Removal & Installation - A/t GMC Cab & Chassis R2500

1. Raise and support vehicle on hoist. Drain transfer case. Disconnect speedometer cable. Remove skid plate and crossmember supports as necessary. Disconnect rear drive shaft from transfer case and tie up away from work area.
2. Disconnect front drive shaft from transfer case and tie up shaft away from work area. Disconnect shift lever rod from shift rail link. Support transfer case and remove bolts attaching transfer case to transmission adapter.
3. Move transfer case to rear until input shaft clears adapter and lower assembly from vehicle.

To install, reverse removal procedure.

1. With transfer case shift lever in "4H" position, disconnect negative battery cable. Raise vehicle and remove skid plate. Drain transfer case. Mark front and rear output shaft yokes and drive shafts for reassembly reference and remove shafts.
2. Disconnect speedometer cable and vacuum harness from transfer case. Remove shift lever from case. Remove catalytic converter hanger bolts at converter. Raise transmission and transfer case assembly with jack and remove transmission mount bolts. Remove mount.
3. Lower complete assembly. Support transfer case alone and remove transmission-to-transfer case bolts. Remove shift lever bracket from transfer case adapter in order to reach upper left attaching bolt.
4. Separate transfer case from transmission adapter and remove from vehicle.

To install, reverse removal procedure. Always use a new gasket between the transfer case and adapter.

1. Place transfer case in "4H". Raise vehicle. Drain lubricant from transfer case. Remove cotter pin from shift lever swivel. Mark transfer case front and rear output shaft yokes and drive shafts for assembly alignment reference.
2. Disconnect speedometer cable and indicator switch wires. Disconnect front drive shaft at transfer case yoke. Disconnect parking brake cable guide from pivot located on right frame rail, if necessary. Remove engine strut rod from transfer case.
3. Place support under transfer case and remove transfer case-to-transmission adapter bolts. Move transfer case assembly rearward until free of transmission output shaft and remove assembly. Remove all gasket material from rear of transmission adapter housing.

To install, reverse removal procedure.

1. Disconnect negative battery cable. Remove air cleaner and disconnect T.V. or detent cable at carburetor. Remove dipstick and filler tube support bracket bolt. Raise and support vehicle. Mark drive shaft for reassembly reference and remove from vehicle.
2. Disconnect speedometer cable and shift linkage and all electrical leads from transmission. Remove transmission support brackets (if present) and flywheel inspection cover.
3. Mark flex plate and torque converter for reassembly in same position and remove torque converter-to-flex plate bolts. Disconnect catalytic converter support bracket (if equipped).
4. Remove transmission rear mount bolts. Support transmission with jack and raise slightly. Remove transmission support-to-frame bolts and insulators. Remove support.
5. Lower transmission enough to remove oil cooler lines and T.V. or detent cable from transmission. Disconnect lines and cable. Support engine with jack and remove transmission-to-engine bolts.
6. Disconnect transmission assembly from engine. Install Torque Converter Retainer (J-21366) and remove transmission from vehicle.

To install, reverse removal procedure. Before installing flex plate-to-converter bolts, make certain that the weld nuts on converter are flush with the flex plate and the converter rotates freely by hand in this position. Finger tighten all 3 bolts before tightening to specification.

1. Open hood and disconnect negative cable at battery. Remove engine cover. Disconnect T.V. cable at its upper end. Raise vehicle. Remove drive shaft. Disconnect speedometer cable at transmission. Disconnect shift linkage at transmission.
2. Disconnect all electrical leads at transmission and any clips that retain leads to transmission case. Remove transmission support brace attaching bolts at converter. Disconnect exhaust crossover pipe from exhaust manifolds.
3. Remove converter cover and mark flywheel and torque converter to maintain original balance. Remove torque converter to flywheel bolts and/or nuts. Position a transmission jack under transmission and raise it slightly.
4. Remove transmission crossmember to mount bolts and crossmember to frame bolts (and insulator if used). Slide crossmember rearward and remove from vehicle. Lower transmission to gain access to oil cooler lines and T.V. cable attachments. Disconnect oil cooler lines and T.V. cable. Cap all openings.
5. Support engine with a suitable tool and remove transmission to engine bolts. Disconnect transmission assembly, being careful not to damage any cables, lines or linkage. Install Torque Converter Holder (J-21366) and remove transmission from vehicle.

To install, reverse removal procedure.

1. Disconnect negative battery cable. Remove air cleaner and disconnect T.V. or detent cable at carburetor. Remove transfer case shift lever knob and boot. Raise and support vehicle.
2. Mark drive shafts for reassembly reference and remove from vehicle. Disconnect speedometer cable, shift linkage and all electrical leads from transmission and transfer case. Disconnect transfer case shift linkage.
3. Remove transmission support strut rods and flywheel inspection cover. Mark flex plate and converter for reassembly reference. Remove torque converter-to-flex plate retaining bolts.
4. Disconnect transmission oil cooler lines from transmission. Using a transmission jack, support transmission and transfer case. Remove transfer case-to-frame bracket bolts. Remove mount bolts and transmission crossmember.
5. Remove transmission/transfer case assembly mounting bolts and remove assembly from vehicle. Separate transmission from transfer case.

To install, reverse removal procedure. Before installing flex plate-to-converter bolts, make certain that the weld nuts on converter are flush with the flex plate and the converter rotates freely by hand in this position. Finger tighten all 3 bolts before tightening to specifications.

"S" SERIES

Note. On 4WD models, refer to appropriate TRANSFER CASE removal procedures to remove transfer case.

1. Disconnect negative battery cable. Remove air cleaner and disconnect T.V. cable at carburetor. Raise and support vehicle.
2. Mark drive shaft for reassembly reference and remove shaft. Disconnect speedometer cable, shift linkage and all electrical leads from transmission. On 4WD models, remove brake line to crossmember clips and remove crossmember.
3. Remove transmission support brace bolts and converter cover (if equipped). Remove exhaust crossover pipe and converter attaching bolts. Remove crossover and converter as an assembly.
4. Remove flywheel inspection plate and mark flex plate and torque converter-to-flex plate bolts. Disconnect catalytic converter support bracket.
5. Place a jack under transmission and raise slightly. Remove transmission support-to-frame bolts and insulators. Remove left body mounting bolts and loosen radiator support mount bolt.
6. Raise cab on left side as needed to remove upper transmission-to-engine bolts. Support cab with wood block between body and frame. Slide transmission support towards rear and lower transmission enough to remove oil cooler lines and T.V. cable. Disconnect lines and cable.
7. Support engine with jack and remove remaining transmission-to-engine bolts. Slide transmission away from engine and install Torque Converter Retainer (J-21366) to prevent converter damage during removal. Remove transmission.

To install, reverse removal procedure. Before installing flex plate-to-converter bolts, make certain that the weld nuts on converter are flush with the flex plate and the converter rotates freely by hand in this position. Finger tighten all 3 bolts before tightening to specifications.

TORQUE SPECIFICATIONS - "S" SERIES

TORQUE SPECIFICATIONS - "S" SERIES

TORQUE SPECIFICATIONS - ALL EXCEPT "S" SERIES

TORQUE SPECIFICATIONS - ALL OTHERS

See also:
• TRANSFER CASE