Speedo Gear.. What do I need...

[MattStarr]

I got 31 BFG AT's put on today with my TT/Shackles. My speedo is now off I assume. I went to Ford to get the little gear I need to put in the rear diffy to fix it. But I dont know what size I have and what size I need to get. He told me to find out exactly what I need and to come back with the color and tooth # of what I need because that have to special order it. I have 3.73LS and V6 SOHC. Thanks guys.

Or does anyone know of anywhere online I could get the gear for cheaper?

 

[jared ajlouny]

the gear is only ten bucks.there is a thread about it on here some where, i forget where tho.

 

[wa4kc]

Its more expensive, but the power programer from Apten will change that setting. The programer will test for codes and change settings for better performance also. I dont have one myself but that is what I read.

 

[jared ajlouny]

i got mine from the ford dealership for only 9.50, hows that more expensive?

 

[Maniak]

Is the '97 one of those that gets the speed from the ring gear? or is it still getting it from the VSS on the end of teh speedo cable by teh tranny/xfercase?

If its the "gear" kind you have to take out your stock on and count the teeth (and get teh color of the plastic). Then figure out how much you want to change your current speed reading and get a gear that much bigger/smaller (depending on which way you need to adjust.

~Mark

 

[MattStarr]

Can anyone answer my question???? I searched and couldnt find the thread.

 

[Arnie897]

This was over in the "List of Useful Threads"....it's what I used on my 97 sport and was very accurate.

New Teeth = (Current Teeth x Speedo Reading)/Actual Speed.

Manual Transmissions and all 4x4s:

16 tooth wine(C0DZ-A)
17 tooth white(C3DZ-C)
18 tooth yellow(C0DD-B)
19 tooth pink(C0DZ-B)
20 tooth black(C1DZ-A)
21 tooth red(C4OZ-A)

2WD Automatic Transmissions:

16 tooth blue(D0AZ-A)
17 tooth green(C7SZ-A)
18 tooth gray(C7SZ-B)
19 tooth tan(C7VY-A)
20 tooth orange(C8SZ-B)
21 tooth purple(D0OZ-B)

 

[MattStarr]

Arnie, thanks alot, I forgot to look in the list of useful threads..........

Ok, I see that, but how do I know which one I have which one I will need? And if I need to remove it to tell, could you please tell me how.. Thanks.

 

[Arnie897]

You just have to crawl under there and look. It's a thick cord going toward the top of the transfer case. I don't remember exactly how I did it....but the gear is on that cord...you pretty much just pull it out. There might be one bolt holding the cord in place and a clip holding the gear on the cord. Mine was pink and I swiched to the white one when I put on my 285's. Mine came stock with the 235's and 3.73's. Hope this helps.

 

[Arnie897]

I also used this webpage to help me do some calculations.

http://home.comcast.net/~cboug/Tire_Gear_Calculator.htm

 

[MattStarr]

So basically since I got bigger tires, I need a gear with 1 more tooth?? Does this seem right?

 

[Arnie897]

Since I went from the pink to the while tooth gear I'm thikning that you need one with less teeth....maybe the yellow....that's just a guess though. Let the numbers speak for themselves...

 

[MattStarr]

How do I know how many current teeth I have? Is it on the door sticker?

 

[Arnie897]

You have to go under there and count em

 

[Robert]

Your V.S.S. is on your transfer case (or transmission tailshaft if 2WD), not your rear differential. Ford didn't begin using the RABS (which is on your rear differential) until '98. This is what you are looking for (the V.S.S. is the white object in the picture):

 

[MattStarr]

Robert... Do you just unscrew that to get it out?

 

[Mascman]

You guys are lucky! I have a '98 and had to buy the Jet computer to recalibrate my speedo...I still haven't hooked it up. That gear is a whole lot cheaper too.

Another solution, the one I'm using now, is to become very good at speed math. When I see a cop, I look at the speedo, calculate how fast I'm going in relation to what my speedo says I'm doing and then hit the brakes!

Last step is to pray and watch in the rear view mirror for lights and hope your calculation was correct!

But seriously, you need to calculate the ratio you have with the stock speedo gear and tires, and then figure out a new combo that will equal the same ratio. Use the link above that has the calculators to help out.

After a quick calculation it looks to me like you will use 1 or 2 less teeth, but you'll need to figure out for sure.