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Overdrive Defeat
If your vehicle has this feature, you can select not to
shift up to fifth gear. This is useful when towing or under
a heavy load.
The overdrive defeat
switch is located in the
instrument panel to
the right of the steering
column.
Press the switch to limit the transmission to fourth gear.
This will allow for fewer downshifts while pulling a
trailer or under a heavy load. The indicator light in the
switch comes on whenever overdrive defeat is active.
Manual Transmission Operation
Using the Clutch
When you are starting to move the vehicle, it is important
to begin with the engine speed at idle. Then start to
engage the clutch and listen for an engine speed drop of
about 100 rpm. At this point, the clutch is engaging, so
you should increase the engine speed and fully engagethe clutch. It is important not to increase the engine speed
sooner or before the clutch begins its engagement. If you
do, you can cause damage to your vehicle.
Double-Clutching
You must use the double-clutching method when you
shift an unsynchronized gear set. Disengage the clutch,
shift to NEUTRAL and engage the clutch. When
upshifting, slow the engine until the engine rpm and
road speed match. When downshifting, accelerate the
engine until the engine rpm and road speed match. Then
quickly disengage the clutch and move the shift lever
to the next gear position and engage the clutch.
Eaton®Fuller®Five and Six-Speed
Transmissions and TTC Spicer
Seven-Speed Transmissions
These transmissions have gears that automatically
synchronize when you shift up or down (except
FIRST (1) gear on the five-speed and seven-speed
transmission which is unsynchronized). Choose the gear
that will maintain the road speed you want while
keeping the engine above two-thirds of the governed
speed. When the engine speed drops below two-thirds
of the governed speed, shift into the next lower gear
before your engine begins to lug. When you shift down,
be sure to double-clutch if required.
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Eaton®Fuller®Nine and Ten-Speed
Non-Synchronized Manual
Transmissions
If your vehicle has one of these transmissions the
engine rpm and road speed must match when upshifting
and downshifting. The label above the windshield will
tell you the operating basics you need to know.
The following are driving tips.
•Always choose an initial starting gear suitable for
the load and terrain.
•Always use double-clutching procedures when
shifting.
•Never move the range shift lever to the LO speed
gear position after HI range preselection, or
anytime the transmission is in the HI range.
•Never move the range knob or lever with the shift
lever in NEUTRAL while the vehicle is moving.
•Never make a range shift while moving in
REVERSE (R).
Clutch Brake (Vehicles with
Non-Synchronized Transmission)
A clutch brake is used to stop transmission input shaft
rotation so that FIRST (1) or REVERSE (R) gear
selection can be initiated when the vehicle is at a
standstill and the engine is idling.
Press the clutch pedal all the way down to the floorboard
to apply the clutch brake.
When using the clutch brake, disengage the clutch
pedal and shift the transmission into either the initial
starting gear or REVERSE (R). If the tooth-butting
occurs between the clutching teeth, re-engage the clutch
while applying light pressure to the shift lever. This
will provide for a smooth shift into either FIRST (1) or
REVERSE (R) gear.
Notice:Using the clutch brake for shifting into any
gear other than FIRST (1) or REVERSE (R) may
cause premature wear of the clutch brake and make
gear shift effort more difficult. Do not use the
clutch brake for shifting after engaging FIRST (1) or
REVERSE (R).
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With cruise control, you can maintain a speed of about
25 mph (40 km/h) or more without keeping your foot
on the accelerator. Cruise control does not work
at speeds below about 25 mph (40 km/h).
If you have an automatic transmission and you apply
your brakes, the cruise control will shut off.
If you have a manual transmission and you apply your
brakes or push the clutch pedal, the cruise control
will shut off.
{CAUTION:
Cruise control can be dangerous where you
cannot drive safely at a steady speed. So, do
not use your cruise control on winding roads
or in heavy traffic.
Cruise control can be dangerous on slippery
roads. On such roads, fast changes in tire
traction can cause excessive wheel slip, and
you could lose control. Do not use cruise
control on slippery roads.
Setting Cruise Control
{CAUTION:
If you leave your cruise control on when you
are not using cruise, you might hit a button
and go into cruise when you do not want to.
You could be startled and even lose control.
Keep the cruise control switch off until you
want to use cruise control.
1. Move the cruise control switch to on.
2. Get up to the speed you want.
3. Press in the set button at the end of the lever
and release it.
4. Take your foot off the accelerator pedal.
The accelerator pedal will not go down.
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Passing Another Vehicle While Using
Cruise Control
Use the accelerator pedal to increase your speed.
When you take your foot off the pedal, your vehicle will
slow down to the cruise control speed you set earlier.
Using Cruise Control on Hills
How well your cruise control will work on hills depends
upon your speed, load and the steepness of the
hills. When going up steep hills, you may want to
step on the accelerator pedal to maintain your speed.
When going downhill, you may have to brake or shift to
a lower gear to keep your speed down. Of course,
applying the brake or clutch takes you out of cruise
control. Many drivers find this to be too much trouble
and don’t use cruise control on steep hills.
If your vehicle is equipped with the exhaust brake option
and the exhaust brake is turned on, the exhaust brake
may come on and try to slow down the vehicle to the set
cruise control speed if the vehicle has accelerated
past the set cruise control speed while going downhill.
Ending Cruise Control
There are four different ways to turn off the cruise
control:
•Step lightly on the brake pedal
(manual and automatic transmissions).
•Press the clutch pedal to the floor
(manual transmissions).
•Move the cruise switch to off, or
•Shift the transmission to NEUTRAL (N).
Erasing Speed Memory
When you turn off the ignition, your cruise control set
speed memory is erased.
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4. With the coolant surge tank pressure cap off, start
the engine and let it run until you can feel the upper
radiator hose getting hot. Watch out for the engine
cooling fan.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge tank
until the level reaches slightly above the FULL
COLD mark.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the clutch is not fully engaged. This improves
fuel economy and reduces fan noise. Under heavy
vehicle loading, trailer towing and/or high outside
temperatures, the fan speed increases when the clutch
engages. So you may hear an increase in fan noise. This
is normal and should not be mistaken as the transmission
slipping or making extra shifts. It is merely the cooling
system functioning properly. The fan will slow down when
additional cooling is not required and the clutch
disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch disengages.
Power Steering Fluid
SeeScheduled Maintenance on page 6-5to determine
when to check your power steering fluid.
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The air supply for this
system must be
maintained by releasing
the drain valve to eject any
moisture that could have
built up in the system.
It is recommended that this system be drained on a
weekly basis.Clutch Pedal Free Travel
If you have a V8 engine and a manual transmission, the
clutch will need adjustment when pedal free travel gets
down to about 1/4 inch (6 mm), as measured at the clutch
pedal pad. You should have 1 1/2 to 2 inches
(38 to 51 mm) of clutch pedal free travel.
If the clutch ever needs service, be sure to use only
approved clutch replacement parts.
Chassis Lubrication
Your Maintenance Schedule provides all of the required
chassis lubrication intervals and identifies proper
lubricants to use. Be sure to see the Maintenance
Schedule before performing any chassis lubrication
service. To determine location of chassis lubrication
items, use the following charts.
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Item Number Item Remarks
1 Brake Camshaft** One fitting each (apply sparingly).
2 Steering Column Slip Joint* One fitting.
3 Steering Drag Link Ends One fitting each end.
4 Pivot Points and Hinges Apply chassis lubricant.
5 Pivot Points and Hinges Apply chassis lubricant.
6 Slack Adjuster** One fitting.
7Brake Cam Roller Pins at interface of pin
and shoe**Apply engine oil.
8 Front Steering KnucklesOne fitting each side, lower bushing.
(Hand-operated grease gun only) Hand-pack upper
bearing.
9 Front Wheel Bearings Hand-pack or lubricate.
10 Steering Tie Rod Ends One fitting each end.
11 Spring Slip Pads* (Multi-Leaf Only) Apply chassis lubricant.
12 Clutch Release Bearing* Cup or fitting.
13 Battery Terminal (except “ST” type) Keep coated with petroleum jelly.
14 Transmission Fill to level of filler plug.
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Item Number Item Remarks
15 Propshaft U-JointsLubricate with GM Part No. 1051344 Wheel Bearing
Lubricant.
16 Parking Brake Clevis Pin$ Apply chassis lubricant.
17 Parking Brake Lever Pivot*, $ Apply chassis lubricant.
18Clutch Release Cross Shaft, Master
Cylinder$Apply chassis lubricant, fill to 1/4 inch (6 mm) below
opening.
19 Release Bearing, Clutch Cross Shaft Two fittings, apply chassis lubricant.
20 Clutch Release Fork Two fittings.
* Applies to some vehicles.
** Applies to air brakes only.
$ Applies to hydraulic brakes only.
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