speedo ratio
Thread Starter
|
Postmaster
Joined: Nov 2001
Posts: 3,351
Likes: 1
From: Escondido, CA
speedo ratio
I know Ford uses different color drive gear for the speedometer. Does the stock Ford guage have a 1:1 ratio though? I am building a new dash face with a setup for the iEquus 8000 series in mind. Reading the tech sheet their speedometer is a 1:1 ratio and I think Ford is the same but I want to know for sure. I have already made the aluminum insert for screwing on the frame of the stock dash face. All I need to do now is cut the holes for all the guages. I am holding off until I know for sure I will be able to use these. I even went as far as to buy a set of LED indicator lights, european terminal board for hooking up a power board for all the guages, and a set of 12 pin male and female connectors from radioshack. This way I have everything on one common disconnect minus the water temp, oil press, and speedo inputs.
Fleet Owner
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
Mark, The short answer is yes 1 to 1.
You can easily get the rear ratios confused, where things start from. It is my understanding that 1 to 1 means one revolution out is caused by one revolution in. The engine is turning 1000 rpms, the tranny is getting 1000 rpms in, multiplys the lower gears and turns 1000 rpms out in hi-gear. The rear gear has different ratios, high numbers for pulling and low numbers for cruising that changes the above numbers.
Speedo gears were color coded, and each one had a different tooth count. IMHO The tooth count is what you want to use because I have the same count gears in different colors.
Basically if your speedo gear is the proper one for your rear ratio you will have 1 to 1 at the end of the speedo cable where it attaches to the speedometer.
hope I didn't cornfuze the issue
Pete or John can probably splain it better.
John
You can easily get the rear ratios confused, where things start from. It is my understanding that 1 to 1 means one revolution out is caused by one revolution in. The engine is turning 1000 rpms, the tranny is getting 1000 rpms in, multiplys the lower gears and turns 1000 rpms out in hi-gear. The rear gear has different ratios, high numbers for pulling and low numbers for cruising that changes the above numbers.
Speedo gears were color coded, and each one had a different tooth count. IMHO The tooth count is what you want to use because I have the same count gears in different colors.
Basically if your speedo gear is the proper one for your rear ratio you will have 1 to 1 at the end of the speedo cable where it attaches to the speedometer.
hope I didn't cornfuze the issue
Pete or John can probably splain it better.
John
Thread Starter
|
Postmaster
Joined: Nov 2001
Posts: 3,351
Likes: 1
From: Escondido, CA
Thanks for the reply John. I understood the the long explination from all the work I have done before. My main problem was that "oh crap" feeling when I didn't know what the ratio was for the 90 degree drive angle change going from the input on the back of the speedometer to the nylon splined shaft. Looking at it I could guess and adapt using the driven gear on the other end of the cable on the transmission.
The plastic color driven gears have a different pitch like a screws. The steeper the pitch the less turns it takes to drive them in. Hence why 4.11 rear ratio driven speedo gears have a shorter life span then a 3.00 driven gear. They both have to have the same teeth count though.
The plastic color driven gears have a different pitch like a screws. The steeper the pitch the less turns it takes to drive them in. Hence why 4.11 rear ratio driven speedo gears have a shorter life span then a 3.00 driven gear. They both have to have the same teeth count though.
Thread Starter
|
Postmaster
Joined: Nov 2001
Posts: 3,351
Likes: 1
From: Escondido, CA
It applies to all the plastic speedo gears as far as I know. The only true difference that I know of is on the output of the c-6 tail shaft that can have 6 or 7 drive teeth depending on the year and type of transmission. I can check for sure since I happen to have several different color driven cable gears on my workbench shelves.
Fleet Owner
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
I have several different tooth count gears in my collection. I know they run from 16T to 22T. I changed tooth count when I changed my rear from 2.75 to 3.00. I believe I went from a 16T to a 17T count.
The auto gears have a right hand pitch while the st. dr. have left hand.
let me know what you find.
John
The auto gears have a right hand pitch while the st. dr. have left hand.
let me know what you find.
John
