Repair 7

Shifting through gears is a basic function for vehicles as they gain speed. Some cars, such as Hondas, are outfitted with a hydraulic clutch system that needs proper maintenance to avoid problematic shifting.

Function

A Honda hydraulic clutch is controlled by pressurized fluids for energy transfer between the engine and the transmission, resulting in more speed to the cars wheels. This type of clutch is used in manual transmission Hondas.

Considerations

If problems arise, such as a slipping or clicking within the hydraulic clutch system, verify the transmission fluid is at the proper level in the reservoir located near the rear of the engine. If the fluid is low, check for leaks within the lines since this can lower functionality from lack of hydraulic pressure.

Significance

If there is no leak and the hydraulic clutch is still malfunctioning, it may be necessary to replace the clutch. Over time, the constant squeezing of the clutch disc, when the clutch is engaged, can become worn.

Scooter clutches come in two general design categories: a clutch basket incorporates clutch cork plates; and a rotating wheel that uses shoes similar to a brake drum system to engage and disengage gears. Working on these clutches involves two sets of tools as well: specialty tools that need to be obtained from a manufacturer or dealer; and standard tools that can be purchased at any general hardware store.

Specialty Holding Tools

For clutch basket-type clutches on a scooter the clutch and crankshaft of the engine needs to be kept stationary. A clutch holding tool hooks into the side of the clutch basket and to the engine case. Doing so, when the clutch turns as it is loosened, it stops because of the hook, allowing the clutch holding nut to be loosened or tightened properly.

A different clutch holding type inserts into the clutch body and a mechanic keeps it still by hand while using a different tool in another hand to loosen or tighten the clutch.

Specialty Clutch Loosen/Tightening Tools

Clutch nut tools are specifically designed for certain scooter clutches that use a castellated nut. Similar to the wall top of a castle, a castellated nut has edges that go up and down. The clutch nut tool fits into these grooves to tighten or loosen the securing nut holding the clutch to the crankshaft.

Clutch pullers work the same way as a gear puller. The center of the tool positions on the end of the crankshaft. The clutch puller arms then positions behind the loose clutch and pulls the unit off the crankshaft arm without damaging it or the engine case.

Standard Tools

Socket wrenches and sockets see the most frequent use in tightening or loosening a clutch in a scooter engine. Because of the angle of the securing nut, a regular wrench cannot be used. The socket, instead, sits over the nut and is forced in direction or another by the socket wrench that attaches to the socket.

Screwdrivers sometimes provide a blunt but effective holding tool if they can be positioned correctly to stop the clutch from spinning when its being worked on. The risk, however, is that the hard metal of the screwdriver pressures against the soft metal of the aluminum scooter engine case, denting it.

Compression Tools

For basket clutches, a compression specialty tool is needed. This device acts the same way as the engine by pressing the clutch basket together, allowing the retaining ring that keeps the assembly together to be removed easily. Then the clutch plates and springs that are worn out can be replaced.

The clutch transfers torque to the transmission of a vehicle by engaging the engine to the gearbox. A clutch kit contains two parts of the clutch system.

Clutch Problems

General use over time can lead to clutch problems such as slipping and failing. Other common problems include the clutch making noise, the clutch pedal sticking and a clutch that will not release. A faulty clutch system must be replaced.

Components

A clutch kit contains a clutch disc and a clutch pressure plate. The clutch disc connects directly to the vehicles transmission. The disc creates friction against the pressure plate and flywheel, and allows power to flow from the crankshaft to the transmission. The pressure plate rests against the clutch disc and is bolted to the flywheel. A series of springs allows the plate to flex and create friction when the clutch is engaged and to release when the clutch is disengaged.

Things to Know

In addition to replacing the components in the clutch kit, many mechanics recommend replacing the pilot bearing or pilot bushing and the release bearing. The flywheel should also be resurfaced. Vehicles requiring high torque and old clutch systems should be replaced with a performance clutch system.

Ford equipped the 1991 F-150 trucks with a hydraulic clutch actuation system on the 4.9-, 5.0- or 5.8-liter, naturally aspirated gasoline engines. The hydraulic clutch generates pressure at the master cylinder when the driver presses on the clutch pedal. A nylon hydraulic clutch line carries pressurized fluid to the slave cylinder on the transmission. The line is subject to damage from road debris and proximity to hot engine parts. Replace damaged hydraulic lines to prevent fluid loss and restore clutch function.

Instructions

1

Park the F-150 on level ground and set the parking brake. Place wheel chocks behind the rear wheels. Jack up the front of the truck and support it on jack stands.

2

Locate the hydraulic slave cylinder coupling port on the driver side of the transmission near the bell housing. Place a catch pan under the coupling port. Push the white plastic collar on the fitting toward the transmission, using special tool T88T-70522-A to disengage the quick-connect fitting and then pull the hydraulic line from the transmission.

3

Remove the hydraulic line retaining clip from the bottom of the passenger compartment near the quick-connect fitting. Observe the hydraulic line routing from the master cylinder to the slave cylinder.

4

Locate the clutch master cylinder on the engine firewall next to the brake booster. Remove the 3/32-inch roll pin from the master cylinder near the hydraulic line connector, using a punch. Support the master cylinder while pushing the roll-pin out to prevent stressing and breaking the master cylinder body. Pull the hydraulic line from the master cylinder. Pull the old hydraulic line rubber seal out of the master cylinder using a dental pick. Discard the old roll pin and rubber seal.

5

Install the new rubber seal on the new hydraulic line master cylinder fitting. Route the line down to the transmission. Insert the fitting and rubber seal into the master cylinder. Install the new 3/32-inch roll pin in the master cylinder.

6

Push the quick-connect fitting into the slave cylinder coupling until the coupling snaps in place. Wipe spilled brake fluid from the transmission case with a clean rag. Install the hydraulic line retaining clip.

7

Wipe the clutch master cylinder reservoir cap with a clean rag to remove dirt or other contaminates. Remove the reservoir cap and diaphragm from the reservoir. Install a short length of clear, nylon hose to the bleeder valve on the transmission near the slave cylinder coupling. Lead the loose end of the hose into the catch pan. Open the bleeder valve, using a wrench. Have a helper monitor the fluid level in the reservoir and add DOT 3 heavy-duty brake fluid as necessary to prevent the reservoir from running dry. Observe the fluid stream in the hose and tighten the bleeder valve, using a wrench, once the fluid stream is free of air bubbles.

8

Fill the reservoir up to the Full mark and install the reservoir diaphragm. Push the clutch pedal to the floor. Hold it for a few seconds then completely release the pedal as rapidly as possible. Repeat this action 10 times. Remove the diaphragm and top off the fluid in the reservoir. Repeat this step five times.

9

Install the reservoir diaphragm and cap. Have your helper apply moderate pressure to the clutch pedal and loosen the bleeder valve slightly to release any residual air. Tighten the bleeder valve and remove the clear vinyl hose. Wipe up spilled brake fluid with a rag.

10

Raise the front of the F-150, using the jack. Remove the jack stands, and then lower the truck to the ground.

11

Remove the reservoir cap and diaphragm. Add fluid as necessary to bring the fluid level up to the Full mark. Install the diaphragm and cap.

12

Test the clutch for proper operation in a safe area. Inspect the hydraulic line fittings for leaks. Ensure that the clutch is operating properly before using the vehicle in traffic or other public areas.

Polaris snowmobiles use a continuously variable drive and driven clutch system with a belt. The drive clutch squeezes the drive belt, causing the snowmobile to move. This squeezing cause the drive belts to wear, which allows dirt and debris to float around the engine compartment. This debris can end up inside of your clutch, creating a buildup that results in the clutch not working as efficiently. The result is a loss of horsepower. Rubber and grime can build up on the clutch contact surfaces as well, causing slippage. They need to be cleaned regularly.

Instructions

1

Remove the clutch safety guard by pulling the pins at both ends and pulling the guard straight off. Remove the drive belt by rolling it over the outer face of the secondary clutch until the faces spread and allows the belt to come off. Remove the center, large clutch bolt from the clutch. Screw the clutch puller, which looks like a big bolt, into the center hole of the clutch by threading it in and turning it clockwise. Hold the clutch using the strap wrench to keep it from turning and gradually tighten the clutch puller until the clutch pops off.

2

Use shop solvent to clean any residue inside of the clutch by spraying and wiping. Be careful not to get solvent on the non-metallic parts inside of the clutch. Wipe the inside areas of the clutch dry.

3

Inspect the clutch faces, which are the parts that contact the drive belt. Look for any rubber that has accumulated on these surfaces. Using a soap free souring pad, or steel wool, polish and remove the accumulated rubber. If the rubber does not respond to the pad or steel wool, you can use 180-grit sandpaper. Use care not to over sand, resulting in uneven surfaces. Polish the sanded area when finished with the scouring pad or steel wool to remove scratches.

4

Wash the clutch faces with hot, soapy water. Dish detergent is fine for this. Make sure the water is as hot as possible but not so hot that it burns your hands. Hot water washing will help remove contaminants embedded deep within the aluminum surfaces. Dry thoroughly when finished.

5

Clean the drive belt using hot, soapy water and scrub using a nylon brush with medium to soft bristles. Dry the belt with a towel and allow it to dry completely before you install it.

6

Place the clutch on the engine crankshaft, pushing it on slightly. Install the center clutch bolt and tighten. Install the drive belt and replace all safety guards.

Harley-Davidsons Reduced Effort Clutch Kit, sometimes called "Easy Effort," reduces the effort needed to squeeze the infamous Harley clutch lever by 30 percent, and it is one of two products intended to decrease clutch pull. The reduced effort clutch has been standard equipment on all Twin Cam Harleys since the beginning of the 1996 model year. The reduced effort clutch kit installs on all Twin Cam 88 and Twin Cam B 88 motorcycles sold before 1996.

Instructions

1

Raise the motorcycle on a motorcycle jack until the bike is upright and level, but not elevated.

2

Drain all primary fluid from the primary chain case drain plug on the bottom of the chain case. On recent models, the plug is a hex nut and should be loosened with a socket wrench.

3

Remove the top and rear inspection cover screws on the racetrack-shaped inspection cover in the middle of the primary cover. Remove these screws with an Allen socket. Remove all eleven primary cover screws around the perimeter of the primary chain case cover with an Allen socket.

4

Remove the primary chain case cover, the cover gasket and both tower gaskets. Discard all three gaskets.

5

Disassemble the clutch pack until you can remove the diaphragm spring. Replace the standard diaphragm spring with the diaphragm spring in the reduced effort clutch kit.

6

Replace the primary cover gasket with a new gasket. Replace both tower gaskets with new ones.

7

Reinstall the primary chain case cover. Tighten all eleven primary cover screws with an Allen socket and torque wrench. Tighten the screws to between 108 and 120 inch-pounds.

8

Replace and tighten the top and rear inspection cover screws with an Allen socket and torque wrench. Tighten the inspection cover screws to between 84 and 108 inch-pounds.

9

Drain the transmission through the transmission drain plug using a socket wrench and hex socket.

10

Remove the six clutch release cover screws with an Allen socket and socket wrench. The clutch release cover covers the transmission. Squeeze the clutch lever on the handlebars two or three times to break the clutch release cover free.

11

Remove the clutch release cover and gasket. Discard the gasket.

12

Pull up the clutch cable adjuster boot near the middle of the clutch cable to expose the clutch cable adjustment nut. Loosen the lock nut with an open-end wrench.

13

Completely loosen the clutch cable adjustment nut with an open-end wrench. Unscrew the cable fitting from the clutch release cover.

14

Note the position of the retaining ring opening in the upper left quadrant of the clutch release cover. Remove the retaining ring around the inner ramp with snap ring pliers.

Wash all ball and ramp mechanism components in cleaning solvent.

15

Replace the original inner and outer ramps with the replacement inner and outer ramps included in the kit. Screw, but do not tighten, the clutch cable fitting into the clutch release cover.

16

Place the new outer ramp in the side cover and place the three original ball bearings in the outer ramp slots. Re-seat the retaining ring with snap ring pliers.

17

Connect the end of the clutch cable to the ramp coupling. Install the coupling on the replacement inner ramp. Position the inner ramp and coupling in the clutch release cover.

18

Install a new clutch release cover gasket and replace the clutch release cover. Tighten all six screws to between 84 and 108 inch-pounds with an Allen socket and torque wrench.

19

Tighten the clutch cable fitting with an open-end wrench to approximately 40 inch-pounds of torque.

20

Replace and tighten the transmission drain plug with a socket wrench and hex socket. Replace and tighten the primary chain case drain plug using a socket wrench and hex socket.

21

Refill the transmission with the amount of transmission fluid specified for your motorcycle in your owners manual. Readjust the clutch cable adjusting nut with an open-end wrench until there is no more than 1/8-inch of free play in the clutch handle.

22

Lock the adjusting nut in place by tightening the lock nut with a second open-end wrench. Recover the clutch cable adjusting nut assembly with the rubber boot.

23

Remove the clutch cover in the primary chain case cover by loosening the five Allen bolts with an Allen socket and socket wrench. Remove the clutch cover gasket and discard.

24

Add primary chain case fluid until the fluid just touches the bottom of the clutch plates. Install a new clutch cover gasket, replace the clutch cover and tighten with an Allen socket and socket wrench.

25

Carefully lower and remove the motorcycle jack. Allow the motorcycle to lean left on the jiffy stand.

The clutch cable on a 2010 Harley-Davidson Custom 1200 Sportster runs from the clutch lever on the left side of the handlebars to just under the clutch inspection cover in the middle of the primary. The standard replacement cable is 53 inches long. It should last longer than a year. A common reason to replace a new cable is when you install new handlebars on the bike. Be sure to install the new bars first, then measure for the new cable by duplicating the routing with a piece of wire. You can remove the original cable in a series of straightforward steps.

Instructions

1

Locate the black rubber, accordion-folded clutch adjuster boot in the approximate middle of the clutch cable near the left down tube. Pull up the boot to expose the clutch adjustment nut.

2

Immobilize the clutch cable adjustment nut (the small nut) with a half-inch open end wrench. Loosen the clutch cable adjustment locking nut (the long nut) with a 9/16-inch open end wrench.

3

Turn the cable adjustment nut until there is more than an inch of free play in the clutch lever.

4

Pry loose the pivot pin retaining ring on the bottom of the clutch lever housing with a flathead screwdriver. Pull the retaining pin out of the clutch lever housing.

5

Slide the clutch lever out of the housing. Pull out the clutch cable pin, then pull the upper end of the clutch cable free.

6

Remove the Torx screws and washers from the clutch inspection cover using a Torx socket and a socket wrench. Remove the clutch inspection cover.

7

Pull the spring and hex lock plate off the clutch adjusting screw. Turn the adjusting screw clockwise to release the outer ramp, coupler and inner ramp.

8

Unscrew the nut from the end of the clutch adjusting screw by hand. Pull the hook on the coupler, then pull the clutch cable end fitting from the coupler slot.

9

Turn the end fitting counterclockwise. Pull the lower section of the clutch from the primary cover.

10

Pull the O-ring from the cable end fitting. Loosen the cable clip on the front engine mount and remove the clutch cable from the motorcycle.

In a car with a manual transmission, the function of the clutch is to interrupt the transfer of power between the engine and the drivetrain. This interruption, along with the gradual reapplication of power as the clutch is engaged, allows the car to be started smoothly from a stop and prevents the grinding of gears during shifting. The clutch mechanism consists of several parts that work together to perform this function.

Flywheel

The flywheel is a large metal disc attached the crankshaft of the engine. It is turned by the action of the engine, and it is the point of contact through which power is transferred from the running engine to the transmission and drivetrain. The flywheel has teeth around its circumference, which are engaged by the starter motor in order to turn the engine over; it also has a smooth outer surface that is gripped by the clutch disc when the clutch is engaged.

Clutch Disc and Pressure Plate

The clutch disc is a metal circle covered with a high-friction coating; the disc is pressed against the flywheel when the clutch is engaged. The pressure plate is a mechanism that uses a system of springs and levers to clamp the clutch disc against the flywheel when the clutch is engaged and to release the clutch disc when the clutch pedal is depressed. The hub of the clutch disc is attached to the input shaft of the transmission, and when the flywheel, clutch disc and pressure plate are squeezed together, power is transferred from the engine, causing the transmission shaft to rotate.

Clutch Linkage

The clutch pedal is connected to the clutch mechanism via a linkage system that can be either mechanical or hydraulic. A mechanical linkage consists of rods or cables connecting the clutch pedal to the clutch, while a hydraulic linkage uses lines filled with hydraulic fluid. The function of the linkage is to move the throw-out bearing -- a sliding bearing that moves the pressure plate away from the clutch disc -- when the pedal is depressed.

Automatic Transmissions

Automatic transmissions use a much more complicated mechanism in which sensors and electronics control when the clutch is engaged and disengaged. Hydraulic pressure activates either a number of steel plates and friction discs called a clutch pack -- much like the clutch in a manual transmission -- or a series of transmission bands that tighten and release around the clutch housing. When either of these systems is engaged, power is transferred from the engine to the transmission, and the car moves.