So yesterday I put my car up on some car ramps to change my oil. Well while in the process of this something happened cause when I got out there was quite a bit of smoke coming out of the transmission. Now, it has recently been replace and it is going right back.

Anyways, I then drove it to wash it (not noticing anything at the time cause it wasn't far). I washed it and even sprayed under the car as best I could. I get back and park it and do my usual cleaning duties.

Later that night I go to drive and notice my speedometer doesn't hardly work. It will work until about 25-30 and then it just drops down to 0. So, I got 2 theories.

1) During this smoke session of my tranny did it get some gears stripped off of it somehow to create this problem?

2) Or, did I get some water on/in the speed sensor area that could cause this?

Its a 1996 5 speed M/T 420a