Meritor®
- Park the vehicle on level ground, apply the parking brakes, and chock the front tires.
- Remove the axle carrier fill plug. Then remove the drain plug from the bottom of the housing. Completely drain the lubricant while the unit is warm, to allow the lubricant to drain faster. On tandem-drive axles, it is also necessary to remove the plug at the bottom of the interaxle differential housing to drain that lubricant.
- If equipped with an oil pump, remove the axle oil filter.
Use a suitable filter strap wrench; see Fig.. Discard the old filter.
Fig. 1, Meritor Axle Oil Filter Removal
- Using the recommended drive axle lubricant, coat the face
of the gasket on the new oil filter, if one was removed. Install the
filter over the adapter, and tighten the filter one full turn after
the gasket contacts the base; do not overtighten. See Table. for
recommended lubricants.
Table 1, Meritor Drive Axle Recommended Lubricant
Meritor Drive Axle Recommended Lubricant
Recommended Lubricant Type
Ambient Temperature
Lubricant SAE Viscosity Grade
Meritor Specification
Synthetic Gear Oil
–40°F (–40°C) and Up1
75W–90
0–76–N
–40°F (–40°C) and Up*
75W–140
0–76–M
- There is no upper limit on these outside temperatures.
Table 1, Meritor Drive Axle Recommended Lubricant
- Clean the fill and drain plugs as follows. Change them
if necessary.
- For magnetic plugs, use a piece of key stock or any other convenient steel slug to short the two magnetic poles and divert the magnetic field.
- Check the drain plug for metal particles every 100,000 miles (160 000 km). Clean away the collected material deposited on each pole. Magnets will rapidly lose their effectiveness as collected material bridges the gap between the two poles.
- Each time the oil is changed, replace any magnetic drain plug that does not meet the minimum pickup capacity.
- After cleaning, install the drain plug(s) and tighten to 35 lbf·ft (47 N·m).
Note: Meritor recommends plugs with elements having a minimum pickup capacity of 1.5 pounds (0.7 kg) of low-carbon steel.
- Fill the axle with recommended lubricant as follows. See Table. for drive
axle lubricant capacities.
- With the vehicle on a level surface, fill the axle through the oil fill hole. Allow a few minutes for the oil to flow into the axle. Lubricant should be level with the bottom of the oil fill hole. To check fluid level, see Fig..
- Install and tighten the fill plug 35 lbf·ft (47 N·m).
Note: Some Meritor axles have a small tapped and plugged hole near and below the housing lubricant fill hole. This smaller hole is for a lubricant temperature indicator only, and should not be used as a fill or level hole.
Table 2, Meritor Drive Axle Lubricant Capacities
Meritor Drive Axle Lubricant Capacities
Axle Model
Capacity: pt (L)1
Single-Drive, Single Reduction
- Quantities listed are approximate. Fill axle until lubricant is level with bottom of fill hole with vehicle on level ground.
Table 2, Meritor Drive Axle Lubricant Capacities
RS–21–160
39.5 (18.7)
RS–23–160
39.5 (18.7)
RS–23–161
37.2 (17.6)
RS–23–185
47.3 (22.4)
RS–23-186
47.3 (22.4)
RS–26-185
46.0 (22.0)
Tandem-Drive, Single Reduction
MT–40–143MA–N
Forward
30.2 (14.3)
Rear
25.8 (12.2)c
Table 2, Meritor Drive Axle Lubricant Capacities
RT–40–145, RT–40–145A, RT–40–145P
Forward
30.2 (14.3)
Rear
25.8 (12.2)
Table 2, Meritor Drive Axle Lubricant Capacities
RT–40–160
Forward
39.1 (18.5)
Rear
39.4 (16.3)
Table 2, Meritor Drive Axle Lubricant Capacities
RT–44–145, RT–44–145P
Forward
29.3 (13.9)
Rear
25.1 (11.9)
Table 2, Meritor Drive Axle Lubricant Capacities
RT–46–160, RT–46–160P
Forward
39.1 (18.5)
Rear
34.4 (16.3)
Table 2, Meritor Drive Axle Lubricant Capacities
RT–46–164EH/P
Forward
38.0 (18.0)
Rear
33.0 (15.0)
Table 2, Meritor Drive Axle Lubricant Capacities
RT–50–160
Forward
38.0 (18.0)
Rear
33.0 (15.0)
Table 2, Meritor Drive Axle Lubricant Capacities
RT–52–185
Forward
56.1 (26.5)c
Rear
36.1 (17.1)
Table 2, Meritor Drive Axle Lubricant Capacities
RT–58–185
Forward
56.1 (26.5)
Rear
36.1 (17.1)
Table 2, Meritor Drive Axle Lubricant Capacities
RT–70–380
Forward
54.4 (25.7)
Rear
53.1 (25.1)
Table 2, Meritor Drive Axle Lubricant Capacities
-
Correct (lube level at bottom of fill hole)
-
Incorrect (lube level below fill hole)
Fig. 2, Axle Lubricant Level Inspection
- Whenever the interaxle differential housing has been drained, add an additional 2 pints (0.9 L) of the recommended lubricant directly into the interaxle differential housing.
- Remove the chocks, then drive the vehicle, unloaded, for 1 or 2 miles (2 or 3 km) at speeds not to exceed 25 mph (40 km/h), to thoroughly circulate lubricant throughout the carrier and housing assemblies.
Important: If using synthetic lubricant in an axle equipped with a pump and filter system, the lubricant change interval is extended to 500,000 miles (800 000 km).
Important: Meritor rear axles do not require the use of friction modifiers.
Note: There may be about one pint (0.5 L) of lubricant remaining in the filter. Be careful not to spill it when removing the filter.