Pr
eSet Wheel Hubs – Recommended Service
19
ConMet
5. PreSet Wheel Hubs – Recommended Service
CLEAN AND DRY
COMPONENTS
Worn or Damaged Components
Do not repair or recondition wheel-end
components. Replace damaged, worn or out-of-
specification components. Do not mill or machine
any components. Using repaired, reconditioned,
damaged or worn components can cause wheel
end failure, which can result in serious injury and
property damage.
WARNING
!
Hub and Component Cleaning
1. Use a clean filtered solvent to
clean the hub and all wheel end
components.
2. Do NOT clean ground or
polished parts in a hot solution
tank or with water, steam
or alkaline solutions. These
solutions will cause corrosion of
the parts.
3. Clean and inspect the wheel
bearing cups and cones,
race, spindle bearing and seal
journals on the spindle and hub.
Bearings should be cleaned
with clean filtered solvent and
dried with either compressed
air or a lint-free rag.
If compressed air is used, do not spin dry the
bearings. The rollers may score due to lack of
lubricant and rollers could come off which can
result in serious injury. Ensure that the air line is
moisture free.
CAUTION
!
4. Clean and inspect the spindle.
Be sure to clean the full length
of the seal journal on the
spindle.
5. Parts must be dried
immediately after cleaning. Dry
parts with clean paper towels or
rags, or compressed air. Do not
dry bearings by spinning with
compressed air.
6. Apply a light oil to cleaned
and dried parts that are not
damaged and are to be
immediately assembled. Use
only the type of oil used by the
manufacturer. Do NOT apply oil
to the brake linings or the brake
drums.
7. If the parts are to be stored,
apply a good corrosion
preventative to all surfaces.
Do NOT apply the material to
the brake linings or the brake
drums. Store the parts inside
special paper or other material
that prevents corrosion.
INSPECTING BEARING
CUPS AND CONES AND
BEARING SPACER
PreSet and PreSet Plus hubs use a precision-
machined spacer in conjunction with specially
toleranced bearings to control wheel end play.
ConMet recommends installing a new PreSet/
PreSet Plus service kit when inspection indicates
that component replacement is necessary. PreSet/
PreSet Plus service kits are available from a parts
dealer or distributor.
NOTE
If you choose to reuse existing bearings at this
service, they must be inspected in accordance
with the bearing manufacturers recommended
guidelines.
CAUTION
!
If this inspection indicates that existing bearing
component(s) must be replaced, bearing cups and
cones must be replaced as a set. Whenever new
bearings are installed, replacement of the bearing
spacer is also recommended.
CAUTION
!
1. After components have been
properly cleaned, visually
inspect the cups, cones and
spacer for any wear or damage.
Reference TMC RP644 for
proper component inspection
procedures.
-
Bearing spacers should be
visually inspected for signs
of wear or damage. Carefully
inspect the machined ends
of the bearing spacer. Wear
to the bearing spacer can
appear as a sharp ring of
standing metal at either edge
of the machined surfaces
(see figure 45). Replace the
spacer if it has visible wear
evidenced by a raised edge
on the machined end.
8
106864a
NEW
WORN
SHARP
EDGE
Bearing Spacer Wear
FIGURE 45
2. If removal or replacement
is required, follow the steps
outlined below.
REMOVING CUPS IN
ALUMINUM HUBS
1. If the bearing cup must be
removed from an aluminum
hub, remove it by welding a
large bead around the bearing
surface of the steel cup,
letting the assembly cool, and
removing the bearing cup (see
figure 46).
If a welder is not available, heat the hub in an
oven to a temperature not to exceed 300°F and
pound out the bearing cups with a hammer
and mild steel bar, being careful not to damage
the hub.
NOTE