Transmission input speed sensor- how to change
 

2008 Saturn Astra input speed sensor - DIY replacement steps. Auto transmission.

Symptoms: leaking around sensor. Odd shifting patterns, especially downhill. No codes shown.

Even though I don't have an Astra, I'm curious to know it that fixed the problem. I'm sure others would like to know too.

The Japanese Aisian AF-17 (AW60-42LE)) was a very reliable, highly-rated 4-speed automatic transmission.

The major "transmission" flaw was the Saturn's defective radiator, which tended to combine engine coolant and transmission oil.

Owners should speak to a transmission expert about adding a separate transmission oil cooler. It is inexpensive insurance to prevent this failure. Our cooler fit between the radiator and AC condenser, so GM engineers likely considered this during design.

Saturn issued a partial recall. Our radiator was inspected by the dealer but it failed a few years later. That destroyed the transmission. Plus the coolant became the consistency of a chocolate milkshake; it was difficult to clean and required replacing the swollen rubber coolant hoses (and seemed to destroy some o-rings (e.g. coolant tank cap, oil cooler seals, thermostat, maybe the oil pump gasket...)

Here is a nice article about the AF-17 from Gears Magazine and a schematic
https://gearsmagazine.com/resources/...0_DEC_alla.pdf
https://at-manuals.com/manuals/aw-60-40le-42le-41sn/