Speedometer drive questions

seaboltman · 06:27 PM

Ok heres the situation

1987 Manual Car parts car

1986 Automatic car

If anyone has been paying attention, or taken a casual interest they know im doing an automatic -> manual swap.

I was Familiarizing my self with the process of the transmission removals and installations and i noticed something. In the removal/installation process in the manual i have says for the manual car, i need to "pull off plug on speedometer drive" Now this is obviously how the car determines how fast its going.

The problems is, on the instructions for the automatic car, it doesnt say anything about this cable. I know that on the pre-85.5 they took the speed from the wheels or there abouts, but is this the case for the automatic cars of all ages?

I guess that brings about another question. If the speed is infact taken from the wheels then, what do i do? Will there be any problems if i continue to run the wheel speed sensor, and dont connect the sensor on the trans?

Thanks for the info

seaboltman · 12-12-2004, 06:41 PM

someone must know the answer! meh ill check back after some studying

seaboltman · 12-12-2004, 07:29 PM

Guess ill have to wait until tommorow for an answer. Oh well

ernestedward · 12-13-2004, 04:42 AM

I can't answer all your questions, but maybe one or two. I have no idea if speed was taken from the wheels on autos of all years. Never heard of this, but never heard that it's not true, either. Remember that the sensor in the transmission is picking up a magnetic pulse - the sensor on the wheel is manual (actually a spinning cable that drives the speedo). The sensors and speedometers are not compatible across types. Also, on post 85.5 cars there's not even a place to insert the manual pickup in the spindle. This leads me to believe that it's pretty unlikely an auto would use the manual (wheel) sender. Sounds like your best bet is to use the gauge cluster from the Manual donor and swap it into the automatic reciever. That way you can run the sensor to the manual transmission no problem.

seaboltman · 12-13-2004, 05:27 AM

Hum, well i was planning on swapping out the gauge cluster (provided i can roll back the odo so it will read right (anyone know how???)) , ill have to take a peek under the car and see if maybe they just left it out in the directions.

ernestedward · 12-13-2004, 08:24 AM

What makes me think that it DOES come off the auto transmission is that I've never found a post 85.5 spindle with a hole in it (would have been very useful..). Most likely it either comes from somewhere else or it's on the transmission.

seaboltman · 12-13-2004, 10:24 AM

Ok

carsontc · 12-13-2004, 04:58 PM

85.5 and newer 944 cars have electronic speedometers and have the speedo sensor in the transaxle. pre 85.5 have a mechnical speedometer cable driven from front left wheel