Automatic Transmission Servicing: Other Oldsmobile Bravada III

Transfer Case

Check transfer case fluid level at each engine oil change. Under normal driving conditions, change transfer case fluid every 50,000 miles.

Remove fill plug. Check oil level. If oil level is even with bottom of fill plug opening, level is okay. If level is lower than bottom of fill plug opening, add lubricant as necessary.

Manufacturer recommends DEXRON-III(R) ATF.

Manufacturer recommends Auto Trac II (GM P/N 12378508).

The following refill capacities given are approximate. Correct fluid level should always be determined by marks on dipstick, rather than amount of fluid added. DO NOT overfill. See TRANSMISSION FLUID CAPACITIES table.

TRANSMISSION FLUID CAPACITIES

The following refill capacities given are approximate. Correct fluid level should always be determined by level of fluid at fill hole, rather than amount of fluid added. DO NOT overfill. See TRANSFER CASE FLUID CAPACITIES table.

TRANSFER CASE FLUID CAPACITIES

1. Raise and support vehicle. Place a drain pan under the transmission oil pan. Remove the oil pan drain plug, if equipped.
2. If necessary, remove the bolts and position aside the shift cable bracket for clearance while lowering the pan. It is not necessary to remove the shift cable from the lever or bracket.
3. Remove the oil pan bolts from the front and sides of the pan only. Loosen the rear oil pan bolts approximately 4 turns. Lightly tap the oil pan with a rubber mallet in order to loosen the pan to allow the fluid to drain.
4. Remove the remaining oil pan bolts. Remove the oil pan and the gasket. Grasp firmly while pulling down with a twisting motion in order to remove the filter. (Scheme 148)
5. Remove the filter seal. The filter seal may be stuck in the pump; if necessary, carefully use pliers or another suitable tool to remove the seal. (Scheme 149) Discard the seal. Inspect the fluid color.
6. Inspect the filter. Pry the metal crimping away from the top of the filter and pull apart. The filter may contain the following evidence for root cause diagnosis: Clutch material. Bronze slivers indicating bushing wear. Steel particles.
7. Clean the transmission case and the oil pan gasket surfaces with solvent, and air dry. You must remove all traces of the old gasket material.
8. Coat the new filter seal with automatic transmission fluid. Install the new filter seal into the transmission case. Tap the seal into place using a suitable size socket. (Scheme 150) Install the new filter into the case. Install the oil pan and a new gasket.
9. Install the oil pan bolts. Tighten the oil pan bolts alternately and evenly to specification. See «TORQUE SPECIFICATIONS»(ref-139606-S02627173782002050200000). If previously removed, install the shift cable bracket and bolts. Tighten the bolts to specification.
10. Apply a small amount of sealant to the threads of the oil pan drain plug, if equipped. Install the oil pan drain plug, if equipped. Tighten the oil pan drain plug to specification. See «TORQUE SPECIFICATIONS»(ref-139606-S02627173782002050200000).
11. Lower the vehicle. Fill transmission with appropriate fluid to proper level. See «RECOMMENDED FLUIDS»(ref-139606-S35801020622002050200000) and «FLUID CAPACITIES»(ref-139606-S41135745592002050200000). Check the COLD fluid level reading for initial fill only. Inspect the oil pan gasket for leaks.

Scheme 148

Scheme 149

Scheme 150

Transfer Case (Bravada)

Raise and support the vehicle. Remove the fill plug and drain plug. Ensure an approved drain pan is used when draining the transfer case. Allow the transfer case to drain completely. Apply Pipe Sealant (GM P/N 12346004) or equivalent to the drain plug threads. Install the drain plug. Tighten the drain plug to specification. See TORQUE SPECIFICATIONS . Fill transfer case with appropriate fluid to proper level. See RECOMMENDED FLUIDS and FLUID CAPACITIES . Apply Pipe Sealant (GM P/N 12346004) or equivalent to the fill plug threads. Install the fill plug. Tighten the fill plug to specification. See TORQUE SPECIFICATIONS . Lower the vehicle.

Transfer Case (Envoy & TrailBlazer)

Raise and support vehicle. Remove fill and drain plugs from transfer case. After fluid has drained, reinstall drain plug and tighten to specification. See TORQUE SPECIFICATIONS . Fill transfer case with appropriate fluid to proper level. See RECOMMENDED FLUIDS and FLUID CAPACITIES . Install transfer case fill plug and tighten to specification.

Preparation

1. After transmission repairs, do not reconnect the oil cooler pipes.
2. Remove the fill cap (9) on the Transmission Oil Cooler and Line Flusher (J-35944-A) and fill the flusher tank (4) with 20-21 oz. (0.6L) of flushing solution using the measuring cup (6). DO NOT overfill. Install the fill cap (9) on the flusher and pressurize the flusher tank (4) to 80-100 psi (550-700 kPa), using the shop air supply at the tank air valve (9). (Scheme 151)
3. Connect the flusher discharge hose (5) to the oil cooler return pipe (top connector) (may require J-35944-600). Clip the discharge hose (5) onto the oil drain container. Attach the flusher to the undercarriage of the vehicle with the hook provided, and connect the flushing system feed supply hose (3) from the flusher to the oil cooler feed pipe (bottom connector) (may require J-35944-600). (Scheme 152)
4. With the water supply valve (1) on the flusher in the OFF position, connect the water supply hose (7) from the flusher to the water supply at the faucet. (Scheme 151)and (Scheme 152). Turn ON the water supply at the faucet.

Scheme 151

Scheme 152

TRANSMISSION & OIL COOLER FLOW CHECK

1. Disconnect both hoses from the oil cooler pipes. Connect the oil cooler feed pipe (bottom connector) to the transmission and the return pipe (top connector) (may require J 35944-600) to the discharge hose (5). Clip the discharge hose (5) onto the empty oil drain container. see scheme 8
2. Confirm the transmission is filled with ATF. See «CHECKING FLUID LEVEL & CONDITION»(ref-139606-S32778455702002050200000). Start the engine with the transmission in Park range and run for 30 seconds. A minimum of 2 qts. (1.9L) must be discharged during this 30-second run time. If fluid flow is greater than 2 qts. (1.9L) in 30 seconds, go to next step. If fluid flow is less than 2 qts. (1.9L) in 30 seconds, perform the following diagnosis: Disconnect the oil cooler feed line at the radiator. Connect the discharge hose (5) to the cooler feed line. Clip the discharge hose (5) to the empty oil drain container. see scheme 8 Start the engine with the transmission in Park range and run for 30 seconds. A minimum of 2 qts. (1.9L) must be discharged during this 30-second run time. Perform the following according to the flow rate: Insufficient feed flow: Inspect the transmission. Sufficient feed flow: Inspect the oil cooler return pipe and the oil cooler (and auxiliary cooler, if equipped).
3. Remove the discharge hose (5), reconnect the cooler feed and return pipes to the transmission and refill the unit to the proper fluid level. Inspect the transmission oil cooler pipe connections at the radiator, the auxiliary cooler (if equipped) and the transmission for leaks.

ON-VEHICLE REPAIRS

Various components may be serviced without transmission removal, depending on application. For servicing of these components, see appropriate component under ADJUSTMENTS and/or REMOVAL & INSTALLATION . For additional information on testing electrical components, see appropriate DIAGNOSIS article in AUTOMATIC TRANSMISSIONS.

PARK/NEUTRAL POSITION SWITCH

Note. The following procedure is for vehicles that have not had the switch removed or replaced. If the switch has been removed or replaced, see PARK/NEUTRAL POSITION SWITCH under REMOVAL & INSTALLATION. Apply the parking brake. The engine must start in the Park and Neutral positions only. Check the switch for proper operation. If adjustment is required, proceed as follows: With an assistant in driver's seat, raise and support vehicle. The transmission must be in the Park or Neutral positions only. Loosen the switch retaining bolts and rotate the switch slightly, while the assistant attempts to start engine. After engine starts, turn engine off. Tighten PNP switch bolts to specification. See TORQUE SPECIFICATIONS . Ensure vehicle does not start in any range other than Park and Neutral. Replace the PNP switch if proper operation can not be achieved.

SHIFT CABLE

1. Ensure the range selector cable is not restricted. Ensure the floor shift control is in the Park position. Raise and support the vehicle.
2. Disconnect the range selector cable (4) from the range selector lever ball stud (6). (Scheme 153) Ensure the range selector lever is in the mechanical Park position. (Rotate the range selector lever fully clockwise).
3. Release the locking tab (2) and slide the secondary lock cover (1) to the side. (Scheme 154) Carefully squeeze the locking tabs (1) together to disengage the primary lock. (Scheme 155)
4. Disengage the primary lock. Spring tension will push the end of the cable past the ball stud. Push the end of the cable until it is aligned with the ball stud.
5. Install the cable (4) to the ball stud (6). (Scheme 153) Seat the primary locking tabs (1). (Scheme 155) Slide the secondary lock (2) over the primary lock. (Scheme 154) Lower the vehicle. Check the vehicle for proper operation.

Scheme 153

Scheme 154

Scheme 155

EXTENSION HOUSING REAR OIL SEAL

Note. Tools required: Rear Extension Seal Installer (J-21426), and Transmission Assembly Lubricant (J-36850).

OIL COOLER HOSE/PIPE

Note. The front and rear sections of the cooler lines can be serviced separately. Refer to the appropriate steps when servicing individual lines. Perform the following procedure when removing the cooler lines from the quick connect fittings.

Note. Tools required: Neutral Position Switch Adjustment Tool (J-41364-A).