Android1

I have a 1998 GT car with a 04 GT engine and tranny installed

The car in 1998 was an automatic and now it has a standard transmission. The speedometer shows irrational speeds when only doing about 10mph. So I guess it is connected because the miles keep increasing (at a very fast rate BTW)

How can I fix this? Do I have to replace the original AUTOMATIC Speedo and cable for one out of a STANDARD 1998 or am I SOL because I have a 2004 motor installed?

Thanks

uberstang1

The engine has nothing to do with the speedo on a 98, its controlled by a plastic speedo gear in the transmission, I'm assuming the rear end has gears installed or your trans already had a speedo gear that doesn't match your existing rear gear ratio. You either need to get a replacement speedo gear to match the rear gear ration and if thats not available you'll need the speedcal box.

Android1

The engine doesn't but the TRANNY does. The original tranny was an AUTOMATIC and now it has a 5 Speed tranny. Would that be the issue? I think yes. Should I try to find a Speedo from a 5 Speed 1998 and the issue could be resolved? or should I try to calibrate the ratios?

uberstang1

Changing the speedometer will NOT solve the problem. What gears are you running in the rear end? Refer to my original post, there is a chance the speedometer gear in the MANUAL trans was changed by the previous owner to correty his speedo if their were gears installed in the car.

'''Daddy's_Toy'''

If the transmission is also a 2004 I believe they have a different speed sensor in them (electronically driven) vs the mechanical one in a 98. I do believe everyting still hooks up but they read crazy fast, and I'm not sure what an appriopiate fix is but I'll ask some of my buddies and try to get an answer.

Android1

This is exactly the issue. It reads crazy fast but everything hooked up well. I do have a 04 wiring assy for the tranny which will enable me to connect the reverse lights too. I am not sure if that will get the speedometer to read more accurately.

'''Daddy's_Toy'''

Might Want to give Dallas Mustang a call and see if this will fix ur problem

http://www.dallasmustang.com/mustang...DED-RANGE/7626

Or if they have an application for your trans

'''Daddy's_Toy'''

Sorry I forgot to get back to ya earlier...