Transmission Cooling: Notes

The transmission fluid cooling system without an auxiliary transmission fluid cooler consists of the following:

• An in-tank transmission fluid cooler inlet tube
• A non-repairable in-tank transmission fluid cooler
• An in-tank transmission fluid cooler outlet tube

The transmission fluid cooling system with an auxiliary transmission fluid cooler consists of the following:

• An in-tank transmission fluid cooler inlet tube
• A non-repairable in-tank transmission fluid cooler
• An auxiliary transmission fluid cooler inlet tube
• An auxiliary transmission fluid cooler
• An auxiliary transmission fluid cooler outlet tube

Located inside the transmission case is a thermal bypass valve. The thermal bypass is used to route fluid to the cooler when operating temperatures increase, or to return fluid directly to the transmission lube circuit. When the transmission fluid temperature is below 185°F (85°C) no fluid is routed to the cooler. It is essential that the transmission fluid level be checked and adjusted only when the fluid temperature is verified with a scan tool.

The transmission fluid flows from the transmission bottom fitting, to the in-tank transmission fluid cooler, to the auxiliary transmission fluid cooler, if so equipped, and returns to the transmission top fitting.

For the transmission fluid cooler backflushing and cleaning procedure, refer to AUTOMATIC TRANSAXLE/TRANSMISSION - 6R80 .