Recalibrating the speedo - Off-Road Forums & Discussion Groups
Ford 67-96 F-Series, 78-96 Bronco All discussions of 67-96 F-Series Trucks and 78-96 Broncos

 
LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 11-15-2001, 07:20 PM Thread Starter
 
Join Date: Oct 2001
Posts: 2,508
Thanks: 0
Thanked 0 Times in 0 Posts
 
Recalibrating the speedo

Anyone done the recalibration on their Bronco after getting larger tires? I found a tech article explaining how it is done, but I am just not following where the wire or connection is that needs to be ground before you turn on the ignition and play with the reset dials. I'm also not quite following the math in the article for the re-computation. This of course is the procedure for the newer electronic readouts. I don't want the dealer doing it for $120 if I can handle myself.

The Juice, '95 Ford Bronco XLT, White, 5.8, E4OD, 4" Rancho, 35's, 4.10, ARB/LSD, lots else
TheJuice is offline  
Sponsored Links
Advertisement
 
post #2 of (permalink) Old 11-17-2001, 12:24 AM
**DONOTDELETE**
Guest
 
Posts: n/a
Re: Recalibrating the speedo

All I can remember is the wire to ground is by itself between the ashtray and glovebox.But be careful because the e-prom chip or whatever it's called can only be reprogrammed 5 times then will need to be replaced.

1996 F350 SRW 4X4 POWERSTROKE 4"LIFT 4:10 38"GROUND HOGS FULLY CUSTOMIZED
1979 BRONCO 460 C-6 205 3:50'S 33"THORNBIRDS
PROJECT CJ7 ON HOLD
post #3 of (permalink) Old 11-18-2001, 12:14 PM
Mud in my Veins
 
Steve83's Avatar
 
Join Date: Dec 2000
Location: Memphis, TN
Posts: 5,301
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: Recalibrating the speedo

Where'd you find this article? There was a thread about it a while back in which I posted the Ford procedure I got from another source. Have you read it?


[email protected]
Steve83 is offline  
Sponsored Links
Advertisement
 
post #4 of (permalink) Old 11-18-2001, 09:33 PM
Mud in my Veins
 
muddybronco's Avatar
 
Join Date: Oct 1999
Location: woooooo pig sooooooie!
Posts: 6,842
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: Recalibrating the speedo

Swamp Donkey (from the ford-diesel.com forum) has a page on it, and his math is as follows:

***
Tire Circumference = Tire Diameter x 3.1416 (Note that this does not take into account the squat of the tire when loaded. To allow for that, I used a tire diameter of 41", although the actual height was 41.5")

Revolutions per Mile = 63,360 / Tire Circumference in Inches

Conversion Constant = Tire Rev per Mile x Teeth on Sensor Gear / 8,000

(The number 63,360 is inches per mile; 8,000 is a the number of pulses per mile the PSOM needs to be accurate.)
***

The number of teeth on the sensor gear in an 8.8" is 108. Instead of figuring your revs/mi, you might try looking them up on the tire MFG's page... it's more accurate (unless you know your exact tire diameter).

If you want to see his page, it is HERE.

He has some really cool custom fabrication stuff on his page.

As far as the wire, it was just a grey plug with a single wire hanging under my glovebox somewhere, and said PSOM on the side of it in white letters. Just take a wire and stick it in there, and then stick the other end of a good ground... just get a long wire and hook it into the battery ground clamp.

You probably can find the button pushing procedure, if not just ask.



Your Toy is loaded huh? Does it have Power Engine?

<A HREF="http://www.arkansasmud.com/" target="_new">
ArkansasMud.com</A>
muddybronco is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Off-Road Forums & Discussion Groups forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome