A/T - Changes for 1986

SIL 86-18 (Aug)

SUBJECT: 1986 MODEL YEAR CHANGES RWD Courtesy Chrysler Corp.

PART THROTTLE UNLOCK (A904)

Part throttle unlock feature was incorporated in all 318(A999) and 225(A904T) truck transmissions with lockup. Performance is improved by unlocking the torque converter with application of heavy throttle at speeds up to 50 MPH. Lockup and unlock points are computer controlled by sensing road speed, engine vacuum and engine temperature.

Addition of a solenoid in the valve body assembly required changes to the valve body, steel plate, transfer plate, throttle pressure adjusting bracket, case and reverse band lever. Following is a description of the parts that changed.

CASE - Threaded hole added in rear face for solenoid connector. Casting revision in accumulator bore area to provide clearance for solenoid. The new cases can be used to service prior models by plugging connector hole with P/N 6028873 plug.

New P/N Old P/N
Case Assy. 4202767 4130977 318 Engine
Case Assy. 4202768 4202047 225 Engine

TRANSFER PLATE
Hydraulic passages revised and bore added for the solenoid. Tapped hole for attaching solenoid also added. New part used only with part throttle unlock assemblies.

STEEL PLATES
Orifice added and provisions added for P/T unlock solenoid. Used only with P/T unlock.

TP ADJUSTING BRACKET
Redesigned for added strength. Can be used in prior model valve body assemblies except those used in MMC transmissions.

New P/N Old P/N
4348882 3743840

VALVE BODY
Hydraulic passages revised to provide control circuit to P/T unlock solenoid. New valve body is not interchangeable with old part. However, In conjunction with new steel plates, it will be used in regular lockup and non-lockup valve bodies for production and service.

New V/Body Assys. Old V/Body Assy.
4348757 ------- P/T Unlock (225)
4348760 ------- P/T Unlock (318)
4348762 ------- Non Lockup
4348759 4202634 Regular Lockup
4348765 4269125 Non Lockup
4348964 4295888 Regular Lockup
4412488 ------- Regular Lockup
4348763 4202633 Non Lockup
4348764 4295863 Regular Lockup
4348965 4202631 Non Lockup
4348961 4202578 Regular Lockup
4348962 4202876 Regular Lockup
4348774 4269151 MMC Non Lockup
4348963 4202636 Regular Lockup
4348940 4295894 Non Lockup
4348773 4202875 Regular Lockup
4348772 4202632 Regular Lockup

SOLENOID ASSEMBLY
New part added. P/N 4348719

SOLENOID CONNECTOR
New part added. P/N 4348945

LOCKUP BODY
Hydraulic passages revised. New body will be used with regular lockup and past model service.

LOCKUP SPRING
New 4.0 # spring for P/T unlock only.

REVERSE BAND LEVER
Cast and machining changes to provide clearance for solenoid. New lever will service prior models.

New P/N Old P/N
4202764 2801815 Lever Assembly

HEAVY DUTY EXTENSION (A999 & A904T)

New extension was released for use in long wheelbase trucks. The bearing access hole was rotated 90°, flange thickness increased, and ribs added to Increase strength. The new heavy duty part can be used in place of regular extension in trucks.

New P/N Old P/N
Extension 4329883 3681600
Est. Assembly 4329882 3681599

TRANSMISSION ASSEMBLY (A904T)

As the A727 transmission will not be used with 225 6-cylinder truck engine in 1986, a new non-lockup transmission was released for California usage. Valve body assembly requires a new steel plate P/N 4348702, and uses lockup body (without valves) P/N 4348863 as a stiffener Instead of flat plate P/N 3410380.

"XJ" JEEP CASE (A904)

Case modified by adding a cast slot and two reamed holes for attaching Renix timing probe. The new case will be used to service prior models.

New P/N Old P/N
Case 4348603 4269738
Case Assembly 4348840 4295866

"YJ" JEEP TRANSMISSION (A999)

New transmission for "YJ" Jeep usage with 258 (4.2L) engine. Same as used with "CJ" and "SJ" Jeep except for Eagle adapter P/N 4269952.

CASE (A727)

Depth of three 7/16-14 holes at bottom of A-engine bell increased to permit use of longer strut bolts. New case will service prior models.

New P/N Old P/N
Case 4377912 4130190
Case Assembly 4377913 4130379

318 PASSENGER CAR TRANSMISSION (A999)

Lockup speed decreased in units used with 2.2 axle ratio in passenger cars. New valve body assembly P/N 4412488 to replace P/N 4295888 for this application. Transmissions and valve bodies are not interchangeable.