Speedometer correction devices -opinions?

[legoms013]

I'm looking into buying a Superlift Tru-Speed or a Jet Accu-Speed speedometer correction module. Or another brand if someone has some suggestions.

Anybody have any experience with either one? Opinions?

I have 4.88's and 33's, and will run 35's someday. My speedo reads between 80 and 85 when actually only going 65mpg....I'd like to make it accurate again lol.

If I am not mistaken, my 1996 Mazda's speedo is determined electronically, and not with a gear in the transfercase or transmission. Correct me if I am wrong ( since I'd rather speed less money as opposed to more, these damn modules are expensive!).

The Tru-Speed runs about $200+....and the Accu-Speed about $135+.

THANKS

 

[4x4junkie]

I do believe '96 still has the speedo gear in the t-case. You should be able to just change that with one having a different # of teeth to correct the speedo (pretty sure '98+ is when they went fully electronic off the axle sensor).

 

[legoms013]

I do believe '96 still has the speedo gear in the t-case. You should be able to just change that with one having a different # of teeth to correct the speedo (pretty sure '98+ is when they went fully electronic off the axle sensor).

I finally had some time to peak underneath and yes its a gear driven sensor. Found out that it is using a yellow, 18 tooth drive gear. Which is listed for manual trannys only on this chart:

http://www.therangerstation.com/tech_library/Speedogear.html

I have a auto though??? Lol

I determined with some math that I need the 21 tooth gear. But for an auto or manny tranny now is the million dollar question? Maybe I will buy one of both and return the one that doesn't work!

 

[4x4junkie]

Tranny doesn't matter (remember your gear is in your t-case, which all t-cases are the same

).

You need a "manual tranny" gear (a 2WD automatic would use the "auto" gear).

 

[Captain Ledd]

I thought the DRIVEN gears were all the same (the one you pull out on the sensor or cable), it was the DRIVE gear (the one on the output shaft) that is different between the auto/manual? The only difference in those being how it mounts on the shaft.

 

[4x4junkie]

No, if you look at the tech page, there are separate gear listings for manual & automatic trannys (the gear that goes onto the end of your speedo cable). I'm not sure the exact difference between them though (never dealt with one on a 2WD auto yet).

 

[legoms013]

I thought the DRIVEN gears were all the same (the one you pull out on the sensor or cable), it was the DRIVE gear (the one on the output shaft) that is different between the auto/manual? The only difference in those being how it mounts on the shaft.

Couldn't tell yah

Anyway, the guy at my Ford dealership sold me a RED 21T P/N C4OZ-A (C4OZ-17271-A)

Off of the "manual" chart there on this page:

http://www.therangerstation.com/tech_library/Speedogear.html

And the speedo is pretty dang close. Not exact, but it will work