Removal & Installation - A/t GMC Sonoma Syclone

MANUAL

Note. For manual transmission replacement procedures, see appropriate CLUTCHES article.

Removal (BW-1370 & BW-4470)

1. Disconnect negative battery cable. Place transfer case in 4H position. Raise vehicle. Remove skid plate. Drain lubricant from transfer case. Mark front drive shaft and flange for reassembly reference. Remove front drive shaft.
2. Remove left strut rod. Mark rear drive shaft and flange for reassembly reference. Remove rear drive shaft. Disconnect electrical connectors from transfer case. Disconnect shift linkage at transfer case.
3. Support transfer case and remove transfer case-to-transmission adapter bolts. Remove transfer case by moving transfer case rearward until it is free of transmission output shaft. Remove old gasket material.

Installation (BW-1370 & BW-4470)

To install, reverse removal procedure. Install a NEW gasket and fill transfer case with Dexron-II.

Removal (BW-4472)

1. Disconnect negative battery cable. Raise and support vehicle on hoist. Drain transfer case. Mark rear drive shaft components for reassembly reference. Disconnect rear drive shaft from differential and remove from vehicle.
2. Mark front drive shaft components for reassembly reference. Disconnect front drive shaft from transfer case and differential. Remove front drive shaft from vehicle. Disconnect breather hose and electrical connectors from transfer case.
3. Support transfer case and remove transfer case mount and support bracket. Remove transfer case-to-transmission adapter bolts. Move transfer case to rear and lower assembly from vehicle.

Installation (BW-4472)

Position NEW gasket on transfer case adapter with gasket sealer. To complete installation, reverse removal procedure and fill transfer case with Dexron-II.

Removal (NP-205 & NP-241)

1. Disconnect negative battery cable. Raise and support vehicle on hoist. Remove skid plate. Drain transfer case. Mark rear drive shaft components for reassembly reference. Disconnect and remove rear drive shaft from vehicle.
2. Mark front drive shaft components for reassembly reference. Disconnect and remove front drive shaft from vehicle. Disconnect vent hose and electrical connectors from transfer case. Disconnect speedometer cable and shift linkage at transfer case. Remove transfer case strut rod (if equipped).
3. Support transfer case and remove bolts attaching transfer case to transmission adapter. Move transfer case to rear until input shaft clears adapter. Lower transfer case assembly from vehicle.

Installation (NP-205 & NP-241)

To install, reverse removal procedure. Install a NEW gasket and fill transfer case with Dexron-II.

Removal (NP-231)

1. Disconnect negative battery cable. Move transfer case shift lever to 4H position. 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. Disconnect shift linkage from case. Remove catalytic converter hanger bolts at converter and loosen front catalytic converter clamp.
3. Raise transmission and transfer case assembly with jack and remove transmission mount bolts. Remove catalytic converter front bracket. Lower transmission and transfer case. Support transfer case alone and remove transmission-to-transfer case bolts.
4. Remove shift lever bracket from transfer case adapter in order to reach upper left attaching bolt. Separate transfer case from transmission adapter and remove from vehicle.

Installation (NP-231)

To install, reverse removal procedure. Always use a NEW gasket between transfer case and adapter and fill transfer case with Dexron-II.

Removal (Hydra-Matic 4L60/THM 700-R4)

1. Open hood and disconnect negative battery cable. Remove air cleaner. Disconnect TV cable from throttle linkage. Raise vehicle. Drain transmission fluid. Disconnect shift linkage at transmission. Remove drive shaft.
2. Remove transmission support bracket attaching bolts at converter. Position transmission jack under transmission and raise slightly. Remove transmission crossmember-to-mount bolts, crossmember-to-frame bolts and vibration damper (if equipped). Slide crossmember rearward and remove from vehicle. CAUTION: When lowering transmission to gain clearance for additional component removal, use care not to stretch or damage transmission lines, cables or wires.
3. Remove dipstick tube and seal. Cap openings. Disconnect speedometer cable at transmission. Disconnect vacuum modulator line (if equipped). Disconnect all electrical leads at transmission and electrical harness clips on transmission. Disconnect oil cooler lines and cap openings.
4. Disconnect transfer case shifter and move aside. Note location of transmission support brackets before removal for reassembly reference. Remove transmission support braces. Remove torque converter cover and mark flywheel and torque converter to maintain original balance. Remove torque converter-to-flywheel bolts.
5. Support engine and remove transmission-to-engine bolts. Disconnect transmission assembly, being careful not to damage any cables, lines or linkage. Install Torque Converter Holding Strap (J-21366) and remove transmission from vehicle.

Installation (Hydra-Matic 4L60/THM 700-R4)

To install, reverse removal procedure. Mount vibration damper (if equipped) at a 90 degree angle to centerline of transmission.

Removal (Hydra-Matic 3T40/THM 125-C)

1. Place transmission gear selector in Park. Set parking brake and block drive wheels. Although fuel pressure drops to zero when ignition is turned off, loosen fuel filler cap to relieve tank pressure. To further minimize risk of fire and personal injury, cover surrounding areas with a shop rag while removing fuel lines. WARNING: To avoid possible personal injury and fire danger, relieve fuel pressure as outlined in step 1).
2. Disconnect battery cables. Drain cooling system. Remove airflow tube from air cleaner and radiator core support. Disconnect wiring harness at ECM and pull through firewall. Separate engine wiring harness from body connectors and lay harness on engine.
3. Remove accelerator and throttle valve cables. Disconnect fuel lines and transmission shift linkage. Disconnect radiator and heater hoses. Disconnect transmission cooler lines at radiator.
4. Discharge A/C system. Remove A/C compressor and bracket. Disconnect A/C hose at rear of compressor. Cap disconnected hoses and compressor fittings. Remove upper engine strut. Raise and support vehicle.
5. Remove front wheels and stabilizer shaft. Disconnect tie rod ends at steering knuckle. Remove lower control arm ball joints from steering knuckles. See appropriate article in SUSPENSION.
6. Remove drive axles from transaxle and wire out of way. See appropriate article in DRIVE AXLES. Remove intermediate steering shaft pinch bolt. Remove starter.
7. Remove torque converter cover. Remove converter-to-flex plate bolts. Separate exhaust pipe at rear manifold. Support engine/frame/transaxle assembly (with hydraulic table). Remove frame bolts. Lower engine/frame/transaxle assembly. Remove transaxle from assembly.

Installation (Hydra-Matic 3T40/THM 125-C)

To install, reverse removal procedure. Always use a NEW gasket between transfer case and adapter and fill transfer case with Dexron-II.

Removal (Hydra-Matic 4L80-E)

1. Disconnect negative battery cable. Remove air cleaner. Raise vehicle. Drain transmission fluid. Disconnect shift linkage at transmission. Remove drive shaft.
2. Position transmission jack under transmission and raise slightly. Remove transmission crossmember-to-mount bolts, crossmember-to-frame bolts and vibration damper (if equipped). Slide crossmember rearward and remove from vehicle. CAUTION: When lowering transmission to gain clearance for additional component removal, use care not to stretch or damage transmission lines, cables or wires.
3. Remove dipstick tube and seal. Cap openings. Disconnect cooler lines and cap openings. Disconnect transfer case shifter and move aside. Note location of transmission support brackets before removal for reassembly reference. Remove transmission support braces. Remove torque converter cover and mark flywheel and torque converter to maintain original balance. Remove torque converter-to-flywheel bolts.
4. Support engine and remove transmission-to-engine bolts. Disconnect transmission assembly, being careful not to damage any cables, lines or linkage. Install Torque Converter Holding Strap (J-21366) and remove transmission from vehicle.

Installation (Hydra-Matic 4L80-E)

To install, reverse removal procedure. Add Dexron-II Automatic Transmission Fluid.

"S" & "T" SERIES

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

Removal (Hydra-Matic 3L30/THM 180-C)

1. Disconnect negative battery cable. Remove air cleaner and disconnect TV cable at throttle body. Raise and support vehicle. Drain transmission fluid.
2. Mark drive shaft(s) for reassembly reference and remove shaft(s). Disconnect speedometer cable, shift linkage and all electrical leads from transmission. On 4WD models, remove brake line from crossmember clips.
3. Remove transmission support bracket bolts. Disconnect catalytic converter support bracket. Support transmission and transfer case (if equipped). Remove crossmember. Lower transmission enough to provide clearance to reach other components. CAUTION: When lowering transmission to gain clearance for additional component removal, use care not to stretch or damage transmission lines, cables or wires.
4. Remove dipstick tube and seal. Remove oil cooler lines and TV cable. Cap all disconnected lines and openings. Disconnect transfer case shifter and move out of the way. Remove vibration damper and support brackets (if equipped).
5. Remove torque convert cover and mark flywheel-to-torque converter position for reassembly reference. Remove flywheel-to-torque converter bolts. Support engine with jack and remove transmission-to-engine bolts. Slide transmission straight back from engine and install Torque Converter Holding Strap (J-21366) to prevent converter damage during removal. Remove transmission.

Installation (Hydra-Matic 3L30/THM 180-C)

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

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS