904 Trans ????

[old tired rebel]

1978 Chrysler Cordoba 318 with a 904 Transmission.

How do I tell if I have a lock up or non lock up transmission?

I forgot to put in that the trans is still in the car and nothing is original as far as I know.

 

[cudamark]

You mean you can't tell when it shifts into lockup? A good tach should show that. You can always look up the assembly number in the factory parts manual or a Hollander/Mitchell interchange manual. If the transmission is out of the car, pull out the converter and take a look at the input shaft. If the splines go all the way to the end, it's a non-lockup. If there is a 3/4" smooth machined surface at the end of the input shaft, it's a lockup. If it has never rebuilt, some convertors had a sticker that said "lockup" on it.
Thanks, Mark

 

[Shorty Thompson]

The way I've seen was 2 ways . 1 pre - electronic ; There was a boss casted into the housing near the rear of the tranny , near the tailshaft that was never opened or threaded . 2 electronic - there will be a switch that reseambles the neutral saftey switch in the same location.