Town & Country Van V6-201 3.3L VIN R SMFI (1990)
Technical Service Bulletin # 212590A
Date: 901231
A/T - A604 Low Temperature Transmission Failure
SUBJECT:
Low Temperature
Transmission Failure - A604 Transmissions
NO.:
21-25-90 REV. A
GROUP:
TRANSMISSION
DATE:
Dec. 31, 1990
MODELS:
1990
(AC) DYNASTY/NEW YORKER LANDAU/SALON
(AY) IMPERIAL/NEW YORKER FIFTH AVENUE (AS) CARAVAN/GRAND CARAVAN/CARAVAN C/V
VOYAGER/GRAND VOYAGER (EQUIPPED WITH HEAVY DUTY TRAILER TOW) TOWN & COUNTRY
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN # 21-25-90 WHICH CONTAINED A TYPOGRAPHICAL ERROR AS
INDICATED BY >> << ARROWS. PLEASE DISCARD PAGE 1 AND 2 OF THIS BULLETIN AND INSERT THIS NEW PAGE.
NOTE:
TECHNICAL SERVICE BULLETIN >> # 21-28-89 << PROVIDED INSTRUCTIONS TO CORRECT THE SUBJECT
CONDITION ON CERTAIN 1988 AND 1989 MODEL YEAR VEHICLES. THIS BULLETIN IS BEING ISSUED TO
INCLUDE THE ABOVE 1990 MODEL YEAR VEHICLES.
SYMPTOM/CONDITION:
Under certain extremely cold ambient operating temperatures (-20~ F or colder), automatic transmission fluid may get cold enough to resist flow through
the transmission oil cooler mounted in front of the engine radiator. The transmission may fail due to lack of lubrication from the restriction if the vehicle
is driven long distances at highway speeds.
Diagnosis:
This modification should be performed on the subject vehicles that are known to be operating under the above described conditions. Also, the
modification should be performed on vehicles that experience transmission failures suspected to be the result of a restricted oil flow at extreme cold
ambient conditions. (Lack of lubrication)
Parts Required:
1
Pressure actuated cooler bypass valve package
PN 5252836
1
Bracket (for AS Body only)
PN 4333568
Repair Procedure:
This repair involves the installation of a pressure actuated bypass valve that will bypass the transmission cooler if it becomes restricted.
Figure 1
NOTE:
THE BYPASS VALVE IS DIRECTIONAL, IF IT IS NOT CONNECTED TO THE TRANSMISSION OIL COOLER HOSES IN THE
CORRECT OIL FLOW DIRECTION --- THE BYPASS VALVE WILL NOT FUNCTION. FIGURE 1.