Speedo drive gear tooth count?

[MediumD]

Would a 1994 4R70W have a 7 or an 8 tooth speedometer drive gear? Thanks in advance.

 

[JMiles_T]

7

 

[MediumD]

Cool.

Another question - does anyone make a 22 tooth speedo gear?? With my tires that would be perfect. I've only found 21 or 23.

 

[JMiles_T]

I took a few minutes to look around and I couldn't find one.

If you don't find one, you could always get a Speed-cal.

Either that or buy one of those other 2 gears, and remember to add/subtract a few numbers from what your speedometer actually says.

 

[Moes8]

I took a few minutes to look around and I couldn't find one.

If you don't find one, you could always get a Speed-cal.

Either that or buy one of those other 2 gears, and remember to add/subtract a few numbers from what your speedometer actually says.

i thought speedcal was for obd2
or doesnt it matter?

 

[MediumD]

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=330007906566

So one of these?

It says 94-98 auto Mustangs, which would include OBDI/EEC-IV, and have the 4R70w like my 94 Mark VIII.

How much fine tuning can you do with one of these? Do they have a potentometer or something like DIP switches? As you might be able to tell I'm new to the world of cars where everything is electronic, and new to Ford for that matter...

If I were to use a 21 tooth, the speedo would read 94.325% of actual, so 70.74 would appear when I'm doing 75 (or 103.308%/77.48mph @ 75.) If this speed cal could get it closer than that I would invest in one.

Thanks a lot for your help School_Zone.