This bulletin provides new product information for 1989 Hydra-Matic produced transaxles/transmissions.
THM 125C 2 - 5 THM 440-T4 6 - 23 THM 200-4R 24 - 28 THM 700-R4 29 - 36 THM 400-475 37 - 38
All Hydra-Matic applications for each assembly are included in this bulletin. some of the assemblies are not used in Chevrolet models.
TRANSAXLE: 1989 THM 125C VEHICLE LINE USAGE: CELEBRITY, CORSICA, BERETTA, CAVALIER
This section contains revised information for THM 125/125C transaxles in 1989 New Product Information Manuals, Preliminary Service Manuals and Service Manuals printed prior to October, 1988. This information will be in service Manuals printed after November, 1988.
Refer to this bulletin when use of the following information is necessary.
Transaxle Diagnosis (Figure 1) 1989 THM 125C Shift Speed Chart Transaxle Diagnosis (Figure 2) Preliminary Check Procedure (Fluid Pressure Check) Unit Repair Section (Figure 3) Control Valve and Oil Pump Assembly.
In Figure 3 a New Valve Bore Plug (382) has been added to some THM 125/125C models.
Changes in the Preliminary Check Procedure and Shift Speed Chart are due to some THM 125/125C models which were dropped and new models that were added as follows:
TRANSAXLE: 1989 THM 440-T4 VEHICLE LINE USAGE: CELEBRITY
This section contains New Product Information on all 1989 model THM 440-T4 and THM F-7 transaxles. The information contained in this bulletin describes changes that occurred at the Start Of Production (SOP) for 1989 THM 440-T4 and THM F-7 transaxles. Refer to each section of this bulletin for specific product change information.
DATE OF PRODUCTION CHANGE: (Figure 1) ------------------------- At the Start of Production, 1989 THM 440-T4 and THM F-7 transaxles were produced with the product changes listed in this bulletin.
Refer to the Transaxle Hydraulic Diagnosis and Transaxle Unit Repair sections in your 1989 Service Manual for changes shown in this bulletin.
TRANSAXLE APPLICATIONS: SUBJECT:
1989 THM F-7 (ME9) New 1-2 Servo Apply Pin Selection Chart
TRANSAXLE MODELS: AXH VEHICLE APPLICATIONS: V Car
CHANGE TO ASSEMBLY COMPONENT: (Figure 2)
The 1-2 servo apply pin (561) selection chart has been changed for the 1989 model year to eliminate the two shortest of the selection set while adding two longer selections. The 1989 THM F-7 Transaxle calibration requires a new selection set.
When servicing a past model THM F-7 transaxle use the proper year 1-2 servo apply pin selection chart.
Reference new 1-2 servo apply pin selection chart, Figure 2.
This product change information is shown in the THM F-7 Automatic Transaxle Unit Repair section of your 1989 Service Manual.
TRANSAXLE APPLICATIONS: SUBJECT:
1989 THM 440-T4 (ME9) New Reverse Servo Apply Pin 1989 THM F-7 (ME9) Selection Chart
TRANSAXLE MODELS: VEHICLE APPLICATIONS:
All THM 440-T4 Models A, C, H, E, K, W, Z Cars THM F-7 - AXH VCar
CHANGE TO ASSEMBLY COMPONENT: (Figure 3) ---------------------------- The reverse servo apply pin (551) selection chart has been changed for the 1989 model year to eliminate the longest and the two shortest of the selection set. The 1989 transaxle calibrations require a new selection set for the THM 440-T4 and THM F-7 Transaxles.
When servicing a past model THM 440-T4 or THM F-7 transaxle use the proper year servo apply pin selection chart.
Reference new reverse servo apply pin selection chart, Figure 3.
This product change informaiton is shown in the THM 440-T4 and THM F-7 Automatic Transaxle Unit Repair section of your 1989 Service Manual.
TRANSAXLE APPLICATIONS: SUBJECT:
1989 THM 440-T4 (ME9) 10 Plate 3rd Clutch Pack 1989 THM F-7 (ME9)
TRANSAXLE MODELS: VEHICLE APPLICATIONS:
All THM 440-T4 A, C, H, E, K, W, Z Cars THM F-7 - AXH VCar
CHANGE TO ASSEMBLY COMPONENT: (Figures 4, 5, 6, 7, 8, 9 and 10) ---------------------------- A new 10 plate 3rd clutch pack (640) is used to replace the 8 plate 3rd clutch pack for all 1989 THM 440-T4 and THM F-7 transaxles. The two extra plates were added for new higher torque engine applications.
For this change to be implemented the following parts were modified:
- 3rd clutch plate (fiber one side) I.D. and O.D. splines, (Figure 5) are thinner by 0.15mm (0.006"). The fiber material is the same thickness only the steel part of the plate was made thinner.
- Input clutch piston (630) cutouts for the 3rd clutch plates are 6.35mm (0.25") deeper so the piston travel will clear the increased thickness of the 3rd clutch plate pack. (Figure 6)
- 3rd clutch piston housing (633) has decreased in overall size. (Figure 7)
- 3rd clutch piston (637) seal (635) is now molded to the piston (802) (Figure 8).
- 3rd roller clutch outer race (645) is wider by 0.83mm (0.033") to accommodate the two extra plates. (Figure 9) Note: The rollers have not changed in width.
- 3rd clutch spring retainer and guide assembly (638) cutout is 1.1mm (0.043") deeper for 1989. This allows sufficient clearance for the relocated retainer and ball assembly that is part of the new 3rd clutch piston seal assembly and retainer and ball assembly (8 02) . (Figure 10)
When servicing a 1984 through 1988 THM 440-T4 or THM F-7 transaxle you must use the previous 3rd clutch pack assembly as shown in the Service Parts Information section below. DO NOT interchange individual components with previous model years or a misbuild will occur. The 1989 input clutch apply piston assembly (630) and 1989 3rd clutch spring retainer and guide assembly (638) are the only components of the 10 plate 3rd clutch pack that can service prior model years.
Part No. Description Model Yr - Model Usage ------- ----------- -------------------------- 8662927 Plates, 3rd Clutch (fiber 1988 8AAH, 8ABH, 8AFH, one side with wave plate) 8AJH, 8ANH, 8ATH, (8 plates) (640) 8CFH, 8CMH, 8GRH, 8CTH, 8CWH, 8CXH
8646938 Plates, 3rd Clutch (fiber 1987-88 All 87 models, one side) (8 plates) (640) 8BJH, 8BKH, 8BRH, 8BTH, 8BYH, 8FBH, 8FCH, 8FJH, 8FSH, 8VXH
8662954 Plates, 3rd Clutch (fiber 1989-All Models one side with wave plate) (10 plates) (640)
Parts (listed above) are currently available from GMSPO.
8668295 Piston Asm. Input Clutch 1984-89 All Models Apply (630)
Parts are expected to be available (for part number 8668295) on 10/24/88. 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 cancelled as incorrectly ordered while the 400 control is in place.
8656310 Housing, 3rd Clutch 1984-88 All Models Piston (633) 8668359 Housing, 3rd Clutch 1989 All Models Piston (633) 8644919 Piston, 3rd Clutch (637) 1984-88 All Models 8668453 Seal Asm. and Retainer and 1989 All Models Ball Asm., 3rd Clutch Piston (802) 8662676 Roller Asm. Comp. - 3rd 1984-88 All Models Clutch (645) 8668367 Roller Asm. Comp. - 3rd 1989 All Models Clutch (645) 8662674 spring Retainer and Guide 1984-88 All Models Asm. - 3rd Clutch 8668071 spring Retainer and Guide 1984-89 All Models Asm. - 3rd Clutch
Parts are currently available from GMSPO.
This product change information is shown in the THM 440-T4 and THM F-7 Automatic Transaxle Unit Repair section of your 1989 service Manual.
The 3rd clutch wave plate (800) (was 640A for 1988) is standard on all 1989 vehicles equipped with a THM 440-T4 or a THM F-7. The wave plate (640A) for 1988 was only used on vehicles equipped with 2.8L, 4.lL or 4.5L engines.
TRANSAXLE APPLICATIONS: SUBJECT:
1989 THM 440-T4 (ME9) One Piece Channel Plate Gasket 1989 THM F-7 (ME9)
TRANSAXLE MODELS: VEHICLE APPLICATIONS:
All THM 440-T4 A, C, H, E, K, W, Z Cars THM F-7 - AXH V Cars
CHANGE TO ASSEMBLY COMPONENTS: (Figure 11) ----------------------------- A new one piece channel plate (upper) gasket (801) is used to replace the channel plate (upper) gasket (409) and modulator port gasket (415). The one piece design ensures that the gasket does not become mispositioned upon assembly of the channel plate.
When servicing a past model (built after 1985-1/2) use the new one piece channel plate (upper) gasket. The one piece channel plate (upper) gasket will service all past models back to 1985-1/2. Transaxles built before 1985-1/2 must still use the two piece channel plate gasket.
Part No. Description Model Year - Model Usage -------- ----------- ------------------------ 8646945 Gasket, Channel Plate 1985-1/2-89 - All (one piece upper/lower) 8646908 Gasket,Channel Plate 1984-85-1/2 - All (two piece upper/lower)
Parts are currently available from GMSPO.
This product change information is shown in the THM 440-T4 and THM F-7 Automatic Transaxle Unit Repair section of the 1989 Service Manual.
This change was implemented into some models late in the 1988 model year.
TRANSAXLE APPLICATIONS: SUBJECT:
1989 THM F-7 Elimination of the 3rd and 4th Clutch Apply Pressure Switches- Requires a New Wiring Diagram
TRANSAXLE MODELS: AXH VEHICLE APPLICATIONS: V Cars
CHANGE TO ASSEMBLY COMPONENTS: (Figure 12) ----------------------------- A 2nd clutch switch (normally closed switch) is used on the THM F-7 Transaxle with the elimination of the 3rd and 4th clutch apply pressure switches. The 3rd and 4th gear selection is now calculated through the ECM using vehicle speed and engine RPM. The 2nd clutch switch is used to signal the ECM that the 2nd clutch pack has sufficient pressure (689.5 kPa (100 PSI)) for a 3-2 downshift.
When servicing a 1989 AXH model THM F-7 transaxle use the parts listed in the Service Parts Information section below. Also note in the wiring diagram (Figure 12) that PIN "B" of the electrical connector is not functional.
Part No. Description Model Year - Model Usage ------- ----------- ------------------------- 8668146 Harness Assembly, Wiring 1989 - AXH
Parts are currently available from GMSPO.
This product change information is shown in the THM F-7 Automatic Transaxle Unit Repair section of your 1989 Service Manual.
TRANSAXLE APPLICATIONS: SUBJECT:
1989 THM 440-T4 (ME9) New Backing Plate and Snap 1989 THM F-7 (NE9) Ring for 2nd Clutch Pack
TRANSAXLE MODELS: VEHICLE APPLICATIONS:
All THM 440-T4 A, C, H, E, K, W, Z Cars THM F-7 - AXH VCar
CHANGE TO ASSEMBLY COMPONENTS: (Figure 13) ----------------------------- A new shorter 2nd clutch backing plate that eliminates the groove and cutouts for the snap ring, replaces the previous 2nd clutch backing plate and snap ring. A new snap ring that is about half as wide as the previous model year must be used with the new backing plate.
The THM F-7 started using the new backing plate and snap ring at Start Of Production (SOP) 1989.
The THM 440-T4 started using the new backing plate and snap ring on August 22, 1988 (Julian Date 235).
DO NOT service the new backing plate (619) and snap ring (620) into a prior year 2nd clutch. This may cause the backing plate to crack if the new 2nd clutch backing plate is used with the old (non chamfered) reaction drum and/or an engine without torque management.
Part No. Description Model Year-Model Usage -------- ----------- ------------------------ 8668566 Plate, Backing Support Ring 1989 - All 8668567 Ring, Snap 1989 - All
Parts are expected to be available (for part numbers 8668566 and 86685 67) on 11/21/88. 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 cancelled as incorrectly ordered while the 400 control is in place.
8662010 Plate, Backing Support Ring 1987-88 - All 8661141 Ring, Snap 1987-88 - All
Parts are currently available from GMSPO.
This product change does not affect diagnosis for 1989 THM 440-T4 or the THM F-7 transaxles and is not shown in the 1989 THM 440-T4 or the THM F-7 Unit Repair Section of your Service Manual.
TRANSAXLE APPLICATIONS: SUBJECT:
1989 THM 440-T4 (ME9) New Shift Speed and Oil 1989 THM F-7 (ME9) Pressure Charts
TRANSAXLE MODELS: VEHICLE APPLICATIONS:
All THM 440-T4 A, C, H, E, K, W, Z Cars THM F-7 - AXH VCar
CHANGE TO ASSEMBLY COMPONENTS: (Figures 14, 15, 16 and 17) ------------------------------ Shift speed and oil pressure charts for the 1989 model year have been changed for new engine calibrations and the addition of three 1989 THM 440-T4 transaxle models.
Reference the new shift speed and oil pressure charts when servicing a 1989 model.
This product change information is shown in the THM 440-T4 and THM F-7 Automatic Transaxle Unit Repair section of your 1989 Service Manual.
TRANSMISSION: 1989 THM 200-4R VEHICLE LINE USAGE: CAPRICE
This section contains New Product Information for all 1989 THM 200-4R transmissions. The information contained in this bulletin describes changes that have occurred in the 1989 THM 200-4R transmission. Refer to each section of this bulletin for specific product change information.
DATE OF PRODUCTION CHANGE: (Figure 1) ------------------------- Beginning with 1989 Start of Production, all 1989 THM 200-4R transmissions were built with the product changes explained in this bulletin.
Changes listed in this bulletin as "Service Manual Update" will note changes made since publication of the 1989 Service Manual and should be noted in your 1989 Service Manual accordingly.
Other changes described in this bulletin are included in your 1989 THM 200-4R Service Manual sections. Be certain to familiarize yourself with these changes to properly service the 1989 THM 200-4R transmission.
This information (Figures2 and 3) has been updated since publication of the 1989 service Manual. Use this information to update the 1989 THM 200-4R Automatic Transmission Diagnosis section.
TRANSMISSION MODELS: CTF, CUF
Beginning with the 1989 model year the CTF and CUF 200-4R models were built with a new solenoid assembly (refer to Figure 4). The new solenoid assembly no longer uses the 4-3 pulse switch. The new solenoid assembly, listed under "Service Parts Information", should be used when servicing any 1989 CTF or CUF models.
Part No. Description
8639961 Solenoid Assembly - CTF and CUF Models
Parts are currently available from GMSPO.
This information is included in the 1989 THM 200-4R Automatic Transmission Diagnosis Section.
TRANSMISSION: 1989 THM 700-R4 VEHICLE LINE USAGE: CAPRICE, CAMARO, CORVETTE, C, K, R, V, S, T, G AND M VAN
This section contains New Product Information for all 1989 THM 700-R4 transmissions. Refer to each section of this bulletin for specific product change information.
DATE OF PRODUCTION CHANGE: (Figure 1) ------------------------- Beginning with 1989 Start of Production, all 1989 THM 700-R4 transmissions were built with the product changes explained in this bulletin.
Changes listed in this bulletin as "Service Manual Update" will note changes made since publication of the 1989 Service Manual and should be noted in your 1989 Service Manual accordingly.
Other changes described in this bulletin are included in your 1989 THM 700-R4 Service Manual sections. Be certain to familiarize yourself with these changes to properly service the 1989 THM 700-R4 transmission.
CHANGE TO ASSEMBLY COMPONENTS: (Figure 2) ----------------------------- A new Input Clutch Assembly with 3-4 clutch boost springs (600) introduced for all 1989 THM 700-R4 models. (This Input Clutch Assembly and 3-4 clutch boost springs were first used in the 1988 model year on the YDM, YMM, YMM and YZM models; reference Dealer Service Bulletin 88-115-7A dated February, 1988. The boost springs aid the release of the 3-4 clutch on downshifts.
When servicing any 1989 THM 700-R4 transmission, the 3-4 clutch boost springs must be used. Improper shift timing can occur if these springs are not installed. When overhauling the 3-4 clutch assembly, the 3-4 clutch boost springs should be inserted in place after installation of the 3-4 clutch plates, just prior to installing the 3-4 clutch backing plate and snap ring.
Part No. Description 8667424 Spring Asm, Boost 3-4 Clutch (600) - (5 required)
Parts are currently available from GMSPO.
This information is included in your 1989 Service Manual Unit Repair Section. Information that is new for 1989 is noted by an asterisk in the Unit Repair Table of Contents.
This information (Figures 3 and 4) has been updated since publication of the 1989 Service Manual. Use this information to update your 1989 THM 700-R4 Automatic Transmission Diagnosis Section.
CHANGE TO ASSEMBLY COMPONENTS: (Figures 5-7) --------------------------------- Beginning with the 1989 model year, the FMM model THM 700-R4 transmission uses a Type 18 Solenoid Assembly and Wiring Harness (refer to Figure 5). The Type 18 Solenoid Assembly and Wiring Harness was introduced late in the 1988 model year and replaced most Type 15 Solenoid Assembly production reference Dealer Service Bulletin 88-335-7A dated September, 1988. The FMM model is the last Type 15 Solenoid Assembly model to change to Type 18 usage. Also for 1989 is the addition of two new solenoid assemblies, Type 19 Solenoid Assembly and Wiring Harness and Type 21 Solenoid Assembly and Wiring Harness (refer to Figures 5 and 7). Both the Type 19 and Type 21 Solenoid Assemblies were introduced on their respective models at 1989 start of production.
Part No. Description
10478100 Type 18 Solenoid Assembly - Complete
Parts are expected to be available on 12/05/88. 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 cancelled as incorrectly ordered while the 400 control is in place.
10478101 Type 19 Solenoid Assembly - Complete
Parts are currently available from GMSPO.
10478150 Type 21 Solenoid Assembly - Complete
The Type 21 Solenoid Assembly is a General Motors - Holden application only.
This information (Figures 5-7) has been updated since publication of the 1989 Service Manual. Use this information to update your 1989 THM 700-R4 Automatic Transmission Diagnosis Section.
TRANSMISSION: 1989 THM 400/475 VEHICLE LINE USAGE: TRUCKS
This section contains New Product Information for all 1989 THM 400/475 Hydra-Matic 3L80/3L80-HD Transmissions. The information contained in this bulletin describes changes that have been implemented in the 1989 THM 400/475, Hydra-Matic 3L8O/3L80-HD Transmissions. Refer to each section of this bulletin for specific product change information.
DATE OF PRODUCTION CHANGE: (Figure 1) ------------------------- Beginning with the Start of Production 1989, all 1989 THM 400/475, Hydra-Matic 3L80/3L80-HD Transmissions were built with the product changes explained in this bulletin.
Product changes in this bulletin are included in your 1989 THM 400/475, Hydra-Matic 3LSO/3L80-HD Service Manual Sections.
SERVICE MANUAL REFERENCE: (Figure 2) ------------------------ This information is an update to your 1989 Service Manual Transmission Diagnosis Section. A new model, DNA, was released after publication date.
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.