Help please. My speedometer works but my - Vintage Mustang Forums
 2Likes
  • 1 Post By Woodchuck
  • 1 Post By 66coupe289
 
Thread Tools
post #1 of 12 (permalink) Old 06-26-2019, 08:02 PM Thread Starter
Senior Member
 
Join Date: Jun 2018
Posts: 237
Help please. My speedometer works but my

odometer doesn’t. 67 4-speed manual transmission. The speedometer is about 9 mph slow compared to the actual speed so I am guessing I need a different gear. Does this speedometer work the same as in an automatic transmission in that the cable and attached gear is supposed to run the speedometer and odometer or is it a separate set up? Did my odometer just break? Thanks in advance.
Tackelbarry is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old 06-26-2019, 08:35 PM
Senior Member
 
Woodchuck's Avatar
 
Join Date: Mar 2001
Location: Peoples Republic of Vermont
Posts: 32,710
Send a message via Yahoo to Woodchuck
Odometer busted.
j persons likes this.

Bart

What, me worry?
- Alfred E. Neuman

Woodchuck is offline  
post #3 of 12 (permalink) Old 06-26-2019, 08:46 PM
Senior Member
 
awhtx's Avatar
 
Join Date: Sep 2011
Location: The Hill Country of Central Texas
Posts: 8,815
The cable from the transmission spins a worm gear and a "flywheel" inside the speedometer. The spinning flywheel "pulls' the speedometer needle farther to the right the faster it spins. The spinning worm gear drives a gear on the odometer.
awhtx is offline  
 
post #4 of 12 (permalink) Old 06-26-2019, 10:03 PM
Senior Member
 
NEFaurora's Avatar
 
Join Date: Dec 2007
Location: Melbourne, FL
Posts: 8,346
Send a message via AIM to NEFaurora
Whatever the case... It's not an expensive fix... Unless its the gear inside the tranny.....Then you're in a whole different world of hurt..

)

Tony K.



Tony Kovar
Melbourne, FL (Formerly from Long Island, NY!)

1965 Mustang Convertible 200cid I6, 3spd Manual (Soon to be swapped for a '65 Date Coded C4!)
1966 Mustang Sprint 200 Registry Owner/Moderator
1966 Mustang Sprint 200 Convertible 200cid I6, C4 Auto
2007 Mustang V6 Convertible w/ Pony Package
MCA#70001

Getting Ready for the 2020 Melbourne, FL MCA Nationals!
NEFaurora is offline  
post #5 of 12 (permalink) Old 06-27-2019, 04:31 AM
Senior Member
 
Join Date: Sep 2016
Location: Sydney Australia
Posts: 174
Yes the speedo cable drives both the speedometer and the odometer.
Pull the dash apart, the odometer gear probably just shifted over not engaging.
They are fiddly but it can be fixed easily.

15/5/64. 260 manual Coupe.
23/3/65. 289 manual Fastback.
Tony 64 is online now  
post #6 of 12 (permalink) Old 06-27-2019, 08:14 AM
Senior Member
 
66coupe289's Avatar
 
Join Date: Sep 2001
Location: Milwaukee (Sussex), WI
Posts: 2,111
Quote:
Originally Posted by NEFaurora View Post
Whatever the case... It's not an expensive fix... Unless its the gear inside the tranny.....Then you're in a whole different world of hurt..

)

Tony K.
I cannot think of a scenario where a gear in the transmission would allow the speedometer to work and the odometer to not work. The problem is in the odometer.

I presume the speedo is running 9 mph off at highway speed. A simple change of the number of teeth on gear at the end of the cable by 12-15% should get the OP close. It's a proportional thing. Your speedo should be off by a percentage across the range. You need to adjust teeth by the same percentage. If it's registering slow you need fewer teeth on the gear and more teeth if it is registering high.
jgrote likes this.

Chris (Sussex, WI)

California car born an I6, now with warmed up 289 w/T-5z, 3.55T-loc, Granada Discs and 6 bolt Moto-Lita Steering Wheel. Owned since 1983.

Last edited by 66coupe289; 06-27-2019 at 08:19 AM.
66coupe289 is offline  
post #7 of 12 (permalink) Old 06-27-2019, 05:02 PM Thread Starter
Senior Member
 
Join Date: Jun 2018
Posts: 237
Thanks for all of the replies. Can I potentially reach and adjust the odometer gear without pulling the cluster out?
Tackelbarry is offline  
post #8 of 12 (permalink) Old 06-27-2019, 05:20 PM
Senior Member
 
Join Date: Jan 2016
Posts: 1,076
The cluster will have to come out to attempt to repair the odometer. Changing the speedometer cable gear at the transmission should be easy.
cougar70 is offline  
post #9 of 12 (permalink) Old 06-28-2019, 04:45 PM
Senior Member
 
Join Date: Sep 2016
Location: Sydney Australia
Posts: 174
Here is a little equation for the speedo correction when you get the odometer fixed.

Current gear (need to count teeny on your cable gear), multiply by, indicated speed(shown on your gauge), divide by the true speed (use gps).

15/5/64. 260 manual Coupe.
23/3/65. 289 manual Fastback.
Tony 64 is online now  
post #10 of 12 (permalink) Old 06-29-2019, 10:06 AM
Senior Member
 
Join Date: Apr 2011
Location: Poway, CA
Posts: 2,157
Cluster out,
Speedo out of cluster
Observe there is a broken plastic part.
Come back to VM and ask for source.
No body will know.
Tell you to buy a used speed.

Let's see how close my predictions are. I hope I am wrong.
Asm109 is offline  
post #11 of 12 (permalink) Old 06-29-2019, 12:36 PM
Senior Member
 
NEFaurora's Avatar
 
Join Date: Dec 2007
Location: Melbourne, FL
Posts: 8,346
Send a message via AIM to NEFaurora
If his Speedometer and Odometer are both working, then his original assumption is correct.....He just needs a different colored gear on the end of the Speedometer cable...literally a 10 minute fix under the car. He has to also take into account what his current tires/wheels combo is also as this will also affect the outcome. NPD carries the correct plastic gears...and you can go up a tooth or down a tooth...You'll have to figure that out. NPD has a chart I believe that you can go by..

https://www.npdlink.com/search/produ...t=200001&year=

Use this Speedometer Calculator and watch the videos...

https://lmr.com/products/Mustang-Spe...ear-Calculator

and..



)

Tony K.



Tony Kovar
Melbourne, FL (Formerly from Long Island, NY!)

1965 Mustang Convertible 200cid I6, 3spd Manual (Soon to be swapped for a '65 Date Coded C4!)
1966 Mustang Sprint 200 Registry Owner/Moderator
1966 Mustang Sprint 200 Convertible 200cid I6, C4 Auto
2007 Mustang V6 Convertible w/ Pony Package
MCA#70001

Getting Ready for the 2020 Melbourne, FL MCA Nationals!
NEFaurora is offline  
post #12 of 12 (permalink) Old 06-29-2019, 05:14 PM
Senior Member
 
Join Date: Apr 2011
Location: Poway, CA
Posts: 2,157
The subject of this thread and the first few words of the first sentence is.:
Help Please. My speedometer works but my odometer doesn't.

Pretty clear the cable is turning and magnet cup is spinning, but the odo isn't.

That means some iddy biddy plastic gear / shaft is busted.

Everybody has to start some place
Asm109 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Vintage Mustang Forums 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



Posting Rules  
You may post new threads
You may 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 On
Trackbacks are On
Pingbacks are On
Refbacks are Off

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