Originally Posted by Fang16
I've got a th400 with a tag on the right side that reads LM 9213A and below that is 90-LMA-1152. What do these decode as? I've looked for a VIN on the case but can't find one. One of the reasons I need to know is in hooking up an electronic speedo to it. It has the two wires from the ele speedo coming out of the tail shaft and of course the 1 prong kickdown switch farther up the case on the drivers side.
All this will tell you is that it is a 1990 vintage TH400 unless you can find someone that has seen a vehicle that this code was in. I have never seen a code list for TH400s in the 30 years I have sold transmission parts. I am sure that somewhere in GMs archives there is something showing code listings, but I doubt if it was ever released for general use.
I see no reason why you need this information to hook up an electric speedo. Speedometer calibrations are always outside of the transmission and only vary because of rear end ratio, tire size, and driveshaft speed (usually the same as transmission output shaft speed). Output shaft speed is sensed either through magnetic pickup using a reluctor or through manual pickup using speedometer gears.
Most TH400s had VINs on them. Later TH400 VINs are hard to find since most were laser engraved in varying locations. Early VINs were always stamped on a pad just above the pan rail on the driver's side.