Speedometer destroying its self (1 Viewer)

[Sean Foster]

so this morning I started my 91 at about 10° f and when I started driving I got a scraping noise from the back right corner, I got out and checked to see if it was ice buildup on the arch, I didn’t find any but I assumed there was some on the back of the wheel so I kept driving. Once I got passed 10 mph the dash started making a whining sound and once i got on the highway doing 30 the sound changed to a grinding sound and bounced between 30-60 and sometimes it would fly all the way to 110, and ideas or suggestions would be greatly appreciated

 

[jonheld]

so this morning I started my 91 at about 10° f and when I started driving I got a scraping noise from the back right corner, I got out and checked to see if it was ice buildup on the arch, I didn’t find any but I assumed there was some on the back of the wheel so I kept driving. Once I got passed 10 mph the dash started making a whining sound and once i got on the highway doing 30 the sound changed to a grinding sound and bounced between 30-60 and sometimes it would fly all the way to 110, and ideas or suggestions would be greatly appreciated

Replace your speedometer cable.

 

[Sean Foster]

Replace your speedometer cable.

Would be just be that? I parked it the day before no problems and then instanly went to this today, I’ll deffinetly look into a new cable though

 

[jonheld]

Would be just be that? I parked it the day before no problems and then instanly went to this today, I’ll deffinetly look into a new cable though

Your speedometer cable is 27 years old. When it gets cold, it will begin to bind on the sheath where it has worn through. This will create a racket behind the dash as the sound is transmitted to the back of the speedo. As you drive, the inner cable is wrapping on itself and periodically unwrapping very quickly, which shoots the needle up to unprecedented speeds for a 3FE. Eventually, the cable will fracture as it wears completely through the outer sheath.

As an interim "repair", you could disconnect the cable from the speed sensor on the side of the transfer case, grab the inner speedo cable with pliers and pull the inner cable out of the sheath. Clean it with the solvent of your choice, dry it, and coat it with light duty grease and reinstall. As you get to the last inch or so, you'll need to rotate the cable so it seats into the speedo mechanism. This may or may not help.

 

[Sean Foster]

Your speedometer cable is 27 years old. When it gets cold, it will begin to bind on the sheath where it has worn through. This will create a racket behind the dash as the sound is transmitted to the back of the speedo. As you drive, the inner cable is wrapping on itself and periodically unwrapping very quickly, which shoots the needle up to unprecedented speeds for a 3FE. Eventually, the cable will fracture as it wears completely through the outer sheath.

As an interim "repair", you could disconnect the cable from the speed sensor on the side of the transfer case, grab the inner speedo cable with pliers and pull the inner cable out of the sheath. Clean it with the solvent of your choice, dry it, and coat it with light duty grease and reinstall. As you get to the last inch or so, you'll need to rotate the cable so it seats into the speedo mechanism. This may or may not help.

Will do, thank you so much

 

[Sean Foster]

Your speedometer cable is 27 years old. When it gets cold, it will begin to bind on the sheath where it has worn through. This will create a racket behind the dash as the sound is transmitted to the back of the speedo. As you drive, the inner cable is wrapping on itself and periodically unwrapping very quickly, which shoots the needle up to unprecedented speeds for a 3FE. Eventually, the cable will fracture as it wears completely through the outer sheath.

As an interim "repair", you could disconnect the cable from the speed sensor on the side of the transfer case, grab the inner speedo cable with pliers and pull the inner cable out of the sheath. Clean it with the solvent of your choice, dry it, and coat it with light duty grease and reinstall. As you get to the last inch or so, you'll need to rotate the cable so it seats into the speedo mechanism. This may or may not help.

Will do, thank you so much

 

[BILT4ME]

Will do, thank you so much

The "light duty grease" Jon refers to is usually White Lithium grease. They used to make an actual "speedometer cable lubricant" for all the older vehicles. I still have a tube of it that I use for my Studebaker and 70 GMC.

The GM and Stude speedo cables come out from behind the speedometer, whereas Jon (The Guru) advises that the speedo cable on yours comes out from underneath.

I pull it out and clean it with Brakleen. Then I dry it and place it in a gallon Ziploc freezer bag, then slobber a gob of grease into the bag and rub it on all the cable by hand. Then I try to squirt a bit of grease into the cable sheath before I push in the cable. I also keep lubing the cable as I push it in. Sometime I will pull it out a few inches, then place more grease on it and push some more in order to get as much grease to the higher parts of the sheath as possible.

Do NOT spray Brakleen into the cable sheath.