Bravada, Lumina APV, Silhouette & Trans Sport
Check transmission/transaxle fluid level at each engine oil change. Under normal driving conditions, change transmission fluid and filter every 100,000 miles. Under severe driving conditions, change fluid and filter every 15,000 miles.
Except Bravada, Lumina APV, Silhouette & Trans Sport
Check transmission/transaxle fluid level at each engine oil change. Under normal driving conditions, for vehicles over 8600 GVWR, change transmission fluid and filter every 24,000 miles. For vehicles under 8600 GVWR, change fluid and filter every 30,000 miles.
Under severe driving conditions, for vehicles over 8600 GVWR, change transmission fluid and filter every 12,000 miles. For vehicles under 8600 GVWR, change fluid and filter every 15,000 miles.
Transfer Case
Check transfer case lubricant at every oil change or every 12 months. Under severe conditions check more frequently.
Transmission/Transaxle
With vehicle parked on a level surface and engine at idle, move selector lever through all positions, ending in Park. Remove dipstick, wipe clean and check fluid level. Fluid level should be between ADD 1 PT. and FULL marks on dipstick. If vehicle has been driven for extended period of time at high speed, in city traffic or pulling a trailer, an accurate fluid level cannot be immediately determined. Allow transmission/transaxle to cool for about 30 minutes after vehicle is parked, then check fluid level.
Remove fill plug. Check oil level. If level is not up to fill plug opening, add lubricant as necessary.
The transmission/transaxle refill capacities given below are approximate. Correct fluid level should always be determined by marks on dipstick, rather than by amount of fluid added. DO NOT overfill transmission/transaxle.
| Application | Refill (Service) Qts. (L) | Dry Fill (Overhaul) Qts. (L) |
|---|---|---|
| 3L30 | 3.7 (3.5) | 5.1 (4.9) |
| 3T40 | 4.0 (3.8) | 7.0 (6.6) |
| 4L60 & 4L60-E | 5.0 (4.8) | 11 (10.6) |
| 4T60-E | 6.0 (5.7) | 7.1 (6.7) |
| 4L80-E | 5.0 (4.7) | 11.5 (10.9) |
TRANSMISSION/TRANSAXLE REFILL CAPACITIES
| Application | Capacity |
|---|---|
| Models 231 & 233 | 2.2 Pts. (1.1L) |
| Model 241 | 5.2 Pts. (2.5L) |
| Models 4401 & 4472 | 2.9 Pts. (1.4L) |
| Model 4470 | 6.6 Pts. (3.1L) |
TRANSFER CASE REFILL CAPACITIES
- Loosen transmission/transaxle oil pan bolts. Pry pan loose with a large screwdriver and allow fluid to drain. Remove oil pan, gasket and filter or filter screen. Replace paper element filter (if equipped).
- Clean filter screen and pan with a solvent and blow dry with compressed air. Install oil pan with NEW gasket. Add fluid to proper mark on dipstick.
Note. On 4WD vehicles it may be necessary to remove the crossmember at the rear of the transmission to allow adequate clearance for transmission oil pan removal. Forcing the pan past the crossmember may damage the internal transmission wiring harness or solenoid connections.
Remove drain plug from transfer case. Remove fill plug for easier draining. With fluid drained, reinstall drain plug. Fill transfer case to fill plug opening with appropriate fluid.
THROTTLE VALVE (T.V.) CABLE
Note. The Hydra-Matic 4L60-E, 4T60-E and 4L80-E are electronically controlled transmissions/transaxles and do not require adjustment.
3T40 & 4L60
Depress metal lock tab on adjuster and hold. Move slider back through fitting away from throttle body lever until slider stops at fitting. (Scheme 100) Release lock tab and open throttle body lever to full throttle stop. This automatically adjusts slider to correct setting.
Scheme 100
Commercial Van
- Remove clevis pin retaining clip and clevis pin. Move shift lever arm at transmission fully forward and then pull back 2 detents to Neutral position.
- Loosen jam nut and adjust cable end to align with shift lever arm at transmission. Tighten jam nut. Reinstall clevis pin and clip. Ensure engine starts in Park and Neutral only.
Lumina APV, Silhouette & Trans Sport
Place shift lever in Neutral. Neutral can be found by rotating transaxle select lever clockwise from Park to Reverse to Neutral. Place shift control lever in Neutral. Push tab on cable adjuster to adjust cable in cable mounting bracket.
All Models Except Commercial Van, Lumina APV, Silhouette & Trans Sport
- Ensure shift tube and lever are free in steering column. To adjust linkage, remove screw and spring washer from swivel. Turn transmission lever clockwise to stop, then counterclockwise 2 detents. This is Neutral position.
- Place selector lever in Neutral. Locate proper position using mechanical stops, NOT indicator pointer. Hold swivel against shift lever. Install spring washer and screw and tighten finger tight. Avoid applying force in either direction (along shift rod or lever) while tightening screw to 20 ft. lbs. (27 N.m).
PARK/LOCK CONTROL CABLE
Note. Park/Lock Control Cable adjustment information for Astro, "C" & "K", "P", Safari and "S" & "T" Series is not available from manufacturer.
Lumina APV, Silhouette & Trans Sport)
- Lift cable lock button. Move shift lever to Park. Snap cable connector into shifter base. Ensure ignition key is in RUN position.
- Snap cable housing into inhibitor. Turn key to LOCK position. Snap cable end onto park lock lever pin. Remove slack from cable connector. Snap cable connector lock button down.
NEUTRAL SAFETY SWITCH
Note. Neutral safety switch adjustment information for Astro, "C" & "K", "P", Safari and "S" & "T" Series is not available from manufacturer.
Column Mounted Switch (Bravada, "G" Series, Jimmy, Safari and Sonoma)
With shift selector in Neutral, neutral safety switch is adjusted after it is installed and shift selector is moved from Neutral to Park.
Trans. Mounted Switch (Lumina APV, Silhouette & Trans Sport)
- Raise and support vehicle and loosen switch mounting bolts. Align hole in switch lever with hole in switch assembly. Insert a 3/32" (2.5 mm) gauge pin through switch holes to hold switch in Neutral position.
- With selector lever on transmission in Neutral detent position, tighten switch mounting bolts and remove gauge pin. Lower vehicle and check operation of switch.