Manual Transmissions and Clutch
Eaton Fuller® Transmission, Operating Tips
Refer to the Eaton website for additional information,www.roadranger.com.
Follow these important operation principles:
For all conditions, use the highest gear that is still low enough to start the vehicle moving with the engine at or near idle speed, and without slipping the clutch excessively.
When operating on-highway with no load or under ideal conditions, use 1st gear to start the vehicle moving forward.
When operating off-road or under adverse conditions, use LOW gear to start the vehicle moving forward.
Use the clutch brake to stop gear rotation when shifting into LOW or reverse while the vehicle is stationary. The clutch brake is actuated by depressing the clutch pedal all the way to the floor.
Partially disengage the clutch to break engine torque during normal gear shifts.
Double-clutch between all upshifts and downshifts that require movement of the shift knob. Splitting of gears does not require movement of the shift knob.
Never push the range-preselection lever down into low range while operating in high range, except when downshifting from 5th gear to 4th gear.
Do not shift from high range to low range at high vehicle speeds.
Never make a range shift or a splitter shift while the vehicle is in reverse.
Never move the range-preselection lever with the transmission in neutral while the vehicle is moving.
Skip ratios while shifting only when operating conditions permit, depending on the load, grade, and road speed.
Never coast with the transmission in neutral.
Eaton Fuller Splitter and Range-Shift Transmissions
Combination splitter and range-shift transmissions allow the choice of two splitter ratios in each gear, as well as the additional ratios provided by a low range and a high range.
General Information, Range-Shift Transmissions
IMPORTANT: Not all ratios are used in each range, and the shift patterns vary between transmissions. Read the shift pattern decal on the dash for the operating instructions for the transmission installed in your vehicle.
The range-preselection lever selects the low or high range for each transmission ratio. It is used once during an upshift sequence and once during a downshift sequence.
To operate a range-shift transmission, move the gear shift lever through all the low-range gear positions and then pull the range-preselection lever up to move into the high-range ratios.
IMPORTANT: Always preselect range shifts when upshifting or downshifting. Preselection requires that the range lever be moved to the necessary position before starting to shift. Preselecting range shifts prevents damage to the transmission and provides for smoother shifts.
General Information, Splitter Control
Depending on the transmission model, some ratios can be split using the splitter-control button (located on the side of the gear shift lever).
IMPORTANT: Always preselect splitter shifts. Preselection requires that the splitter-control button be moved to the necessary position before starting to shift. Preselecting splitter shifts allows for smoother and faster shifting. Complete the shift immediately after preselecting the split to avoid unnecessary wear on transmission components.
Eaton Fuller 13-Speed Splitter and Range-Shift Transmissions
Eaton Fuller 13-speed transmissions have thirteen forward speeds and two reverse speeds. Each transmission consists of a 5-speed front section and a 3-speed auxiliary section. The auxiliary section contains low- and high-range ratios, plus a splitter gear. See Fig. 14.1 for the shift pattern.
- A. High Range
- B. Low Range
- C. High (forward)
- D. Low (rearward)
- 1. Splitter Control Button
Fig. 14.1, Eaton Fuller 13-Speed Transmission Shift Pattern
LOW gear is used only as a starting gear; it is never used with the transmission in high range. The other four ratios are used once in the low range and once again in the high range.
High range gear ratios can be split by using the splitter-control button with the underdrive ratio (RT models), or overdrive ratio (RTO models). Low range gear ratios cannot be split.
Upshifting
1.
Put the transmission in neutral. Start the engine and bring the air system pressure up to 100 to 120 psi (689 to 827 kPa).
2.
Position the range-preselection lever down, in low range.
3.
Make sure the splitter-control button is in the low (rearward) position. See Fig. 14.1 .
4.
To start the vehicle moving, press the clutch pedal to the floor, shift into LOW or 1st gear, then engage the clutch with the engine at or near idle speed. Accelerate to 80 percent of engine governed speed.
5.
Upshift from LOW (or 1st gear) through 4th gear, double-clutching when moving the gear shift lever, and accelerating to 80 percent of engine governed speed.
6.
While in 4th gear, pull the range-preselection lever up into high range and move the splitter-control button to the low (rearward) position. Double-clutch into 5th gear, engage the clutch, and accelerate.
7.
Upshift progressively through the high range gears.
7.
To shift from 5th direct to 5th overdrive (or 5th underdrive to 5th direct on RT model transmissions), move the splitter-control button to the high position, then immediately release the accelerator. Press and release the clutch pedal, then, accelerate again.
7.
Continue upshifting through the shift pattern. Double-clutch when moving the gear shift lever (6th to 7th, etc.); single-clutch during split shifts (6th direct to 6th overdrive, etc.).
Downshifting
IMPORTANT: Never use the clutch brake when downshifting, or as a brake to slow the vehicle.
1.
To downshift from 8th overdrive to 8th direct (or 8th direct to 8th underdrive on RT model transmissions), move the splitter-control button to the low position, then immediately release the accelerator. Press and release the clutch pedal, then depress the accelerator pedal once the transmission has shifted.
2.
Start the downshift from 8th direct to 7th overdrive by moving the splitter-control button to the high position, then double-clutch into 7th gear.
3.
Downshift progressively through each of the high range gears, alternating the procedures in steps 1 and 2 above until reaching 5th direct.
4.
When in 5th direct and ready for the downshift to 4th, push the range-preselection lever down and move the splitter-control button to the high position. Double-clutch into 4th gear, engage the clutch, and depress the accelerator pedal.
5.
Continue downshifting from 4th gear to 1st gear, as conditions require.
Eaton Fuller 18-Speed Splitter and Range-Shift Transmissions
Eaton Fuller 18-speed transmissions have eighteen forward speeds and four reverse speeds. Each transmission consists of a 5-speed front section and a 4-speed auxiliary section. The auxiliary section contains low- and high-range ratios, plus a splitter gear. See Fig. 14.2 .
- A. High Range
- B. Low Range
- C. Overdrive (forward)
- D. Direct Drive (rearward)
- 1. Splitter Control Button
Fig. 14.2, Eaton Fuller 18-Speed Transmission Shift Pattern
LOW gear in the front section is used only as a starting gear; it is never used when the transmission is in high range. LOW gear can be split, to provide both a direct and an overdrive ratio.
Upshifting
1.
Put the transmission in neutral. Start the engine and bring the air system pressure up to 100 to 120 psi (689 to 827 kPa).
2.
Position the range-preselection lever down, in low range and make sure the splitter-control button is in the low position. See Fig. 14.2 .
3.
To start the vehicle moving, press the clutch pedal to the floor, shift into LOW, then engage the clutch with the engine at or near idle speed. To shift from LOW direct to LOW overdrive, move the splitter-control button into the overdrive (forward) position, then immediately release the accelerator. Press and release the clutch pedal, and accelerate.
4.
Upshift from LOW overdrive to 1st direct by first moving the splitter-control button into the direct drive (rearward) position ( Fig. 14.2 ). Double-clutch into 1st gear.
4.
Continue upshifting through the shift pattern. Double-clutch when moving the gear shift lever (1st to 2nd to 3rd to 4th); single-clutch during split shifts (1st direct to 1st overdrive, etc.).
5.
When in 4th overdrive, use the range-preselection lever and the splitter-control button to upshift to 5th gear.
5.
While in 4th gear, pull the range-preselection lever up into high range and move the splitter-control button to the low position. Double-clutch into 5th gear, engage the clutch, and accelerate.
6.
Upshift progressively through the high range gears.
6.
To shift from 5th direct to 5th overdrive (or 5th underdrive to 5th direct on RT model transmissions), move the splitter-control button to the high position, then immediately release the accelerator. Press and release the clutch pedal, and accelerate.
6.
Continue upshifting through the shift pattern. Double-clutch when moving the gear shift lever (6th to 7th, etc.); single-clutch during split shifts (6th direct to 6th overdrive, etc.).
Downshifting
IMPORTANT: Never use the clutch brake when downshifting, or as a brake to slow the vehicle.
1.
To downshift from 8th overdrive to 8th direct (or 8th direct to 8th underdrive on RT model transmissions), move the splitter-control button to the low position, then immediately release the accelerator. Press and release the clutch pedal, then depress the accelerator pedal once the transmission has shifted.
2.
Start the downshift from 8th direct to 7th overdrive by moving the splitter-control button to the high position, then immediately double-clutch into 7th gear.
3.
Downshift progressively through each of the high range gears, alternating the procedures in steps 1 and 2 above until reaching 5th direct.
4.
When in 4th overdrive, push the range-preselection lever down and move the splitter-control button to the high position. Double-clutch through into 4th gear, engage the clutch, and depress the accelerator pedal.
5.
Continue downshifting from 4th overdrive to 4th direct, then 4th direct to 3rd overdrive, etc. Double-clutch when moving the gear shift lever (4th to 3th, etc.); single-clutch during split shifts (4th direct to 3rd overdrive, etc.).
Eaton Fuller 10-Speed Range-Shift Transmissions
Eaton Fuller 10-speed transmissions have ten selective, evenly-spaced forward ratios. Each transmission consists of a 5-speed front section, and a 2-speed auxiliary section. The ten forward speeds are obtained by twice using a 5-speed shift pattern: the first time in low range, the second time in high range. See Fig. 14.3 for the shift patterns, noting that the 4th/9th and the 5th/10th shift positions in the RT (direct ratio) transmissions are directly opposite in the RTO (overdrive ratio) transmissions.
- A. RT Transmissions
- B. RTO Transmissions
- C. High Range
- D. Low Range
Fig. 14.3, Eaton Fuller 10-Speed RT and RTO Transmissions Shift Patterns
Upshifting
1.
Put the transmission in neutral. Start the engine and bring the air system pressure up to 100 to 120 psi (689 to 827 kPa).
2.
Position the range-preselection lever down, in low range.
3.
To start the vehicle moving, press the clutch pedal to the floor; shift into 1st gear, then engage the clutch with the engine at or near idle speed. Accelerate to 80 percent of engine governed speed.
4.
Upshift progressively from 1st gear through 5th gear, double-clutching when moving the gear shift lever.
5.
When in 5th gear and ready to move to 6th gear, pull the range-preselection lever up into the high range. Double-clutch into 6th gear, engage the clutch, and accelerate.
NOTE: If after attempting to shift into the high range the transmission remains in neutral, the range synchronizer protection device may be activated. Move the gear shift lever to neutral to allow the range shift to complete, then shift back into gear.
6.
Upshift progressively through the high range gears, double-clutching when moving the gear shift lever and accelerating to 80 percent of engine governed speed.
Downshifting
IMPORTANT: Never use the clutch brake when downshifting, or as a brake to slow the vehicle.
1.
Downshift progressively through each of the high range gears, double-clutching between shifts.
2.
When in 5th gear and ready to move to 4th gear, push the range-preselection lever down into the low range. Double-clutch into 4th gear, engage the clutch, and depress the accelerator.
3.
Downshift progressively through the low range gears, double-clutching when moving the gear shift lever, as conditions require.
Clutch
Clutch General Information
To ensure long service life of the clutch, start in the right gear, be alert to clutch malfunctions, and know when to adjust the clutch.
Typical operation will not break down the clutch friction surfaces. Heat and wear are almost nonexistent when a clutch is fully engaged. However, during the moment of engagement, when the clutch is picking up the load, considerable heat is generated. If a clutch slips excessively, high temperatures develop quickly between the flywheel, driven discs, and pressure plates. An improperly adjusted or slipping clutch can generate temperatures high enough to destroy the clutch.
Clutch Operation
Clutch Break-In
The clutch may slip for a short time while the friction surfaces break-in on a new or newly-installed clutch.
NOTICE
During initial operation of a new vehicle or a vehicle with a new clutch, check for clutch slippage during acceleration. If the clutch slips, decelerate until the clutch does not slip. Allow the clutch to cool 15 to 30 seconds, then gradually accelerate again. If the clutch continues to slip, repeat the procedure as many as five times. If the clutch slips after five attempts, stop the vehicle and allow the clutch to cool for at least one hour. Notify your Freightliner dealer of the problem.
Moving the Vehicle in the Proper Gear
An empty vehicle can be started in a higher gear than can a partially- or fully-loaded vehicle. Select the gear combination that allows the vehicle to start moving with an idling engine or, if necessary, just enough throttle to prevent stalling the engine.
Gear Shifting Techniques
Upshift into a higher gear only when the vehicle speed allows the transmission input shaft speed to match the flywheel speed when engaging the clutch. This technique results in the smallest speed difference between the clutch disc and the flywheel, and causes the least heat and wear on the clutch assembly. When downshifting, increase the input shaft speed to match the flywheel by slightly revving the engine.
Vehicle Loading
Clutches are designed for specific vehicle applications and loads.
NOTICE
Clutch Brake
Apply the clutch brake by depressing the clutch pedal all the way to the floor plate. The last part of pedal travel will compress the clutch brake plates together, stopping the transmission input shaft. The clutch brake stops the transmission gears from rotating in order to quickly engage a transmission gear after idling in neutral.
NOTICE
Using the Clutch
Use the clutch pedal only when starting the engine, launching the vehicle from a stop, or shifting. To launch a stationary vehicle, depress the clutch pedal all the way to the floor plate (see Clutch Brake above) and shift from neutral to a low gear. Slowly raise your foot until the clutch starts to engage. In this position the clutch is starting to connect the transmission input shaft to the flywheel and is causing the most heat and wear. Slightly increase the engine speed and smoothly allow the clutch pedal to return to the rest position. Do not allow the clutch to remain in the partially-engaged position any longer than necessary to obtain a smooth start.
Double-clutch to shift gears while the vehicle is moving. Depress the clutch pedal most of the way in, but not all the way to the floor plate. Depressing the clutch pedal to the floor plate will engage the clutch brake. Shift the transmission into neutral and fully release the clutch pedal. When upshifting, wait for the engine speed to decrease to the road speed. When downshifting, increase the engine speed to match the road speed. Fully release the clutch pedal after completing the shift.
NOTICE
Holding the Vehicle On an Incline
Always use the vehicle service brakes to prevent the vehicle from rolling backwards while stopped on a hill. Slipping the clutch on a hill to maintain vehicle position will quickly damage the clutch assembly.
Coasting
Coasting with the clutch pedal depressed and the transmission in a low gear can cause high driven disc speed. The clutch speed can be much higher under these conditions than when the engine is driving the clutch. This condition creates a hazardous situation due to the lack of vehicle control and due to the high clutch disc speed. Engaging the clutch under these conditions can cause component damage because of the shock loads to the clutch and drivetrain.
WARNING
Clutch Maintenance
Checking the Clutch Adjustment
Report erratic clutch operation as soon as possible to give maintenance personnel a chance to inspect, lubricate, and adjust the clutch components. Notice any gradual decrease in the distance the clutch pedal moves before resistance is felt.
NOTICE
A correctly adjusted clutch must have about 3/4 inch (19 mm) of travel at the top of its stroke before a stronger resistance can be felt. See Fig. 14.4 . If the free pedal travel is less than this distance, have the clutch inspected.
Check the clutch free pedal travel daily and note it in the driver's report.
- A. Free Pedal
Fig. 14.4, Clutch Free Pedal Travel
Adjusting the Clutch
Clutches have an internal adjustment and external linkage adjustment. See Group 25 of the Century Class Trucks Workshop Manual for clutch adjustment procedures and specifications.
NOTICE
Checking the Clutch Brake Operation
Clutch brake operation can be felt as an increased resistance as the clutch pedal approaches the bottom of its stroke. If the gears grind when shifting into first or reverse gear from neutral with the clutch pedal fully depressed, the clutch pedal is out of adjustment or the clutch brake is worn and needs to be replaced.
Lubricating the Clutch Release Bearing
NOTICE
On vehicles equipped with a greased release bearing, the release bearing should be lubricated at regular intervals. See the Century Class Trucks Maintenance Manual for intervals and procedures.