Vauxhall Crossland automatic gearbox oil contamination

This vehicle was presented with a customer concern of coolant loss and a transmission oil leak.

On initial investigation there were signs of oil contamination in the engine coolant reservoir which, by the odour seemed like automatic transmission fluid. Also automatic transmission fluid gathering on the underside of the gearbox.

Further investigation revealed that the transmission oil leak was emitting from the gearbox breather. The leaking fluid showed signs of contamination (Milky emulsified oil).

The next step was to drain the transmission oil. This confirmed excessive quantity of emulsified oil within the gearbox.

Going by the evidence, the transmission oil cooler was removed for inspection.

A pressure check was carried out which conformed the cooler was leaking internally and allowing engine coolant to enter the automatic transmission.

The cooler was replaced, cooling system flushed and the transmission oil was changed multiple times to flush out the contaminated oil.

Extensive road testing was carried out to confirm the gearbox operation