DANA SPICER Torque-Hub S6B, Assembly And Disassembly, Page: 4 / 24

III
ROLL and LEAK TESTING
Torque-Hub units should always be roll and leak tested before disassembly and after
assembly to make sure that the unit’s gears, bearings and seals are working properly.
The following information briefly outlines what to look for when performing these tests.
The Roll Test:
The purpose of a roll test is to determine if the
unit’s gears are rotating freely and properly. You
should be able to rotate the gears in your unit by applying a constant force to the roll checker. If
you feel more drag in the gears only at certain points, then the gears are not rolling freely and
should be examined for improper installation or defects. Some gear packages roll with more
difficulty than others. Do not be concerned if the gears in your unit seem to roll hard as long as
they roll with consistency.
The Leak Test: (Main Unit)
The purpose of a leak test is to make sure the unit is air tight. You can tell if your unit has a
leak if the pressure gauge reading on your air checker starts to fall once the unit has been
pressurized. Leaks will most likely occur at the main seal or wheneve
r “O” rings or gaskets
are located. The exact location of a leak can usually be detected by brushing a soap and wa-
ter solution around the main seal and where “O” rings or gaskets meet the exterior of the unit,
then checking for air bubbles. If a leak is
detected in a seal, “O” ring, or gasket; the part must
be replaced, and the unit checked. Leak test at 10 psi for 20 minutes.
TIGHTENING and TORQUING BOLTS
If an air impact wrench is used to tighten bolts, extreme care should be taken to insure that
the bolts are not tightened beyond their specified torque. Never use an impact wrench to
tighten shoulder bolts. All shoulder bolts should be tightened by hand.
The following steps describe how to tighten and torque bolts or socket head cap screws in a
bolt circle.
1. Tighten
(but do not torque) bolt “A” until
snug.
2. Go to the opposite side of the bolt circle and
tighten bolt “B” until equally snug.
3. Continue around the bolt circle and tighten
the remaining bolts.
4. Now use a torque wrench to apply the
specified torque to bolt “A”.
5. Continue around the bolt circle and apply an
equal torque to the remaining bolts.