What year? How many miles?

No, the transmission cooling lines did not fail. The radiator has two sections:

- One for engine coolant
- One for transmission fluid

There was an internal radiator seal failure between the two section. Oil and coolant mixed in your transmission and cooling system.

Sort of doubt yet may be the factory installed radiator. A terrible design and a separate transmission fluid cooler would prevent it. Or, using proper antifreeze and using distilled water. Or real demieralized & deionized water is better.

If you have an old radiator with side plastic tanks, replace it with an all-metal radiator. Used is fine if a trusted radiator shop can test the radiator for you for cheap.

Anyhoo, in the FAQ, read here:

- https://www.brickboard.com/FAQ/700-900/TransmissionAuto.htm
- https://www.brickboard.com/FAQ/700-900/Cooling.htm

The coolant is caustic and can sort of rapidly ruin the wet clutch disks in AW7x with a brown sludge coolant / Dexron ATF misture. Some may suggest you drop transmission sump pan (with replacement gasket on hand - or not) and inspect the pan for excess grit from delaminated / deteriorated clutch disks.

Questions?

Hope that helps.
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