Filling
Caution: Operating a manual transmission with the fluid level higher or lower than recommended can result in transmission damage. Do not overfill the transmission; overfilling will force fluid out of the case through the main shaft openings. Fluid overflow may also drain onto the clutch or clutch brake, causing additional problems.
Important: Do not mix types of fluid, because of possible incompatibility. Do not use multi-viscosity fluids or EP (Extreme Pressure) gear fluids. Do not use fluid additives or friction modifiers. If switching from a petroleum-based lubricant to a synthetic, all areas of each affected component must be thoroughly drained. Switching to a synthetic lubricant, when a petroleum-based lubricant has been used for 50,000 miles (80 000 km) or longer may affect transmission performance. Monitor all seal areas for the first 10,000 miles (16 000 km) after changing to a synthetic from a petroleum-based lubricant.
Note: The correct fluid level is established by checking at the fill plug opening.
- Add fluid until it is level with the lower edge of the
fill opening. See Fig.. If the transmission has two fill openings, add fluid to the level
of both fill openings. See Table. for approved transmission lubricants. See Table. for
lubricant capacities.
Table 1, Eaton Fuller Transmission Lubricant Capacities
Transmission Model
Capacity: qt (L)
5-Speed
FS–4205A/B, FS–5205A/B
6.25 (5.9)
FS–6305A/B
9.75 (9.2)
6-Speed
FS–5406A
9.75 (9.2)
FS–6406A, FSO–6406A
9.75 (9.2)
FO–6406A, FO-8406
10.5 (10.0)
FSO–8406A
9.75 (9.2)
Table 1, Eaton Fuller Transmission Lubricant Capacities
- Clean the fill plug, then install it in the transmission.
Tighten the plug as follows:
-
25 to 35 lbf·ft (34 to 48 N·m) for transmissions with 3/4-inch pipe threads.
-
60 to 75 lbf·ft (81 to 102 N·m) for transmissions with 1-1/4 inch pipe threads.
Table 2, Eaton Approved Manual and Automated Transmission Lubricants
Lubricant Type*
Temperature
SAE Viscosity
Synthetic transmission lubricant meeting Eaton PS-386 lubricant specification
All
—
Table 2, Eaton Approved Manual and Automated Transmission Lubricants
* Do not mix types or brands of lubricant.
-
Full
-
Low
Fig. 1, Transmission Oil Level Checking
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