The clutch is a hydraulically operated single plate, dry friction disc, diaphragm spring type.
The clutch is operated by a pedal which is mechanically connected to a clutch master cylinder. When the pedal is depressed, the piston in the master cylinder is moved in the master cylinder bore. This movement compresses the hydraulic fluid in the master cylinder causing pressure which is transferred through a tube to the slave cylinder. The slave cylinder is mounted to the clutch housing with its piston connected to the clutch release lever. The hydraulic pressure in the slave cylinder forces the slave cylinder piston to travel out the cylinder bore and move the clutch release lever, disengaging the clutch.
REMOVAL & INSTALLATION
See Figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12
- Raise the vehicle and support it with floor stands.
- Remove the transmission. On 1970-71 models with the non-removable crossmember, you can move the transmission back and rest it on the crossmember while working on the clutch, if you prefer. You won't have much working area, but it will save you the trouble of getting the transmission out from under the truck.
- Mark the clutch assembly-to-flywheel relationship with paint or a center punch so that the clutch assembly can be reassembled in the same position from which it is removed. Insert a clutch aligning tool (dummy shaft) into the hub. This tool is available from your local Nissan dealer or an auto parts store. It is important to support the weight of the clutch while the retaining bolts are being removed.
- Loosen the clutch cover-to-flywheel attaching bolts, one turn at a time in an alternating sequence, until the spring tension is relieved to avoid distorting or bending the clutch cover. Remove the clutch assembly.
- Inspect the flywheel for scoring, roughness, or signs of overheating. Light scoring may be cleaned up with emery cloth, but any deep grooves or scoring warrant replacement or refacing (if possible) of the flywheel. If the clutch facings or flywheel are oily, inspect the transmission front cover oil seal, the pilot bushing, and engine rear seals, etc. for leakage, and correct before replacing the clutch. If the pilot bushing in the crankshaft is worn, replace it. Install it using a soft hammer. The factory supplied part does not have to be oiled, but check the procedure if you are using an aftermarket part. Inspect the clutch cover for wear or scoring, and replace as necessary. The pressure plate and spring cannot be disassembled; you must replace the clutch cover as an assembly.
- Inspect the clutch release bearing. If it is rough or noisy, it should be replaced. The bearing can be removed from the sleeve with a puller; this requires a press to install the new bearing. After installation, coat the groove in the sleeve, the contact surfaces of the release lever, pivot pin and sleeve, and the release bearing contact surfaces on the transmission front cover with a light coat of grease. Be careful not to use too much grease, which will run at high temperatures and get onto the clutch facings. Reinstall the release bearing on the lever.
- Apply a thin coat of grease to the pressure plate wire ring, diaphragm spring, clutch cover grooves and the drive bosses on the pressure plate.
- Apply a thin coat of Lubriplate® to the splines in the driven plate. Slide the clutch disc onto the splines, and move it back and forth several times. Remove the disc and wipe off the excess lubricant. Be very careful not to get any grease on the clutch facings.
- Assemble the clutch cover and the clutch plate on the clutch alignment arbor.
- Align the marks made on the clutch cover and the flywheel (if the old cover is being used) and install the clutch cover-to-flywheel attaching bolts. Three dowels are used to locate the clutch cover on the flywheel properly. Tighten the bolts in an alternating sequence one turn at a time to 12-15 ft. lbs. (17-22 Nm) on 1970-79 models and 16-22 ft. lbs. (22-29 Nm) on 1980-88 models. Remove the aligning arbor.
- Install the transmission.