel on the Aircraft

a. Inspect the axle to ensure that it is clean, dry and in serviceable condition.
b. Slide the wheel onto the axle with the brake disc side inboard.
c. Install axle nut and hand tighten ensuring that that inboard wheel bearing is fully
seated on the axle.
d. While slowing rotating the wheel, tighten the axle nut until resistance to turning is
felt. Care must be taken to ensure that the valve stem is not damaged during
this process.
e. Loosen the axle nut only enough so that the wheel runs free, or with very little
drag.
f. Align the axle nut to the nearest cotter pin alignment in the axle. If you need to
move the nut for alignment, first try to tighten it. If the wheel still moves with little
or no resistance, use that alignment. If there is significant resistance to rotation,
loosen the nut to the next hole.
g. Install a new cotter pin. One end of the cotter pin should fold out and bend over
the end of the axle to its center. The other end should be bent back toward the
wheel and shortened if necessary to avoid contact with the wheel. Extreme care
must be taken to ensure that the cotter pin does not interfere with the valve stem
or other parts of the wheel when the wheel is rotated.
h. Reinstall the brake caliper backing plate. Torque the bolts to the value indicated
on the label of the brake caliper and safety wire.
i. Reinstall the wheel hub cap (if so equipped).
j. Rotate the wheel to ensure that it is secure and rotates freely.
k. Lower the aircraft to the ground following aircraft manufacturer’s instructions.

APPENDIX A — SUPPLEMENT FOR TUBELESS TIRES

In addition to the steps of Section 4, the following applies to tubeless wheels:
1. Whenever the wheel halves are separated, a new O-ring must be installed. The
proper O-ring part number can be obtained by contacting Grove Aircraft.
Lubricate the O-ring prior to installation with O-ring lube, wheel grease, or
equivalent
2. Care must be taken to not damage the O-ring when joining the wheel halves.
3. After the tire is placed on the wheel and the wheel halves are joined, use the
following procedure to inflate the tire:
a. Remove the valve from the valve stem.
b. Ensure that the wheel tie-bolts have been torqued to the proper value. As
an extra precaution, you may wish to install the wheel on the aircraft and
tighten the axle bolt as added insurance that the wheel halves will not
separate during tire inflation.
c. Inflate the tire until the bead seat of the tire is firmly seated on the wheel.

CAUTION: Never exceed the wheel rated pressure or the tire rated
pressure. Failure to do so can result in severe personal injury.

d. Install and tighten the valve stem valve.

e. Inflate the tire to the pressure recommended by the aircraft manufacturer.
f. Check to see that the tire is holding pressure. After inflation, check for any
noticeable air leakage. After 24 hours, re-check the tire pressure. If it has
decreased by a noticeable amount, locate and correct the problem which
may be: the tire bead seat not properly seated on the wheel, damaged or
poorly seated O-ring between the wheel halves, or leakage through the
valve stem, valve stem valve or tire itself.