Hello Everyone,

I am having an issue with my Speedo it only stays on 15 mph, sometimes it'll try to catch up with it self.
Whats been replaced so far:
- Speedo Gears (ALL TESTED)
- Speed sensor
- Speed cable

I'm praying its not speedometer head, if so how do I referbish it my self.

 

Oh. Different speedo problem. What vehicle are you working on?

 

1990 f150 302 with a 5 speed manual tranny.

 

So when you are stopped it still shows 15mph? Did you try hooking up a drill to the speedometer cable to see if that makes the speedometer work?

Many years ago I sent a speedometer to Powl’s Speedometer Service to get fixed. There were several guys on JeepForum that sent gauges to D & M Restoration to have refurbished.

 

No it goes to zero at stop. But it wont hardly go over 15 mph. And it'll often be just bellow 15. Also the transmission is brand new, the shop that installed it said the speedo worked when they test drove it. Although I find that hard to believe since it did not work when we first drove it home. BTW the drive gear is green, the one in the tail shaft. Not the one on the sensor. Yes it does still work when you spin the cable manually.

 

That leads me to believe it is the drive gear inside the transmission that is the problem.

 

So how would I go about fixing that and making sure I have the right one... My rear gear ratio is 3.08. Gear is green too..

 

How to make sure you have the right gear inside the transmission tail housing? With the speed sensor removed from the transmission can you turn the gear by hand or does it feel locked in place?

 

I havent tried that, what will that tell me?

 

If the drive gear is being turned with the transmission output shaft or spinning freely on the shaft.


This is assuming you have a two wheel drive truck since you haven’t mentioned a transfer case.

 

Ok so it it spins freely its bad? Also still havent had time to check, been busy with fire wood. Also what tool what should I use to see if it spins?