SERVICE AND PARTS INFORMATION 700R4 WITH/W/O AUX VALVE BODY

1987 SAFARI WAGON AND FIREBIRD MODELS EQUIPPED WITH THM 700-R4 (MD8)

A 1987 model THM 700-R4 transmission may be built with or without an auxiliary control valve assembmly (AUX V/B). Identification, service procedures, new parts and fluid passage information for this change are provided in this bulletin.

IMPORTANT: The 1987 GM Service Parts Catalog printed in September, 1986 gives information for a 1987 transmission built with an AUX V/B. Use of this printed information on a transmission built without an AUX V/B can create a misbuild,

Additionally, other changes to the 1987 THM 700-R4 transmission that affect service procedures and/or new part information are also included.

Date Of Changes

By October 6, 1986, (Julian Date 279) all 1987 THM 700-R4 transmission models were built with the AUX V/B. Also, all 1987 Service Replacement Transmission Assembly (SRTA) models are built with the AUX VIB (refer to Figure 1).

Service Action

To determine which service procedures and parts to use on a 1987 THM 700-R4 assembly with a Julian Date between 198 and 279, remove the transmission oil pan and look for an auxiliary valve body (refer to Figure 2).

Service Parts Information

If the auxiliary valve body is present, refer to 1987 GMSPO Catalog Listing dated September, 1986.

If the auxiliary valve body is not present, refer to GM Service Parts "Action" Bulletin #86-58.

Service Manual Reference

1987 Service Manual procedures and illustrations in manuals printed prior to November, 1986 may not include information provided in this bulletin.

SUMMARY OF BULLETIN INFORMATION

DETAILS BEFORE AFTER ON DATE OF DATE OF SUBJECT PAGE CHANGE CHANGE ------- ------- ------- ------ Auxiliary Control Valve 4 Not Used Used Assembly Scarf Cut Solid -- turbine shaft seals

Fluid Passage Identification 8-15 ------ ------

Oil Pump Assembly 16 7 Vane 10 Vane Plugged Holp Add Feed Pipe

Forward Clutch Assembly 18 Stack Up: Stack Up: thick spacer no spacer and thin apply or thin apply narrow sprag: wider sprag: wear plate no wear plate thrust washer no thrust washer

Lo And Reverse Roller Clutch 22 Used Pre-SOP Wider Roller 1987 Models Elements

Oil Pan 23 Round Magnet Square Magnet Dimpled Pan Deeper Pan

SUBJECT ------- NEW AUXILIARY VALVE BODY ASSEMBLY

TRANSMISSION MODELS

ALL MODELS

Change To Assembly Components

- New auxiliary valve body assembly with the following components (Figures 3 and 6) :

-- lo overrun clutch valve (364) and spring (365) -- abuse valve (360) and spring (361) -- orificed cup plug (359) -- accumulator piston (367) and spring (370) -- #5 checkball (used in the valve body on 1982 through early 1987 models, Figures 3 and 5) -- tube (96) from pump cover to auxiliary valve body (Figures 6 and 8)

Major Components Changed With Addition Of New Auxiliary Valve Body Assembly

- Cup plug (244) eliminated from pump cover (Figure 19)

-- tube (96) is used in this bore

- New input housing assembly (621) with solid turbine shaft seals (619) (Figure 7)

-- scarf cut seals MUST NOT be used in place of solid seals -- 6mm forward clutch feed hole in turbine shaft (Figure 7)

- New spacer plate (56) and gaskets (88 and 89) (Figure 6)

- New case assembly (10) (Figure 6)

-- rib added to lo/reverse passage under auxiliary valve body -- (Figure 4) new orificed lube hole near governor bore in case

- New control valve assembly (67) (Figure 6)

-- not interchangeable on transmissions without an auxiliary valve body

Date Of Change

October 6, 1986, Julian Date 279, for all 1987 THM 700-R4 transmission models. All 1987 Service Replacement Transmission Assemblies (SRTA) models have the new auxiliary valve body assembly.

Service Action

IMPORTANT: THE "MAJOR COMPONENTS CHANGED" LISTED ON PAGE 4 CANNOT BE USED TO SERVICE 1982 THROUGH 1987 TRANSMISSIONS THAT DO NOT HAVE AN AUXILIARY VALVE BODY.

- When using a new pump cover (see page 16) for a transmission with an auxiliary valve body, cup plug (244) must be removed.

- When replacing a case assembly on a 1987 transmission, inspect the new case for a rib in the lo/reverse passage (Figure 4).

-- if rib is present: use only on models with an auxiliary valve body

- When servicing the turbine shaft sLeals (619) do not use scarf cut seals on a transmission with an auxiliary valve body. (See "Service Parts" section below).

-- use installation tool (J 36418-1) and sizing tool (J 36418-2) for solid turbine shaft seals (Figure 7)

- Input housing and shaft assemblies (621) used on transmissions with an auxiliary valve body are not interchangeable with previous model year transmissions.

Service Parts

Four input housing and turbine shaft assemblies are available for 1987 model transmissions:

Part Number Description ----------- -----------

8657901 -298 mm turbine shaft and input housing with scarf cut seals (for a transmission without an auxiliary valve body)

8657902 - 245mm turbine shaft and input housing with scarf cut seals (for atransmission without an auxiliary valve body)

8657903 - 245mm turbine shaft and input housing with solid seals (for a transmission with an auxiliary valve body)

8657904 - 298mm turbine shaft and input housing with solid seals (for a transmission with an auxiliary valve body)

Six transmission case assemblies are available for 1987 model transmissions:

Part Number Description

*8648992 - Case Assembly Complete (for a transmission without an auxiliary valve body)

*8648993 - Case Assembly Complete (for a transmission without an auxiliary valve body)

*8648994 - Case Assembly Complete (for a transmission without an auxiliary valve body)

*8648902 - Case Assembly Complete (for a transmission with an auxiliary valve body)

*8648904 - Case Assembly Complete (for a transmission with an auxiliary valve body)

*8648905 - Case Assembly Complete (for a transmission with an auxiliary valve body)

*SEE SERVICE PARTS LIST FOR MODEL APPLICATION

SUBJECT ------- FLUID PASSAGE IDENTIFICATION CHANGES

TRANSMISSION MODELS

ALL MODELS WITH AUXILIARY VALVE BODY

Change to Assembly Components

Revised fluid passages in the following components:

- Valve Body (Figure 9) - Spacer Plate to Valve Body Gasket (Figure 10) - Spacer Plate (Figure 11) - Spacer Plate to Case Gasket (Figure 12) - Case Oil Passages (Figure 13) - Pump to Case Oil Passages (Figure 14) - Servo Oil Passages (Figure 15) - Pump Cover Oil Passages (Figure 16) - Pump Body Oil Passages (Figure 17) - Hydraulic Schematic of "Park" (Figure 18)

Date Of Change

October 6, 1986, Julian Date 279, for all 1987 THM 700-R4 transmission models. All 1987 Service Replacement Transmission Assemblies (SRTA) models have the new auxiliary valve body assembly.

Service Action

Use illustrations provided in this bulletin for identifying/diagnosing a 1987 THM 700-R4 transmission without an auxiliary valve body.

Use 1987 Service Manuals printed prior to November, 1986 for identifying/diagnosing a 1987 THM 700-R4 transmission without an auxiliary valve body.

SUBJECT ------- NEW OIL PUMP ASSEMBLY

TRANSMISSION MODELS

ALL MODELS

Change To Assembly Components

- Increase of 3 pump vanes, from 7 to 10 vanes (215, Figure 19)

- New oil pump rotor (214) and rotor guide (213) to accommodate additional vanes.

- Elimination of cup plug (244) on models using an auxiliary valve body assembly (see information contained in this Bulletin on page 4 "Major Component Changed" section).

Date Of Change

October 28, 1986, Julian Date 301, for all 1987 THM 700-R4 transmission models. During the production of 1986 and early 1987 models, up to November 10, 1986, only some transmission assemblies used the 10 vane assembly. All 1987 Service Replacement Transmission Assemblies (SRTA) models have the new oil pump assembly.

Service Action

When using the new pump cover (217) inspect for cup plug (244). Cup plug must be present for transmissions not using an auxiliary valve body. The cup plug should be removed for assembly of feed tube (96) on transmissions that use an auxiliary valve body.

Service Parts Information

Part Number Description ----------- ----------- 8649964 Pump Body Assembly Complete (1985-1987 models)

8649951- Selective Vane Ring Packages (all models, all years) 8649955

8649950 Pump Body Assembly Complete (1985-1986 models) (These pump bodies are to be used until stock is depleted unless noise condition is exhibited)

Note:The pump body and pump cover assemblies used on 1982 through 1984 transmission are NOT serviced separately.

SUBJECT ------- NEW FORWARD CLUTCH ASSEMBLY

TRANSMISSION MODELS

ALL MODELS

Change To Assembly Components

- New clutch plate stack up for all models (Figures 20 and 21)

-- 5steel plates (649) -- 5 composition plates (649) -- 1 apply plate (646) -- 1 waved steel plate (648) -- 1selective backing plate (650, Figures 21 and 22)

NOTE: Eliminate forward clutch spacer plate (647) and thin apply plate (646)

- New forward clutch sprag assembly (Figures 23 and 24)

-- increase of 2 elements (total of 28 elements) -- larger inside diameter of sprag outer race (644) -- larger outside diameter of sprag retainer and race assembly -- ( 6 4 1 ) new retainer rings (643) for sprag elements

- New overrun clutch hub (639) due to elimination of:

-- sprag assembly wear plate (640) -- thrust washer (input carrier/sprag) (660)

Date Of Change

July 17, 1986, Julian Date 198, for all 1987 THM 700-R4 transmission models. All 1987 Service Replacement Transmission Assemblies (SRTA) models have the new forward clutch assembly.

Service Action

Component parts of the new sprag are not serviced separately. When using the new sprag, race, and hub assembly on 1982 through 1986 THM 700-R4 transmissions, the sprag assembly wear plate (640) and input carrier to race thrust washer (660) must be removed and not used.

NOTE: If transmission has AUX V/B, solid turbine shaft seals must be used.

Service Parts Information

Part Number Description ----------- ----------- 8663773 Sprag, Race and Hub Assembly (1987 YAM, YCM, YDM, YMM, YSM, YWM, YZM, models only)

8663774 Sprag, Race and Hub Assembly (All other 1987 models)

SUBJECT ------- NEW LO AND REVERSE ROLLER CLUTCH ASSEMBLY

TRANSMISSION MODELS

ALL MODELS

Change To Assembly Components

- .150" (3.81mm) wider roller elements for assembly (678, Figure 25)

Date Of Change

June 19, 1986, Julian Date 170 for late 1986 model year production transmissions. All 1987 production and Service Replacement Trans- mission Assembly (SRTA) models have the new lo and reverse roller clutch assembly.

Service Action

When servicing a lo and reverse roller clutch on a 1986 or 1987 model transmission only use the new service kit assembly 8663094. Components 675, 677, 678 and 679 (Figure 25) were serviced individually for all 1982 through 1985 model transmissions. Do not use these individual components (included in service kit 8663094) to service a 1986 or 1987 model transmission.

Service Parts Information

Part Number Description ----------- ----------- 8663094 Lo and Reverse Roller Clutch and Support Assembly (1982- 1987 models)

SUBJECT ------- NEW OIL PAN AND MAGNET

TRANSMISSION MODELS

ALL MODELS

Change To Assembly Components

- Oil pan (73, Figure 26) is lmm deeper (to accommodate auxiliary valve body) - New square, flexible chip collector magnet (93)

Date Of Change

July 17, 1986, Julian Date 198, for all 1987 THM 700-R4 transmissions. All 1987 Service Replacement Transmission Assembly (STRA) models have the new oil pan and magnet.

Service Action

When servicing a 1987 model transmission, only use the new pan and magnet.

Service Parts

Part Number Description Model Year Usage ----------- ----------- ---------------- 8654700 Transmission Oil Pan 1982 through 1986 8663618 Transmission Oil Pan 1987 Only

NOTE: When current stock for 1982-1986 is used up, new pan and magnet will service 1982-1987 transmissions.

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.