2010-02-22_135159_91_gmc_k1500_trannys.doc - Diesel Place

By Josephine Jenkins,2014-11-08 06:49
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2010-02-22_135159_91_gmc_k1500_trannys.doc - Diesel Place




    Fig. 1: Use guide pins when removing and installing the


    Fig. 2: Exploded view of the transmission mounting 85mm

    5-speed shown, others similar

    1. Place the transmission in third or fourth gear.

    2. Jack up your vehicle and support it with jackstands.

    3. Drain the transmission.

    4. Unplug the speedometer cable or Vehicle Speed Sensor (VSS) connector, back-

    up lamp wire and any other wires that would interfere with transmission removal. 5. Remove the gearshift lever. Plug the opening to keep out dirt. 6. Remove driveshaft after making the position of the shaft to the flange. 7. On 4WD models, remove the transfer case.

    8. If necessary, remove the parking brake and controls.

    9. Remove the exhaust pipes.

    10. If equipped, remove the clutch slave cylinder and position it aside. 11. Position a transmission jack or its equivalent under the transmission to support it. 12. Remove the crossmember. Visually inspect to see if other equipment, brackets or

    lines must be removed to permit removal of transmission.

    NOTE: Mark position of crossmember when removing to prevent incorrect

    installation. The tapered surface should face the rear.

    13. Remove the flywheel housing underpan.

    14. On NVG 4500 models, unbolt the transmission-to-bell housing bolts. 15. On all except the NVG 4500 models, remove the top two transmission-to-housing

    bolts and insert two guide pins.

    NOTE: The use of guide pins will not only support the transmission but will

    prevent damage to the clutch disc. Guide pins can be made by taking two

    bolts, the same as those just removed only longer, and cutting off the

    heads. Cut a slot in the head that will receive a screwdriver. Be sure to

    support the clutch release bearing and support assembly during removal of

    the transmission. This will prevent the release bearing from falling out of

    the flywheel housing.

    16. On all except the NVG 4500 models, remove the remaining bolts and slide

    transmission straight back from engine. Use care to keep the transmission drive

    gear straight in line with clutch disc hub.

    17. Remove the transmission from beneath your vehicle.

    To install:

    Installation is the reverse of removal but please note the following important


    18. Make sure the transmission is in third or fourth gear. On NVG transmissions,

    place the transmission in Neutral.

    19. Coat the input shaft splines with high temperature grease.

    20. On all except the NVG 4500 models, install the guide pins in the top 2 bolt holes. 21. On NVG 4500 models, install the transmission-to-housing bolts.


    Do not force the transmission into the clutch disc hub. Do not let the transmission

    hang unsupported in the splined portion of the clutch disc.

    22. On all except the NVG 4500 models, tighten the transmission-to-engine bolts to

    35 ft. lbs. (47 Nm). On NVG 4500 models tighten transmission-to-housing bolts to

    74 ft. lbs. (100 Nm).

Driven Disc and Pressure Plate



    The clutch driven disc may contain asbestos, which has been determined to be a cancer causing agent. Never clean clutch surfaces with compressed air! Avoid inhaling any dust from any clutch surface! When cleaning clutch surfaces, use a commercially available brake cleaning fluid.

    Fig. 1: Exploded view of typical clutch assembly components

    NOTE: Before removing the bellhousing, the engine must be supported. This can be done by placing a hydraulic jack, with a board on top, under the oil pan.

    1. Remove the slave cylinder.

    2. Remove the transmission.

    3. If equipped, remove the inspection cover from the clutch.

    4. On all NVG 4500 models, remove the bellhousing.

    5. Remove the throwout spring and fork.

    6. Remove the ballstud from the bellhousing.

    7. Install a pilot tool (an old input shaft makes a good pilot tool) to hold the clutch

    while you are removing it.

    NOTE: Before removing the clutch from the flywheel, mark the flywheel,

    clutch cover and one pressure plate lug, so that these parts may be

    assembled in their same relative positions. They were balanced as an


    8. Loosen the clutch attaching bolts one turn at a time to prevent distortion of the

    clutch cover until the tension is released.

9. Remove the clutch pilot tool and the clutch from the vehicle.

    10. Check the pressure plate and flywheel for signs of wear, scoring, overheating,

    etc. If the clutch plate, flywheel, or pressure plate is oil-soaked, inspect the

    engine rear main seal and the transmission input shaft seal, and correct leakage

    as required. Replace any damaged parts.

    Fig. 2: Remove the clutch and pressure plate bolts

    Fig. 3: Remove the clutch and pressure plate assembly . . .

    Fig. 4: . . . then separate the clutch and pressure plate

    Fig. 5: Be sure that the flywheel surface is clean, before

    installing the clutch

14. To install:

    15. On vehicles equipped with a gasoline engine, lubricate the pilot bearing with a

    few drops of machine oil. On vehicles equipped with diesel engines, the bearing

    is sealed and does not require lubrication.

    16. Install a new pilot bearing. A brass drift or equivalent may be used to drive the

    bearing into place on vehicles equipped with a gasoline engine. On vehicles

    equipped with diesel engines, use a suitable pilot bearing driver. 17. Install the pressure plate in the cover assembly, aligning the notch in the

    pressure plate with the notch in the cover flange. Install pressure plate retracting

    springs, lockwashers and drive strap-to-pressure plate bolts. Tighten to 11 ft. lbs.

    (15 Nm). The clutch is now ready to be installed.

    NOTE: The manufacturer recommends that new pressure plate bolts and

    washers be used.

    18. Turn the flywheel until the X mark is at the bottom.

    19. Install the clutch disc, pressure plate and cover, using an old input shaft as an

    aligning tool.

    20. Turn the clutch until the X mark or painted white letter on the clutch cover aligns

    with the X mark on the flywheel.

    21. Install the attaching bolts and tighten them a little at a time in a crossing pattern

    until the spring pressure is taken up. On 198894 models, tighten the bolts to 22

    ft. lbs. (30 Nm) on 4.3L, 5.0L and 5.7L engines; 32 ft. lbs. (43 Nm) on 6.2L and

    6.5L engines; and 24 ft. lbs. (33 Nm) on 7.4L engines. On 199598 gasoline

    models tighten the bolts to 30 ft. lbs. (41 Nm). On 199598 diesel models, tighten

    the bolts to 25 ft. lbs. (34 Nm).

    22. Remove the alignment tool.

    23. Coat the rounded end of the ballstud with high temperature wheel bearing grease. 24. Install the ballstud in the bellhousing. Pack the ballstud from the lubrication fitting.

    Coat the rounded end of the ballstud with grease.

    25. Pack the inside recess and the outside groove of the release bearing with high

    temperature wheel bearing grease and install the release bearing and fork. 26. Install the release bearing seat and spring.

    27. Install the clutch housing. Tighten the bolts to:

    o 198890 R/V Series: 40 ft. lbs. (54 Nm)

    o 198890 C/K Series: 55 ft. lbs. (75 Nm)

    o 1991 Models: 31 ft. lbs. (43 Nm)

    o 199294 Models: 29 ft. lbs. (39 Nm)

    o 199598 Models: 23 ft. lbs. (31 Nm)

    28. Install the transmission.

    29. Install the inspection cover.

    30. Install the slave cylinder. Tighten the bolt to 13 ft. lbs. (18 Nm). 31. Bleed the hydraulic system.

    Fig. 6: Install a clutch alignment arbor, to align the clutch

    assembly during installation

Fig. 7: Apply a thread locking agent to clutch assembly bolts

Fig. 8: Be sure to use a torque wrench to tighten the bolts

    Fig. 9: Grease the clutch release fork ball



    NOTE: It would be best to drain the transmission before starting.

    1. Disconnect the battery ground cable.

    2. Remove the air cleaner.

    3. If equipped, disconnect the detent or TV cable at the throttle lever.

    4. On 4WD models, remove the transfer case shift lever knob and boot.

    5. Raise and support the truck on jackstands.

    6. Disconnect the shift linkage from the transmission.

    7. If it is necessary to disconnect the fuel line, relieve the fuel system pressure.

    Disconnect the fuel lines.

    8. Remove any skid plates that would interfere with transmission removal. 9. Drain the transmission fluid.

    10. Remove the driveshaft(s), after matchmarking its/their flanges. 11. Detach the speedometer cable or Vehicle Speed sensor (VSS) connector,

    downshift cable, vacuum modulator line, shift linkage, throttle linkage, electrical

    wiring, the fluid cooler lines, or any other component that would interfere with

    transmission removal.

    12. Remove the dipstick tube.

    13. If necessary, remove the starter motor.

    14. If necessary, disconnect the support bracket at the catalytic converter. 15. Support the transmission on a transmission jack and unbolt the transmission rear

    mount or the transfer case adapter from the crossmember.

    16. Remove the crossmember.

    17. Remove any transmission support braces. Note their exact positions for


    18. Remove the torque converter underpan, matchmark the flywheel and converter,

    and remove the converter bolts.

    19. If necessary for clearance, move the exhaust system aside.

    20. If necessary for clearance, disconnect the parking brake cable. 21. Remove the transfer case and the adapter.

    22. Support the engine on a jack and lower the transmission slightly for access to the

    upper transmission-to-engine bolts.

    23. Remove the transmission-to-engine bolts and pull the transmission back. Rig up

    a strap or keep the front of the transmission up so the converter doesn't fall out.

    To install:

    Installation is the reverse of removal but please note the following important


    24. Tighten the transmission-to-engine bolts to 35 ft. lbs. (47 Nm).

    NOTE: Make sure that the torque converter-to-flexplate matchmarks are

    aligned, the torque converter is flush with the flywheel and the converter

    turns freely by hand.

    25. On all except 199698 models, tighten the converter bolts to 50 ft. lbs. (68 Nm). 26. On 199698 models, tighten the converter bolts to 46 ft. lbs. (63 Nm). 27. Tighten the transmission support brace bolts to 35 ft. lbs. (47 Nm). 28. On all except 199198 models, tighten the crossmember retainers to 35 ft. lbs.

    (47 Nm).

    29. On 199198 models tighten the crossmember retainers to 56 ft. lbs. (77 Nm). 30. On 198894 4WD models, tighten the transfer case-to-transmission attaching

    bolts to 24 ft. lbs. (32 Nm) and the transfer case-to-frame bracket bolts to 35 ft.

    lbs. (47 Nm).

    31. On 199598 4WD models, tighten the adapter-to-transfer case and adapter-to-

    transmission bolts to 33 ft. lbs. (45 Nm).

    Fig. 1: Automatic transmission and related components

    THM400, 4L60E and 4L80E

    Fig. 2: Automatic transmission and related components



    Shift Linkage

    1. Raise and support the front end on jackstands. Block the rear wheels.

    Fig. 1: Shift linkage THM 400 and THM 700R4


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