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Fox Body Mustang Speedometer Cable Install (79-93)

Created by Jay Walling
Date Created: 3/13/2019
Last Updated: 5/17/2021

Follow along as we show you how to fix your jumpy speedometer needle in your 1979-1993 Mustang Fox Body!

Viewing this install and using the information shared is subject to the terms set forth here - View the LMR Install Instructions Disclaimer.

Have you recently replaced a driveline component and now your speedo is jumpy or simply not working at all? This is normally going to be the speedometer cable that is the culprit. This cable is the mechanical link between the output shaft of the transmission and the cluster assembly in your Mustang. The following steps will go over this install and show you what goes into this removal and installation.

  1. Remove the negative battery cable from the car.
  2. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  3. Remove the upper and lower steering column shroud.
  4. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  5. Remove the screws that are holding in the lower dash.
  6. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  7. Remove the lower dash metal support plate.
  8. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  9. Using a flat bladed screw driver, pry the tabs on the headlight switch away from the upper portion of the dash and unplug the electrical connector. Do this same step on the opposite side for the emergency flasher switch.
  10. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  11. Remove the 4 cluster surround screws can carefully remove the surround from the car.
  12. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  13. Now, remove the 5 gauge cluster attaching screws from the cluster.
  14. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  15. Once these have been removed, pull the gauge cluster forward and disconnect all of the electrical connections.
  16. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  17. To remove the speedometer cable, squeeze the clip and pull it away from the cluster.
  18. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  19. Moving to the underside of the hood, locate the cable and the grommet on the firewall. Pull the cable out of the grommet and then remove the old grommet from the firewall.
  20. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  21. Next, support the car with either a lift or jack stands.
  22. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  23. Locate the cable and pry back the metal body clip holding the cable in place.
  24. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  25. Remove the retaining bolt that is securing the cable to the frame rail. Pull the cable down and underneath the car.
  26. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  27. Remove the retaining bolt that is holding the cable onto the tail shaft of the transmission. Pull the cable from the car at this time.
  28. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  29. Once the cable is removed, take it to your workbench. Using a flat blade screwdriver, pry the cable bracket from step 13 off of the old cable. Clean this bracket and then set it aside.
  30. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  31. If equipped, remove the speed sensor from the end of the cable. Using a small pick or needle nose pliers, remove the clip holding the sensor to the cable. Clean the sensor using a quality electric parts cleaner or comparable solvent.
  32. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  33. Lubricate the cable by removing the cable from the outer conduit. Use a quality cable lube such as P/N LRS-03344 and lubricate the cable from end to end, do not be shy, a lack of lubrication can cause a jumpy needle after the install.
  34. Reinstall the speed sensor and place the clip back into place.
  35. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  36. Use this time to inspect the speedo gear, replace if need be.
  37. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  38. Route the cable back over the frame rail and then reinstall the previously removed cable bracket. Position the bracket into place and reattach it to its factory location.
  39. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  40. Slide the cable back into the metal retaining clip.
  41. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  42. Secure the cable or the speed sensor back on the transmission using the retaining bolt.
  43. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  44. Pass the cable back through the firewall with the grommet.
  45. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  46. Back on this inside of the car, pass the cable back through the dash.
  47. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  48. Reconnect the cable and the electrical connectors back to the cluster and reattach the cluster using the 5 bolts.
  49. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  50. Reinstall the surround, support plate, lower dash, and column covers.
  51. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  52. Reconnect the negative battery cable.
  53. Fox Body Mustang Speedometer Cable Install (79-93) - Fox Body Mustang Speedometer Cable Install (79-93)
  54. Take the car for a test drive and check for proper operation.

Great job! You now have a properly functioning speedometer back in your Mustang. To see more how-to and review videos covering industry leading products, be sure and subscribe to our YouTube channel. While you're at it, check out our other videos and shop LMR.com for all of your 79-present Mustang parts and SVT Lightning needs!


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About the Video

1979-1993 Mustang Speedometer Cable & Gear - Review & Install

Check out our YouTube channel for even more tech tips, installation videos, how-tos, and more. The best place to go for anything Mustang related!

Published on 2016-12-19
If your speedometer (with speed sensor) is not reading or the needle is jumping all over the place, chances are you need to replace the speedometer cable. This Mustang Speedometer Cable is a direct replacement for 1979-93 Mustangs with cruise control and/or EFI (electronic fuel injection). This Mustang speedometer cable replacement does not include the firewall grommet; you must re-use your original.

If your speedometer (without speed sensor) is not reading or the needle is jumping all over the place, chances are you need to replace the speedometer cable. This reproduction Mustang speedometer cable is a direct replacement for your 79-85 Mustang with carburetor and without cruise control. The cable to transmission o-ring & firewall grommet are not included.

Mustang Fitment: 1979-1993 Mustang with speed sensor.
1979-1985 Mustang with carburetor and without cruise control.

Speedometer Cable w/ speed sensor:
LRS-17260B

Speedometer Cable w/o speed sensor:
LRS-17260A
Transcript
How’s it going everybody? Landan with Late Model Restoration. This video will cover my quick overview and install on these replacement speedometer cables designed for the 1979 to 1993 Fox Mustang.

The speedometer cable starts at the back of the gauge cluster, exits out of the firewall, makes its way down the underside of the car making its final stop at the transmission. This cable is needed to translate drivetrain revolutions into a numerical, easy to read number so you know just how fast you’re going.

Often times, a tell-tale sign of a defective speedometer cable is a jumping or unstable needle, or you simply don’t have a reading at all. Each of these cables are a direct replacement for their intended applications.

Of the two variants the first cable is designed for 1979 to 1985 carbureted Mustangs without cruise control. This cable measures in at approximately seventy-six inches. For some reason your 79 to 85 car is equipped with cruise, you’ll need the cable that is designed for the speed sensor.

Speaking of the speed sensor, all EFI or fuel injected Fox Bodys came equipped with a speed sensor. Whether it has cruise control or it doesn’t, from the factory those care were equipped with a speed sensor. This particular cable designed for the speed sensor equipped cars measures in at approximately seventy-one and half inches.

Before installing the cable into your car, it is required that you remove the cable from the outer sheath and use the provided lubricant to lube the cable. Once that is done, simply slide the cable back into the sheath. Failure to do this will cause a jumpy speedo needle and will result in premature cable failure.

I’ll be doing the work on a 1988 coupe so some things will obviously differ depending on your car.
To remove your old cable, begin by removing the upper and lower steering column trim pieces.
Next, remove the retaining screws securing the lower dash.
Set the dash piece aside and remove the lower metal support plate.
Set this aside and then grab a flat head screwdriver.
Use this screwdriver to release the tabs from the headlight switch and emergency flasher switch.
Carefully pull them forward and disconnect the electrical connections.
Go ahead and remove the four cluster surround screws.
There will be two on the bottom and two on the top.
Carefully remove the cluster surround from the car.
Now, remove the five attaching screws that retain the gauge cluster to the dash.
Once removed, pull the cluster forward and disconnect the electrical connections.
To release the speedometer cable, squeeze the white clip and slide it out of the cluster.
Set the cluster aside.
Pop the hood and locate the cable at the firewall.
Pull it out of the grommet and then remove the grommet.
In our case, this one was totally dry rotted and will need to be replaced along with the new cable.
We carry both automatic and manual speedometer cable grommets at LMR.com
Grommet locations are different depending on the transmission in our Mustang.
If you have a manual transmission the speedo cable enters just to the left of the clutch cable and throttle cable.
If you have an automatic transmission, the speedo cable enters where the clutch cable would be.
Support the car via a lift or jack stands.
In our case, we removed the mid-pipe to provide a better understanding.
The mid-pipe does not have to be removed to service the speedometer cable.
Pry back the metal body clip to free the cable.
Remove the retaining bolt that secure the cable to the frame rail via a cable bracket.
Pull the cable down and under the car.
Remove the retaining bolt that secures the cable to the transmission.
Slide the cable out of the transmission and remove it from the car.
Pry open the cable bracket, clean it and set aside.
If your car is equipped with a speedometer cable, pull up on the hair pin clip and slide the sensor off of the cable.
Clean the sensor with quality electric parts cleaner.
Slide the new cable into the speed sensor and secure it with the hairpin clip.
Now would be a perfect time to switch out your speedo gear if you have to.
In case you didn’t know, speedo gears with a longer shaft are for automatic transmissions while gears with a shorter shaft are for manual transmission.
If you need to change speedo gears, pry off the retaining clip and then remove the gear from the cable or speed sensor.
Thoroughly clean the area and use the provided cable lubricant to lightly lubricate the cable shaft or speed sensor shaft.
Slide on the new gear followed by the retaining clip.
From underneath the car, route the cable towards the top of the engine.
Install the previously removed cable bracket.
Position the bracket on the frame rail and retighten the retaining bolt.
Slide the cable back into the metal clip.
Locate the end of the speedo cable that plugs into the gauge cluster.
Carefully remove the cable from the outer sheath.
Use the provided lubricant and lubricate and entire cable.
Now you can slide it back into the outer sheath.
Underneath the car, slide the speed sensor or cable into the transmission.
Secure the cable or speed sensor with the retaining bolt.
Make sure the frame rail bolt is tight and you’re done working underneath the car.
Before you stab the cable through the firewall, double and triple check the cable to make sure there is plenty of clearance between it and any exhaust component.
Pass the cable through the firewall.
Take this time to install a new firewall grommet.
If you have a car with a speed sensor, you can slide the grommet over the cable first.
Now, if you have a car without a speed sensor, you’ll have to cut the grommet, slide it over the cable and then plug it into the firewall.
From inside of the car, finish passing the cable through the dash.
Grab your cluster; plug in the electrical connections and speedometer cable.
Retighten the retaining screws.
Reassemble all of your interior pieces and plug in the negative batter cable.
Take the car for a quick spin to verify everything functions properly.
After that, you’re all finished.

Alright fellas, as far as installation goes, you can probably bet on roughly two hours. Switching out speedometer cables and gears is very straightforward. Other than the cable, I would recommend a new firewall grommet and take this time to verify the speedometer in your car is reading properly. If not, use our speedo gear calculator to help you pin point which gear you need for your application.

Until next time guys, go ahead and subscribe to our YouTube channel for more content covering the Fox Mustang. Be sure and pick up a speedometer cable, gear and grommet from the real Fox enthusiasts, LMR.com!
Thumbnail image of the author of this article, Jay Walling.

About the Author

Jay has written content for Late Model Restoration for over 10 years, producing over 120 articles. Jay has an extensive 25-plus-year background in automotive and is a certified Ford Technician. Read more...