I thought the folks on this forum should know this information.
There's been enough chronic overheating problems with the auto trans thermostat (in the 68233384AA Heater-Transmission), which controls the flow to the fluid cooler, that Jeep has superseded the original assembly with a new part number (68485460AB). Some have failed the transmissions from this issue.
The original assembly (68233384AA) is multifunctional, in that it has a valve body with the thermostat for the cooler as well as a heat exchanger which uses engine coolant to pre-heat the transmission fluid for initial start-up and cold weather operation. The issue with the original valve is the thermostatic valve has been found to be sticking and not allowing transmission fluid flow to the cooler.
The revised valve/heater assembly, 68485460AB, eliminates the thermostatic valve and allows full flow to the cooler all the time
, while retaining the heater as full flow as well. The message here is; if your trans is running excessively hot, get this part on there. I bought mine for $62 online to replace it preemptively.
Another issue with this part is that an aftermarket (JE Reel in one case) that uses larger universal joints caused an interference which resulted in the driveshaft cardon hitting the heat exchanger during off-roading.
I bought the new valve/heater assembly and decided to eliminate the heater function (since I live in the southwest) and replace it with a full flow plate where the heat exchanger mounts. I machined a plate from 6061 T6 with the hole pattern as well as a cross drilled passage to simulate the flow path of the heat exchanger. This plate is about half the thickness of the heat exchanger and will not have any interference with any driveshaft I may end up with for my lift.
There's been enough chronic overheating problems with the auto trans thermostat (in the 68233384AA Heater-Transmission), which controls the flow to the fluid cooler, that Jeep has superseded the original assembly with a new part number (68485460AB). Some have failed the transmissions from this issue.
The original assembly (68233384AA) is multifunctional, in that it has a valve body with the thermostat for the cooler as well as a heat exchanger which uses engine coolant to pre-heat the transmission fluid for initial start-up and cold weather operation. The issue with the original valve is the thermostatic valve has been found to be sticking and not allowing transmission fluid flow to the cooler.
The revised valve/heater assembly, 68485460AB, eliminates the thermostatic valve and allows full flow to the cooler all the time
, while retaining the heater as full flow as well. The message here is; if your trans is running excessively hot, get this part on there. I bought mine for $62 online to replace it preemptively.Another issue with this part is that an aftermarket (JE Reel in one case) that uses larger universal joints caused an interference which resulted in the driveshaft cardon hitting the heat exchanger during off-roading.
I bought the new valve/heater assembly and decided to eliminate the heater function (since I live in the southwest) and replace it with a full flow plate where the heat exchanger mounts. I machined a plate from 6061 T6 with the hole pattern as well as a cross drilled passage to simulate the flow path of the heat exchanger. This plate is about half the thickness of the heat exchanger and will not have any interference with any driveshaft I may end up with for my lift.
