Speedo Correction on a Bronco II.

[engdept]

Whenever the truck is stopped, it is on 0 mph; I am 100% positive of that.

Like I said, I will check it again whenever I get off today.

 

[Earl43P]

You will discover that at rest, the needle has to have tension against the peg.

Use forceps to rotate the shaft to compensate out the erroneous 10 mph, then place the needle back on, so that tension occurs. It will probably take several tries to get it spot-on.

 

[engdept]

Alright, I checked the needle at rest and it is right on 0 mph. Below is the speed numbers I got using my GPS. The first number is what the speedo is reading and the second is what the GPS was indicating.

Speedo = GPS
20 = 16
30 = 24
55 = 45
65 = 53
75 = 61


Anyone got any advice for which gear to use? I have a red speedo cable gear with a red t-case output shaft gear in it now.


EDIT: I just counted the teeth on the speedo gear and it only has 16 teeth. I was going by the Tech Library's info that the red speedo gears have 21 teeth. I will go order a 21 tooth gear tomorrow at the local Ford dealership and see if that works.

 

[rickcdewitt]

i say use the 20 or 19 tooth,it comes out closer.i get a little over 19.5 for you

you bought the wine colored gear it looks like.

 

[engdept]

I am going to get the 19, 20, and 21 tooth gears; at just a few cents over $5, I don't see why not. That will give me the chance to experienent with it.

I will let you know which one I use.

 

[engdept]

I installed a 19 tooth speedo cable gear in it and it is 2 mph off across the board. I am sure that is closer than it ever was stock.

I guess that my stock gear wasn't the 19 tooth. The tech library has some mistakes in the color codes on the cable gears.

For a 2.9 v6 with 4.56 gears and 31's, it takes a red worm gear and a 19 tooth speedo cable gear.