Grand Cherokee 4WD L6-242 4.0L VIN S MFI (1993)
Transmission Cooler: All Technical Service Bulletins
A/T Cooler Hose - Blockage Inspection
NO.:
21-06-93
GROUP:
Transmission
DATE:
Mar. 26, 1993
SUBJECT:
Transmission Cooler Service
MODELS:
1993
(AN) Dakota/Dakota Sport
(AB) Ram Van/Wagon
(AD) Ram Pickup/Ramcharger/Ram Cab Chassis
(ZJ) Grand Cherokee/Grand Wagoneer
(XJ) Cherokee
(YJ) Wrangler
DISCUSSION:
When servicing an automatic transmission for any failure, it is extremely important to always check the transmission cooler circuit for blockage. Visually
inspect the cooler lines for proper routing and any signs of damage. Also, perform the flushing procedure and cooler flow test outlined in the service
manual. The flush procedure performs two functions:
1.
It assures that any contamination that may have accumulated in the cooler is not pumped into the transmission upon start up.
2.
It may eliminate a blockage in the cooler.
The cooler flow test should be performed at both cooler lines to assure that there is no blockage internal to the transmission, or in the external cooler or
lines. If flushing does not eliminate external blockage, the cooler (if available separately) or the radiator will have to be replaced.
Failure to identify a blocked cooler circuit can lead to a repeat failure. Fluid from the cooler travels back to the transmission and lubricates the gear train
and internal rotating components. If the cooler is restricted, there may be little or no lubrication pressure in the transmission, which will lead to
transmission failures.
POLICY: Information Only
