my cable seems to be intact all the way thru i have turned both sides and it works,so why wont my speed gauge work???automatic...

 

Bad drive gear in the back of the transmission... Defective cluster...

 

To elaborate on swarts post.
in the tranny tailhousing is the speeodo gears, tehy are made of plastic. One of both could be worn out.

Being that you have an '85 your speed cable runs to teh back of your cluster where it is converted to a signal that the gage understands. The (for lack of the proper term) could be broken.

The easiest fix the gear on the cable end. If it is the gear on the output shaft the t-case has to come off. If it is broken behind the dash, the instrument cluster has to come out.

 

thanks hanr would it matter that i can spin the gauge and it moves very freely or would it have a little pressure on it if the cable is disconnected??? how would i be able to determen which would it be??without haveing to rip the tranny apart or part of it i have no experience with any tranny

 

The easiest thing to do is take the cable out of the tranny, shine a flashlight inside and look at the gears. It'll be pretty obvious if they are chewed up.

Another possibility is that your cable needs lubrication. I didn't mention it earlier because you said the gage didn't work. If it was erratic or off when cold then your cable needs lubrication. The best way to lubricate is via the top of the cable behind the instrument cluster. Pop it out of the tranny and go from there.

 

Pull the cable loose at the tranny and hook a drill to it and see if your speedo works. If it does it is indeed your drive and/or driven gear in the tranny. On my 4x4 I have to run the drill in reverse to make the speedo turn, don't know if its different for a 2wd.

 

thanks neo im gonna try it sat hopefully if i can get more input on other things im wondering about btw what other mods have you done and how much has it helped??

 

Headers, open element filter, fiero valve covers so far on the motor. Saving most my tricks for a 3.4 swap.

For the rest of the truck way too many mods to list

 

kool neo, other than looks what is the reason for the diff vavle covers?

 

They use a thick rubber gasket instead of the cheap cork ones and with the way a 60 degree block is designed, they don't leak like the factory ones. Looks was only a nice plus for the reason I got them.