Servicing - A/t GMC Typhoon I

IDENTIFICATION

AUTOMATIC TRANSMISSION APPLICATIONS

Bravada, Lumina APV, Silhouette & Trans Sport

Check transmission 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 fluid level at each engine oil change. Under normal griving conditions, on vehicles under 8600 Gross Vehicle Weight Rating (GVWR), change transmission fluid and filter at 30,000 mile intervals. On vehicles over 8600 GVWR, change transmission fluid and filter at 24,000 miles.

If vehicle is used in severe service conditions (commercial use, trailer pulling, constant stop-and-go driving), change fluid and filter every 15,000 miles on vehicles under 8600 GVWR and at 12,000 miles on vehicles over 8600 GVWR.

Transfer Case

Check transfer case fluid every oil change or every 12 months. Check more frequently under severe conditions.

CHECKING FLUID LEVEL

Note. Vehicle must be at normal operating temperature (180-200 degrees) when checking fluid level. One pint of fluid raises level from ADD to FULL mark on dipstick in a hot transmission. DO NOT overfill.

Transmission

With vehicle parked on a level surface and engine at idle, move selector lever through all positions, ending in Park. Let vehicle idle for 3 minutes with accessories off. Remove dipstick, wipe clean and check fluid level. Fluid level should be between ADD and FULL marks on dipstick.

If vehicle has been operated for an extended time at high speed, in city traffic, or pulling a trailer, an accurate fluid level cannot be immediately determined. Transmission must cool for about 30 minutes after vehicle is parked before fluid level can be accurately checked.

Remove fill plug. Check fluid level. If level is not up to fill plug opening, add fluid until fluid reaches bottom of plug opening.

RECOMMENDED FLUID

Transmissions and transfer cases use Dexron-IIE ATF. Although Dexron-IIE is recommended, Dexron-II may still be used. Dexron-II will eventually be replaced with Dexron-IIE.

Transfer Case & Transmission

The transmission refill capacities are approximate. See TRANSMISSION REFILL CAPACITIES and TRANSFER CASE REFILL CAPACITIES . Determine correct fluid level by marks on dipstick. DO NOT overfill.

TRANSMISSION REFILL CAPACITIES

TRANSFER CASE REFILL CAPACITIES

1. Raise and support vehicle. Loosen transmission oil pan bolts. Slowly pry pan loose with a large screwdriver and allow fluid to drain. Remove oil pan and gasket. Remove filter or filter screen. Replace paper element filter (if used) and seal.
2. Clean filter screen (if equipped) and pan with solvent. Blow dry with compressed air. Install oil pan with new gasket. Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(/gmc/typhoon/i-1991-1993/remont/automatic-trans/#servicing-at__torque-specifications) .
3. Add 3 quarts of Dexron-IIE. Start engine and recheck level. Add fluid until level is between FULL and ADD marks on dipstick. Test drive vehicle and recheck fluid level.

Remove drain plug from transfer case. Remove fill plug for easier draining. With fluid fully drained, reinstall drain plug. Fill transfer case to fill plug opening with Dexron-IIE.

Hydra-Matic 3T40, 4L60 & 4T60-E

Depress readjust tab on cable adjuster and hold. (Scheme 351) Move slider back through fitting away from throttle body lever until slider stops at fitting. Release readjust tab and open throttle body lever to full throttle stop. This automatically adjusts slider to correct setting.

Scheme 351

Commercial Van

1. Remove clevis pin retaining clip and clevis pin. (Scheme 352) Move shift lever arm at transmission fully forward and then pull back 2 detents to Neutral position.
2. Loosen jam nut and adjust cable end to align with shift lever arm at transmission. Reinstall clevis pin and clip. Check adjustment, engine should start in Park and Neutral only.

Lumina APV, Silhouette & Trans Sport

1. To adjust shift cable, place shift lever in Neutral. Turn transaxle lever clockwise from Park through Reverse to Neutral.
2. Place shift control assembly in Neutral position. Push tab on cable adjuster to adjust cable in cable mounting bracket.

Except Commercial Van, Lumina APV, Silhouette & Trans Sport

1. 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.
2. Place selector lever in Neutral. Locate proper position using mechanical stops, NOT shift indicator pointer. Hold swivel against shift lever. Install spring washer and screw. Tighten finger tight. Avoid applying force in either direction (along shift rod or lever) while tightening screw to specification. See «TORQUE SPECIFICATIONS»(/gmc/typhoon/i-1991-1993/remont/automatic-trans/#servicing-at__torque-specifications) .

Scheme 352

Trans. Mounted Switch (Lumina APV, Silhouette & Trans Sport)

1. Raise and support vehicle and loosen switch mounting bolts. Align hole in switch lever with hole in switch assembly. Insert a 3/32" gauge pin through switch holes to hold switch in Neutral position.
2. With selector lever on transmission in Neutral detent position, tighten switch mounting bolts and remove gauge pin. Lower vehicle and check operation of switch.

Note. Neutral safety switch adjustment information for all models, except Lumina APV, Silhouette and Trans Sport, is not available from manufacturer.

Hydra-Matic 3T40 & 4T60-E Oil Pan Gasket ID. Scheme 353

Hydra-Matic 4L80-E Oil Pan Gasket ID. Scheme 354

Hydra-Matic 4L60 Oil Pan Gasket ID. Scheme 355

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• TRANSMISSION REFILL CAPACITIES
• TORQUE SPECIFICATIONS