SERVICE INFORMATION ON 4T60-E TRANSAXLE W/3.4 TWIN DOHC

Subject: SERVICE REPLACEMENT TRANSMISSION ASSEMBLY 4T60-E (SRTA)

Model and Year: 1991 LUMINA WITH 4T60-E AUTOMATIC TRANSMISSION AND 3.4L ENGINE

BULLETIN COVERS:

Service information on a new HYDRA-MATIC 4T60-E transaxle model for the 3.4L twin DOHC engine (VIN X) used in 1991 W-cars. The HYDRA-MATIC 4T60-E Service Replacement Transmission Assembly (SRTA) Program will service the 1CWW model. The SRTA model, complete overhaul and on-car service parts can be ordered for the HYDRA-MATIC 4T60-E model from your local General Motors Service Parts Operation (GMSPO) Parts Distribution Center.

The HYDRA-MATIC 4T60-E is a new transaxle model with electronic shift controls to control shift points.

SRTA ADVANTAGES:

- A SRTA is the product of a highly successful, customer satisfaction driven program that parallels the existing HYDRA-MATIC 3T40, HYDRA-MATIC 4T60 and HYDRA-MATIC 4L60 programs.

- All SRTA units are designed and remanufactured to current engineering specifications and are often less costly than major overhaul.

- GMSPO Parts Distribution Centers are committed to 48 hour maximum delivery time for all SRTA models, with no VIP charges.

IN THE INTEREST OF CUSTOMER SATISFACTION, SRTA MODELS SHOULD ONLY BE CONSIDERED WHEN THE PROJECTED COST OF REPAIR EXCEEDS THE COST OF A SRTA REPLACEMENT.

RETURN ALL TRANSMISSION/TRANSAXLE SRTA CORES FOR ALL PROGRAMS IN A TIMELY MANNER TO THE LOCAL GMSPO PARTS DISTRIBUTION CENTER (PDC). THIS WILL HELP ENSURE THAT THE SRTA PROGRAM REMAINS A HIGHLY SUCCESSFUL, CUSTOMER SATISFACTION DRIVEN PROGRAM.

GENERAL GUIDELINES:

o Overhaul, On-Car Service or SRTA

- Dealership overhauls for the entire transaxle will be allowed after the technician has taken the HYDRA-MATIC 4T60-E two-day training class number 17002.03. Until then, on-car repairs (see Figure 1) and SRTA will be the only service options.

Parts needed to perform a complete overhaul or on-vehicle service of a HYDRA-MATIC 4T60-E transaxle are available through your local Parts Distribution Center (PDC).

COOLER FLUSHING:

IMPORTANT: Cooler flushing MUST be performed whenever a transmission/transaxle is removed for service. It is essential to flush the cooler for SRTA installation, major overhaul, in any case of pump or torque converter replacement, or when fluid contamination is suspected. Use Kent-Moore tool J 35944 to flush the cooler.

1991 HYDRA-MATIC 4T60-E SERVICEABLE COMPONENTS:

Part Illustration Number Number Description ---------- ------------- ------------------------- 08666007 4 Seal, Assembly - Axle Oil *11509041 9 Bolt (Speed Sensor) *10456034 10 Speed Sensor Assembly *11508600 12 Bolt (Forward Servo Cover) *08651916 13 Forward Servo Cover *08651567 14 Seal O'Ring (Forward Servo Cover) *12337905 23 Bolt (Bottom Pan) *08651914 24 Transaxle Oil Pan *08676250 25 Transaxle Oil Pan Gasket (Gasket is Reusable Unless Damaged) 08676164 28 Ball Check Assembly 08651654 29 Cooler Pipe Fitting *11509511 30 Bolt (Modulator to Case) 08627650 31 Retainer Modulator 08662967 32 Modulator 10054241 33 Modulator O'Ring 08658375 34 Modulator Valve *08651620 35 Electrical Connector *08651621 36 Electrical Connector O'Ring 08656536 39 Retaining Ring *08651915 40 Reverse Servo Cover 08658111 41 Seal O'Ring (Reverse Servo) 08656394 50 Nut Flanged 08656395 51 Conical Washer 08656392 52 Screw & Conical Washer 08651472 53 Side Cover 08644902 54 and 55 Side Cover Gasket Kit *08651909 100 Filter Assembly 08656613 101 Seal Assembly Filter 08644637 409 Seal Assembly (Left Side Axle) 08664812 525 Seal Assembly (Converter)

IMPORTANT: Components noted with asterisk "*" are unique to the HYDRA-MATIC 4T60-E. Remaining components are common with the HYDRA-MATIC 4T60.

Parts are currently available from GMSPO.

SRTA PROCESSING PROCEDURE:

Each SRTA unit will be shipped in a container which must be used for core return of the original HYDRA-MATIC 4T60-E assembly. A SRTA information Packet is included with each SRTA unit. The contents of this envelope are to be removed and used as described with each illustration on the following pages.

SRTA PROCESSING PROCEDURES - INFORMATION PACKET

The contents of this envelope include Limited Warranty Information, Dealer Product Feedback Form, Core Exchange Return Procedure, and a pre-addressed return mailing envelope. A dealer representative is to explain to the customer all warranty information contained in this envelope.

SRTA PROCESSING PROCEDURES - CORE EXCHANGE RETURN:

The core return procedure provides detailed instructions for the GM dealer on handling the SRTA and original HYDRA-MATIC 4T60-E units. The shipping labels are included in the package of information that is included with every HYDRA-MATIC 4T60-E SRTA unit.

SRTA PROCESSING PROCEDURES - FAILURE ANALYSIS INFORMATION:

This Product Feedback Form is to be completed by the service manager and/or technician. Fill out this form as completely as possible to provide information which can be used for analysis. This valuable input can result in future product refinement through corrective action. Insert the white copy of the completed form and a copy of the repair order into the SRTA Information Packet envelope, reseal the envelope and wire tag it to the bell housing of the unit being returned for core exchange. Return the yellow copy of the completed Product Feedback form, using the postage paid envelope, to Hydra-matic Division.

HYDRA-MATIC 4T60-E TRANSAXLE IDENTIFICATION INFORMATION:

Transaxle identification information and the SRTA MODEL REPLACEMENT CHART will assist in selecting the correct SRTA unit to order from your local Parts Distribution Center.

HYDRA-MATIC 4T60-E SRTA MODEL REPLACEMENT CHART:

SRTA SRTA Model Part Description ----- ------- ------------------------------------------- 1CWW 8651961 3.4L Twin DOHC W-car 4T60-E Transaxle Model

PARTS INFORMATION:

Part numbers are accurate at the time of printing and subject to change. Refer to the latest GMSPO Parts Catalog for part numbers of SRTA models listed.

Part number 8651961 is expected to be available on 03-15-91. Until then normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the part will be shipped premium transportation at dealer's expense. All other order types will be canceled as incorrectly ordered while the 400 control is in place.

UPDATED SHIFT SPEED CHART: (Figure 7) -------------------------------------- Reference the updated shift speed chart when servicing a 1CWW model. (Please update your Service Manual accordingly)

NEW HIGH TORQUE GEAR SET: (Figures 8-10) ----------------------------------------- A new high torque gear set is used only in the 1 CWW model. This new gear set includes: a new input carrier, reaction carrier and final drive sun gear and final drive carrier. For this change to be implemented, the following parts were modified:

- New reaction carrier needles, pinions, pinion shafts and lube grooves added to the carrier to increase lubrication through the needles. The lubrication flows into the lube groove slots in the carrier between the washer and the carrier, then through the needles. This helps get lube to the needles under high torque situations. The identifier is a wide green band around the outside of the carrier.

- New input carrier needles, pinions, pinion shafts, washers and lube grooves added to the carrier to increase lubrication through the needles. There used to be a bronze and a steel washer on each side of each pinion. Now, there are two new steel washers on each side of the pinion that have three scallops or lube openings to help increase lube flow through needles. The identifier is a wide green band around the outside of the carrier.

- New final drive carrier and sun gear that have phosphate coated pinions and sun gear to reduce spalling and pitting under high torque situations. The identifier for the high torque 3.06 ratio final drive carrier is a blue dot and pink dot located on the carrier by one of the pinions. The final drive sun gear is a darker black than the standard 3.06 ratio sun gear.

NOTICE: Use only the new high torque gear set parts when servicing a 1CWW. Durability concerns could result if non-1CWW gear set parts are used. The new gear parts can service most previous model input and reaction carriers that have the wider sprag and lube dam. Reference Dealer Service Bulletin No. 86-258-7A. The new 3.06 sun gear and final drive carrier can service most previous 3.06 ratio models back into the 1988 model year. Reference Dealer Service Bulletin No. 88-289-7A.

SERVICE PARTS INFORMATION:

Part Number Description Model Usage ------- ------------------ ----------------------- 8679001 Carrier Assembly - 1CWW and other models Reaction Complete included under "NOTICE"

8679000 Carrier Assembly - 1CWW and other models Input Complete included under "NOTICE"

8651912 Carrier Assembly - 1CWW and other models Differential/Final Drive included under "NOTICE" Complete

8679567 Gear - Final Drive Sun 1CWW and other models included under "NOTICE"

Parts are expected to be available on 03-15-91. Until then normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the part will be shipped premium transportation at dealer's expense. All other order types will be canceled as incorrectly ordered while the 400 control is in place.

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.