Jumpin' Speedometer

[Donell 61]

Hello I'm new to the forum, thanks for the hellos! I own a 1990 4x4 regular cab P.U. The speedometer started jumping around when I'm driving. I replaced the plastic gear that enters the transmission with the part my transmission guy suggested and it dosen't help. Any suggestions?

 

[Brain75]

I saw this a ton in the 80's ford F-series (all farm trucks) it's in the speedometer itself if it is the same issue, back in the 90's it was just as cheap to replace the speedometer as to fool with disassembly... did you try rock auto / partsgeek / etc?

At slow speeds it makes a slight grinding noise at highway it wags back and forth like a dogs tail between 45 and 65 or similar, right?

 

[Donell 61]

Will do, Thanks

 

[Donell 61]

Yes it does

 

[Snoranger]

Usually when the speedometer needle bounces it happens at higher speeds 45MPH +. The most common reason is the cable.
The cheapest way to test is to pull the cluster and spray some lube down into the cable, put it back together, and see if it’s any better. If it is, replace the cable before it starts acting up again.

 

[SenorNoob]

I have lubed my cable twice a year for several years now. I need to replace it before they are NLA. It does it more when it's cold for some reason.

 

[scotts90ranger]

I happen to have a spare cluster with speedo, it would take me a bit to get to but I'll try to remember to dig it out... Since you're local and all

 

[Donell 61]

Excelent, let me know!

 

[lil_Blue_Ford]

Moving to the appropriate section…