Hi guys. I have a problem with wrong reading speedometer. You told me some time ago that I need to change my speedogear. I had a look on it and I have 17 teeth speedogear (green). I have swapped transmission from some Mustang (my father did it), so that must be the reason. I don't know what rear-end ratio that stang had. So please tell me, how many teeth speedogear I need. Here is a small help:
I'm driving 90 km/h (56,25 MPH) and the speedometer shows 70 MPH.
I think I need 19 or 20 teeth speedogear, but I'm not sure.
PS: I have stock rear axle and a bit smaller tires (215/60R15 I think).
Each tooth added to the gear will reduce it 3-4 MPH, I'd go with the 20...
It will reduce the reading 3-4 MPH in which speed? 30 MPH, 50 MPH, 100MPH,...?
Is this new transmission a 5 speed or an automatic?
What was the original?
Also, what is your axle ratio?
60mph...
http://www.steeda.com/products/speedometer_recalibration_gears.php
If you can figure out your axle ratio, you'll be able to buy the correct gear.
It's C3 automatic. Original was C3 too. Rear end ratio is 3,45, as all TCs have.
So, please tell me, what
YOU have. I know all the links with speedogears and calculators, but I don't know one number (how many teeth have the drive shaft gear), so I can't get the result.
Unless you find someone with same combo that you have, their gear info will be useless to you... The '87-'88 automatics used a A4LD tranny and 3.73 rear gears... With a Super Coupe AOD, 225/60/16", and 3.73s I run a 21 tooth gear to be correct... The Std Fox Bird AOD & 3.73 requires 23 tooth gear(which Ford doesn't make), aftermarket suppliers sell a Chrysler gear for this application...
What's wrong with my 86? I thought that all these 4 eyed turbo coupes had C3 and 3,45 LSD. Don't worry about tires, it's only minimal difference.
Here is a speedo gear calculator that I use and it works very well.
http://www.angelfire.com/mb/mustangsrule/speedogear.html
Typically you can use a flash light and look up into where the speedo cable goes into the tranny and determine the color of the drive gear (gear on the output shaft of the tranny). Once you have this, the circumference of the rear tire (typically you can find this on your tire from http://www.tirerack.com), and the rear gear ratio you can find the closest driven gear to get the speedo correct.
Darren
While I'm not sure of the C3 trannys, most automatics have the teeth cut into the output shaft, thus it has no color, I doubt color listed for the T-5 would be correct anyway...
Nothing unique about your combo, just that I don't know of any others that have a 86 TC with automatic...
I think it can be 85 or 86. I'll take a look around. In short past there have been here few new registered 85/86 TCs.
Well, my donor car was a 86 XR7 with a C3 and 3.45s. What information do you need?
How many teeth does your speedogear have.
I've send you a message with link to this thread, but you were faster :-D
Was not aware the teeth were cut into the output shaft on the C3. Learn something new everyday!
Darren