Servicing - A/t Buick Century V

IDENTIFICATION

The manufacturer has developed a system to functionally describe its transmissions and transaxles. The designations indicate number of speeds, type, series and major features. (Scheme 96)

Scheme 96

FWD TRANSAXLE APPLICATION

RWD TRANSMISSION APPLICATION

SERVICE INTERVALS

Check transmission fluid level at every engine oil change. Transmission fluid should be changed and filter replaced every 100,000 miles under normal operating conditions. Under continuous extreme operating conditions (trailer towing, heavy city traffic with ambient temperature more than 90°F (32°C) or delivery service), fluid and filter should be changed every 15,000 miles.

CHECKING FLUID LEVEL

1. Start engine. Operate vehicle for at least 15 minutes or until operating temperature is reached. With engine at curb idle and vehicle on level ground, move gear selector lever through all ranges ending in Park.
2. Remove transmission dipstick, wipe clean and fully reinsert into filler tube. Remove dipstick again, and inspect fluid level. Fluid level should be between ADD 1 PT. OR .5L mark and FULL HOT mark on dipstick.

RECOMMENDED FLUID

Use only Dexron-II, IIE or III Automatic Transmission Fluid (ATF).

FLUID CAPACITIES

FLUID CAPACITIES (1)

Except 4T80-E

1. With vehicle raised and large drain pan placed under transmission oil pan, remove transmission oil pan front and side bolts only. Loosen rear bolts about 4 turns each.
2. Carefully pry pan loose using screwdriver. Allow fluid to drain. Remove remaining bolts, and remove oil pan. Discard old pan gasket. Remove filter and "O" ring or sleeve type seal. Remove any remaining gasket material left on transmission case.
3. Thoroughly clean pan, magnet and screen (if metal) with solvent, and then dry using compressed air. Replace paper filter (if equipped). Install NEW "O" ring on pick-up tube or NEW sleeve into pick-up tube recess. Lubricate with clean oil before installation.
4. Install filter assembly into pick-up tube recess. Install oil pan using NEW gasket, and tighten pan bolts to specification. See «TORQUE SPECIFICATIONS (OIL PAN BOLTS)»(/buick/century/v-1982-1996/remont/automatic-trans/#servicing-at) . Add required amount of fluid to transmission through filler tube.
5. Start engine with gear selector lever in Park and parking brake applied. Engage transmission in each gear, ending in Park. Check fluid level with engine warm. Add fluid if necessary. DO NOT overfill.

4T80-E

1. With vehicle raised and large drain pan placed under transmission oil pan, remove transmission oil pan bolts. Carefully pry oil pan loose using screwdriver. Allow fluid to drain. Remove oil pan. Discard old oil pan gasket. Remove any remaining gasket material left on transmission case.
2. Inspect pan for dents or nicks in sealing surface. Replace if damaged. Clean pan and case sealing surfaces. Surfaces must be clean and dry for proper sealing. Bolts and tapped holes in case must be clean and dry to maintain proper bolt torque.
3. Remaining fluid is held in side cover and torque converter. Removing drain plug inside case, after pan removal, will drain fluid from side cover. It is not necessary to drain torque converter during this procedure.
4. Remove left and right scavenger screens and multi-lip scavenger seals. Inspect scavenger screens for cuts, cracked housings and debris. Replace if damaged.
5. Install scavenger screens and NEW seals. Install oil pan using NEW gasket. Tighten oil pan bolts to specification (3 passes) in sequence. (Scheme 97) See «TORQUE SPECIFICATIONS (OIL PAN BOLTS)»(/buick/century/v-1982-1996/remont/automatic-trans/#servicing-at). Add required amount of fluid to transmission through filler tube.
6. Start engine with gear selector lever in Park and parking brake applied. Engage transmission in each gear, ending in Park. Check fluid level with engine warm. Add fluid if necessary. DO NOT overfill.

Scheme 97

TORQUE SPECIFICATIONS (OIL PAN BOLTS)

THROTTLE VALVE (T.V.) CABLE

Note. T.V. is not used on 4L60-E, 4T60-E and 4T80-E transaxles.

"A" Body (2.2L)

1. Ensure T.V. cable is in full, non adjusted position. (Scheme 98) Ensure T.V. cable operates smoothly and is connected at transaxle.
2. Accelerator cable must be installed before adjusting T.V. cable. Rotate idler pulley (cam) counterclockwise to 62 INCH lbs. (7 N.m) to place cable in adjusted position.

Scheme 98

"N" Body (2.3L)

1. Rotate T.V. cable adjuster body (at transaxle) 90 degrees. (Scheme 99) Pull cable housing until slider mechanism hits stop.
2. Rotate adjuster body back to original position. Using a torque wrench and socket, rotate T.V. cable adjuster hex nut until 75 INCH lbs. (8.5 N.m) is reached. Road test vehicle.

Scheme 99

Except "A" (2.2L) & "N" (2.3L) Bodies

1. Turn ignition off. Press and hold metal readjust tab on cable adjuster at cable support bracket on engine. (Scheme 100) Pull cable housing away from throttle lever until housing stops and is completely against adjuster. Release readjust tab.
2. Manually rotate throttle lever to its full throttle position. Ensure slider moves (ratchets) toward lever when lever is rotated to its full throttle position. Check cable for sticking and binding.

Scheme 100

SHIFT CABLE (FWD)

Except Self-Adjusting

Place gear selector lever in Neutral. Loosen cable adjusting nut at transaxle lever. (Scheme 101) Ensure transaxle lever is in Neutral detent. Tighten cable adjusting nut. DO NOT tighten nut with transaxle lever in Park detent. DO NOT use impact tools on nut.

Note. Most "A", "C", "H", "L", "N" and "W" bodies are equipped with a self-adjusting shift cable.

Self-Adjusting

Place gear selector lever in Neutral. Lift lock button on cable adjuster at transaxle mounting bracket. (Scheme 102) Place transaxle lever in Neutral detent. Push down on lock button.

Scheme 101

Scheme 102

SHIFT CABLE (RWD)

"B" & "D" Bodies

1. Place gear selector lever in Park. Raise and support vehicle. Ensure transmission is fully engaged in Park by rotating drive shaft until parking pawl engages, preventing rotation of shaft.
2. Loosen cable adjusting nut on transmission lever to allow pin to slide freely. With gear selector lever and transmission lever in Park, tighten cable adjusting nut to 15 ft. lbs. (20 N.m). (Scheme 103)

Scheme 103

"F" & "Y" Bodies

Place gear selector lever in Neutral. Raise and support vehicle. Loosen cable adjusting nut at transmission lever. (Scheme 104) Ensure shift shaft lever is in Neutral by rotating lever clockwise to Park detent, and then counterclockwise 2 detents to Neutral. Tighten nut ( DO NOT tighten nut with lever in Park).

Scheme 104

SHIFT LINKAGE ROD (RWD)

Position steering column shift lever in Neutral. Raise and support vehicle. Loosen clamp and clamp screw where end of selector rod extends through hole in clamp. (Scheme 105) Place transmission shift shaft in Neutral. Tighten clamp screw.

Scheme 105

PARK LOCK CABLE (FLOOR SHIFT)

1. With gear selector lever in Park and ignition switch in LOCK position, gear selector lever should not be able to be moved to other gear positions and ignition key should be removable from lock cylinder.
2. With ignition switch in RUN position and gear selector lever in Neutral, ensure ignition switch cannot be turned to LOCK position. If system does not perform as described, unlock park lock cable adjuster (button up). (Scheme 106) Move cable connector nose rearward until key can be removed from ignition. Lock cable adjuster (button down).

Scheme 106

NEUTRAL SAFETY SWITCH

Note. Adjust switch so engine will start in Park or Neutral only.

FWD

1. FWD models use one of 2 different neutral safety switches. (Scheme 107) Ensure shift cable is adjusted. To adjust switch, place gear selector lever in Neutral.
2. Place transaxle lever in Neutral detent. Loosen switch attaching screws. Rotate switch on shifter assembly to align adjustment hole with carrier tang hole.
3. Insert a.094" (2.4 mm) wire gauge about 5/8" into switch holes. Tighten attaching screws. Remove wire gauge. New switches may have a plastic pin installed in hole. Plastic pin is designed to shear off during shift lever operation.

Scheme 107

RWD ("B" & "D" Bodies)

Vehicles with column shift use a mechanical interference-type neutral start system. With gear selector in any position except Park or Neutral, a wedge-shaped finger, attached to ignition switch actuator rod, prevents ignition switch from being rotated to START position.

RWD ("F" & "Y" Bodies)

1. Disconnect negative battery cable. Remove gear selector knob and center console cover. Place gear selector lever in Neutral. If old switch is being adjusted, go to next step. If NEW switch is being installed, go to step 4).
2. Align tang on switch with tang slot on shift control. (Scheme 108) Loosen switch mounting nuts. Rotate switch to align service adjustment hole with carrier tang hole.
3. Insert a.092" (2.34 mm) wire gauge into adjustment hole in top of switch. Rotate switch until pin drops to depth of.59" (15 mm). Tighten mounting nuts to 27 INCH lbs. (3 N.m). Vehicle should only start in Park or Neutral.
4. If NEW switch if being installed, insert switch tang in slot on shift control. Tighten mounting nuts to 27 INCH lbs. (3 N.m).
5. Ensure gear selector lever is in Neutral if holes DO NOT align with shift control. DO NOT rotate switch. Switch is pinned in Neutral. NOTE: If new switch is rotated and pin breaks during installation, use adjustment procedure in step 2).
6. If holes align with shift control, move gear selector lever out of Neutral to shear plastic pin.

TORQUE CONVERTER CLUTCH BRAKE SWITCH

Ensure torque converter clutch brake switch is adjusted to prevent vehicle from stalling at idle due to clutch remaining applied. Ensure brake pedal is fully released. Adjust switch until switch plunger just touches brake pedal lever.

Scheme 108

See also:
• TORQUE SPECIFICATIONS (OIL PAN BOLTS)