35–01 Axle Lubricant Level
Checking
CAUTION
Failure to keep the rear axle filled to the proper
level with the recommended lubricant can result in
rear axle damage.
NOTE: If the vehicle is exposed to water deep
enough to cover the hubs, disassemble and in-
spect them for water damage and/or contamina-
tion. See Group 35 of the
School Bus Chassis
Workshop Manual for instructions.
1.
Clean the oil fill hole plug, located in the carrier
or the side of the axle housing, and the area sur-
rounding it. Remove the plug.
NOTE: Some Meritor axles have a small tapped
and plugged hole located near and below the
housing oil fill hole. This smaller hole is for the
lubricant temperature sensor only, and must not
be used as a fill or level hole.
2.
With the vehicle on level ground, lubricant must
be level with the bottom of the oil fill hole.
If low, add lubricant. See
for Alliance
Brand Product (ABP) axle lubricant capacities.
See
for Meritor axle lubricant capacities
and see
for approved Meritor axle lubri-
cants.
3.
On ABP axles, install the fill hole plug, and
tighten it securely.
4.
On Meritor axles, install the fill hole plug, and
tighten 35 lbf·ft (47 N·m).
ABP Drive Axle Lubricant Capacities
Differential/Hubs
Capacity: quarts (liters)
Differential Only
5.8 (5.5)
Differential and Hubs
7.4 (7.0)
Table 1, ABP Drive Axle Lubricant Capacities
Meritor Drive Axle Lubricant Capacities (single axle)
*
Axle Model
Capacity: pints (liters)
†
RS–13–120
16 (7.6)
RS–15–120
16 (7.6)
RS–17–145
33.6 (15.9)
RS–19–145
34.4 (16.3)
RS–21–145
32 (15.1)
RS–23–160
42 (19.9)
RS–26–180
46.6 (22)
*
Single drive axles equipped with traction equalizers may require a "friction
modifier" to correct a slip-stick condition, as described in the vehicle driver’s
manual. Meritor’s experience shows that the following additives perform ad-
equately: Add Elco No. 2 Friction Modifier (1 ounce [30 ml] of additive for
each 1 pint [0.5 liter] of lube capacity) or Lubrizol No. 797 or 762 (one
ounce [30 mL] of additive for each 1 pint [0.5 liter] of lube capacity).
†
Quantities listed are approximate and include 1 pint (0.5 liter) for each
wheel end and with the drive pinion at 3 degrees.
Table 2, Meritor Drive Axle Lubricant Capacities
Recommended
Lubricant Type
Ambient Temperature
Lubricant SAE
Viscosity Grade
Meritor
Specification
Hypoid Gear Oil
API Service
Classification GL–5
+10°F (–12.2°C) and up
*
85W–140
0–76–A
–15°F (–26.1°C) and up
*
80W–140
0–76–B
–15°F (–26.1°C) and up
*
80W–90
0–76–D
–40°F (–40°C) and up
*
75W–90
0–76–E
–40°F (–40°C) to +35°F (+2°C)
75W
0–76–J
–40°F (–40°C) and up
*
75W–140
0–76–L
Synthetic Gear Oil
–40°F (–40°C) and up
*
75W–90
0–76–N
–40°F (–40°C) and up
*
75W–140
0–76–M
*
There is no upper limit on these ambient temperatures, but axle sump temperature must never exceed 250°F (121°C).
Table 3, Meritor Drive Axle Approved Lubricants
Rear Axle
35
School Bus Chassis Maintenance Manual, July 2003
35/1
