HARSH UPSHIFTS/3-2 SHIFTS SERVICE INFORMATION (440-T4)
1985-1986 6000 WITH THM 440-T4 TRANSAXLES (ME9)
I. Harsh Upshifts At High Altitude--1985-1986 6000
Service Action:
Harsh upshifts at high altitudes may be caused by high line pressure due to low engine vacuum and may be corrected on certain transaxle models by installing an aneroid modulator Service Package. Based on vehicle applications, each package contains:
--Vacuum Modulator Asm --Modulator Valve --O-Ring Seal --Instruction Sheet
Service Parts Information:
Service Package Transaxle Model Number Identification (Refer To Figure 1) 8646956 6CFH,6CMH,6CNH,5CP,5CW,5HT
Service Notes:
A new engine to modulator vacuum line must also be installed.
Part Number 14062624
II. Harsh 3-2 Shift at High Altitude--1984-1986
Service Action:
A harsh 3-2 shift at high altitude condition may be corrected by installing a Service Package that contains:
--Package, Spacer Plate Gaskets (2) --Instruction Sheet --Spring, 3-2 Control Valve
Service Parts Information:
3-2 Control Valve Transaxle Model Identification Spring Package Number (Refer To Figure 1) 8646983 6CMH,6CNH,6CFH 8646993 5CP,5CW
Service Manual Reference:
Refer to the THM 440-T4 (ME9) Automatic Transaxle Unit Repair Table Of Contents for control valve assembly service information.
Service Notes:
Before installing a Service Replacement Transaxle Assembly (SRTA) at high altitude, install the new 3-2 control valve spring. Refer to Page 4 of this Bulletin for a geographical listing of high altitude areas.
III. Harsh 3-2 Shift Maneuver (17 To 20 MPH At Any Altitude)
Service Action:
At start of production (SOP) 1987, an orifice pipe has been added between the 1-2 servo release cover plate and the 3-2 coastdown valve to allow a smoother second gear apply. The four new parts installed as a set will service certain past model transaxles and may correct a harsh 3-2 shift maneuver.
Service Parts Information:
Part Transaxle Model Identification Number Description (Refer To Figure 1) ------ ----------- ------------------- 8662322 Body Asm, Oil Pump Complete 6CFH,6CMH,6CNH,BCP,5CW 8662376 Gasket, Release Cover All Models Listed Above B662377 Pipe, Plug & Release Cover All Models Listed Above Assembly 8662394 Clip, Conduit All Models Listed Above
Service Manual Reference:
Refer to the THM 440-T4 (ME9) Automatic Transaxle Unit Repair Table Of Contents for appropriate service information.
Service Notes: ------------- If the new pump body assembly has a 1-pin 3rd clutch switch, remove it and replace with the 2-pin switch from the original pump body assembly. At high altitude, when servicing the transaxle for this condition, also install the 3-2 control valve spring package covered in Section II of this Bulletin. A service package containing these four parts and instructions will be made available soon.
DESIGNATED HIGH ALTITUDE COUNTIES*
STATE OF ARIZONA STATE OF NEVADA Apache Carson City Humboldt Navajo Douglas Lander Elko Lyon STATE OF COLORADO Esmeralda Mineral Adams Jefferson Eureka Storey Alamosa Lake White Pine Arapahoe La Plata Archuleta Larimer STATE OF NEW MEXICO Boulder Las Animas Bernalillo Mora Chaffee Lincoln Catron Rio Arriba Clear Creek Mesa Colfax Sandoval Conejos Mineral Curry San Juan Costilla Moffat De Baca San Miguel Crowley Montezuma Grant Santa Fe Custer Montrose Guadalupe Sierra Dolores Morgan Harding Socorro Delta Ouray Lincoln Taos Denver Park Los Alamos Torrance Douglas Pitkin Luna Union Eagle Pueblo McKinley Valencia Elbert Rio Blanco El Paso Rio Grande STATE OF OREGON Fremont Routt Lake Garfield Saguache Gilpin San Juan STATE OF UTAH Grand San Miguel Beaver Piute Gunnison Surmnit Box Elder Rich Hinsdale Teller Cache Salt Lake Huerfano Washington Carbon Jan Juan Jackson Weld Daggett Sanpete Davis Sevier STATE OF IDAHO Duchesne summit Bannock Custer Emery Tooele Bear Lake Franklin Grand Uintah Bingham Fremont Iron Utah Blaine Jefferson Juab Wasatch Bonneville Madison Kane Wayne Butte Minidoka Millard Weber
Camas Oneida Morgan Caribou Power Cassia Teton STATE OF WYOMING Clark Valley Albany Natrona Carbon Niobrara STATE OF MONTANA Converse Park Beaverhead Madison Fremont Platte Deer Lodge Meagher Goshen Sublette Gallatin Park Hot Springs Sweetwater Jefferson Silver Bow Johnson Teton Laramie Uinta STATE OF NEBRASKA Lincoln Westan Banner Sioux Kimball
*Counties which have substantially all of their area above 4000 ft. Ref. Federal Register, Vol. 42, No. 76, April 20, 1977, pg. 20464.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.
