What did the A518 come in?

70DartMike said

Just curious where you would find an A518 transmission?

Also, I have an overdrive transmission mated to a 318 from a mid 80's Chrysler 5th Ave, I am wondering if its a 904 with overdrive? Or if it is something else, how to determine what it is? I know the difference between a 904 and 727, but not up to date on my other transmissions.

I'm asking because the 904 in my 65 Valiant leaks where the cables enter it, and being its a daily driver with a 273 2 bbl, I'd like to get a bit better fuel mileage on the highway. I'm considering swapping in a transmission with overdrive.

Click to expand...

The 5th Avenue trans is more than likely a lockup 904, aka the A999

The 518 was used in Dakotas and Rams in the 1990s, make sure you get an RH and not an RE, I believe the way to identify a 518/500 from a 727/904 is the overdrive unit makes the transmission longer, somebody else can correct me if I'm wrong there. The 518 shares it's pan gasket with the 727 and the 500 does the same with the 904, I personally love the A500 behind the 360 in my Mopar Express Dakota, makes it purr down the highway with the 3.90's in the rear. Both the A500 and A518 have a 0.69:1 overdrive but the first two gears and reverse are different between the two.

The 518's gears are: 1 - 2.45:1, 2 - 1.45:1, 3 - 1.00:1, OD - 0.69:1, REV - 2.35:1

The 500's gears are: 1 - 2.74:1, 2 - 1.54:1, 3 - 1.00:1, OD - 0.69:1, REV - 2.21:1

Just make sure that you get an RH (as in 42RH or 46RH, 42 being the A500 and 46 being the 518) as the RE uses electronic governors (if i recall correctly the TCMs for the RE's learned how the driver drove the car as to adjust the kickdown and shift points, but that may be it's successor)