speedo drive gear?

[no mufflers]

I want to make sure I have the right driven gear. from what I can tell the drive gear in the trans is a 8 tooth but its hard to tell.

I am just wondering if there is a specific gear that was run, 7 or 8 tooth.

some specs: E4OD, 4.10, 33'' tires. as of now I have a 20 tooth driven gear.

 

[crash-harris]

You just need to make sure you have an auto tranny driven gear, unless you have a t-case. They use manual tranny driven gears. Google Ford speedo calculator if your speedo is off. You only need to know the drive gear teeth #, rear axle ratio and tire size.

 

[laserjock]

http://www.fullsizebronco.com/forum/23-technical-write-ups/109671-speedo-gears.html

 

[Shadetreemechanic]

The speedo gears are dirt cheap. I just bought several and experimented until my speedo matched my gps. If memory serves me there are 4 or 5 gear options from 14 or so to 21 teeth. The others are in the toolbox for future projects.
If your speedo is running low get one with fewer teeth, if too high then get one with more teeth.

 

[no mufflers]

thanks guys. from what I have observed with the bigger tires I am going about 5 mph faster then the speedo is saying. I have tried the gear calculator and it says im on.

I just wasn't sure if there is a standard drive gear teeth count, its hard to see in there.

 

[laserjock]

I think they are color coded on both sides. Are you 4x or 2x? I believe all the ford gears are color coded. The drive gear in my tcase is yellow.

I believe all the manuals and tcases used the same gears. Not sure about autos.


http://i133.photobucket.com/albums/q64/matts89stang/speedometer_gears.jpg

You must be registered for see images attach

You must be registered for see images attach

 

[no mufflers]

2x4. that's the weird thing, the gear in the trans looks like its steel. from what I have seen online it should be plastic and the way the teeth are cut it is hard to get an accurate count.

I had a 20 tooth in it and I found a 17 tooth in another truck so I will try it and see what I get. if that one is to far off I am left with a 18 or 19 to try.

 

[laserjock]

One of those references said it was machined in on the autos.

 

[icanfixall]

Color of the gear tells you what tooth count you have.

 

[no mufflers]

One of those references said it was machined in on the autos.

I think that must be my case. it looks like its steel. did they make a 7 and 8 machined gear?