B350 1 Ton Van V8-5.9L VIN Z (1992)
Transmission Cooler: All Technical Service Bulletins
A/T - Cooler Bypass Kit
NO: 21-01-96
GROUP: Transmission
DATE: Jan. 26, 1996
SUBJECT: RWD Automatic Transmission Oil Cooler Cold Temperature Bypass Kit
MODELS: 1989 - 1993 (AB) Ram Van/wagon
1989 - 1993 (AN) Dakota
1989 - 1993 (AD) Ram Pickup
1993 (ZJ) Grand Cherokee
SYMPTOM/CONDITION:
At ambient temperatures of -15 degrees F or below, vehicles equipped with a four speed automatic transmission and auxiliary transmission cooler may
experience a lack of transmission fluid flow to the transmission. At these low temperatures, the automatic transmission fluid might freeze in the
transmission oil cooler lines restricting fluid flow. This can cause damage to the transmission, and in periods of extended driving, transmission failure
may result.
DIAGNOSIS:
The cold weather by-pass kit should be installed if any of the following conditions are met:
1.
If the vehicle is used in areas of extended cold ambient temperatures (below -15 degrees F).
2.
If the transmission has failed in cold ambient temperatures, install the bypass kit when repairing or replacing the transmission. Follow proper
cooler flushing and transmission repair/replacement procedures found in the appropriate Service Manual.
NOTE:
In hot ambient temperatures, this kit will decrease the cooling capacity of the transmission's cooling system. As a result, unless the above stated
conditions exist, it is not recommended that this kit be installed.
PARTS REQUIRED:
1
4874284
Universal By-Pass Assembly kit (See Figure 1 for kit contents)
REPAIR PROCEDURE:
This bulletin involves the installation of a cold weather by-pass kit to the transmission auxiliary cooler circuit.
1.
Disconnect the negative battery cable and isolate.
2.
Raise the vehicle for access to the transmission housing. The by-pass assembly will be connected to the existing transmission lines and mounted to
the transmission housing by means of a by-pass adapter.
3.
During this installation procedure, some transmission fluid will be lost when the transmission cooler lines are cut (allowing by-pass assembly
installation). Take proper precautions and check transmission fluid fill level upon completing the installation.
4.
If the cold weather by-pass kit has provision for an in-line temperature sensor, the threaded "thermal well" (in the pressure "P" line of the kit) must
be plugged with either the temperature sensor from the existing transmission line or the standard pipe plug provided. Consequently, if the vehicle
being serviced is equipped with a temperature sensor (i.e., heavy duty BR truck), remove the temperature sensor from the existing line by
unthreading and install it in the "pressure" line provided with the kit. Use Mopar Thread Sealant, P/N 4318044, to ensure a leak free seal.
5.
Disconnect the pressure and return lines from the transmission housing quick connect fittings.
6.
Remove and discard the quick connect fittings from the transmission housing.
