Hi i have 1st generation 12 valve cummins engine runs great but the tranny is bad i can not identify it. i know it is 3 speed auto but don't know which one it is i have talked to local dealer and parts houses no 1 seems to have a clue. can anybody help?

 

A518???

 

thank you

 

What year? If it has overdrive its an A518, if not its a 727.

 

Keep in mind that the diesel versions are different from the gas versions when getting parts.

 

His card in the corner says it's a '90. That would make it a 727 unless someone changed it out.

 

X2 on the 727 is a 37RH if it's a 3 speed factory trans
Components uniquie to the diesel are Planetary Gears, Clutch packs, Governor Weight Assembly.

A518 is a 46RH 4 speed rear wheel Hydraulic.
Components uniquie to the diesel are also Planetary Gears, Clutch Packs, Governor Weight Assembly, Diesel Thermo Switch, And does not have lock-up.