JLG 660SJ Service Manual - Manual (Page 52)

SECTION 3 - CHASSIS & TURNTABLE
3-2 – JLG Lift – 3121202
3. The tightening of the nuts should be done in stages.
Following the recommended sequence, tighten nuts
per wheel torque chart.
4. Wheel nuts should be torqued after first 50 hours of
operation and after each wheel removal. Check
torque every 3 months or 150 hours of operation.
3.2 DRIVE TORQUE HUB
Roll, Leak and Brake 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.
NOTE: The brake must be released before performing the
roll test. This can be accomplished by either pressur-
izing the brake using the Brake Leak Test procedure
below or by tightening the bolts into the piston
through the end plate (See Brake Disassembly Pro-
cedure)
NOTE: Bolts must be removed while performing brake
release test
THE ROLL TEST
The purpose of the 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 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 leak checking fitting starts to fall
after the unit has been pressurized and allowed to equal-
ize. Leaks will most likely occur at the pipe plugs, the main
seal or wherever o-rings or gaskets are located. The exact
location of a leak can usually be detected by brushing a
soap and water solution around the main seal and where
the o-rings or gaskets meet on 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
rechecked. Leak test at 10 psi for 20 minutes.
THE BRAKE TEST
Table 3-1. Wheel Torque Chart - 9 Lug
TORQUE SEQUENCE
1st Stage 2nd Stage 3rd Stage
40 ft. lbs.
(55 Nm)
95 ft. lbs.
(130 Nm)
170 ft. lbs.
(230 Nm)
Table 3-2. Wheel Torque Chart - 10 Lug
TORQUE SEQUENCE
1st Stage 2nd Stage 3rd Stage
70 ft. lbs.
(95 Nm)
170 ft. lbs.
(225 Nm)
300 ft. lbs.
(405 Nm)
10 LUG PATTERN