The speedometer on my 91 LX is pretty messed up. It only works below 30MPH after that it just shoots up to 65MPH and hangs around there. Does anyone know what could be causing this?

 

either the speedo cable is worn out. or the speedometer gear has missing teeth. did the guy say if the rear gear was ever changed???

 

Nope, the rear gear is stock.

 

I had a similar problem in one of my Capri's. The cable was loose and I replaced it. Everything worked after that. Not sure if that helps? Can you hear any "clicking" sounds from the speedo?

 

No clicking sounds but I am going to get in and take a look at that cable as soon as I get a chance.

 

I am having the same problem with mine, it is a 91 aswell, it gets all messed up once i hit 120 km/h. Before it wasnt working at all and had to reconnect the cable on the back of the speedo. Not sure y it is messing up now havent had time to look at it.

 

I've got the exact same problem. Up to about 35 it's ok, but jumps around a little bit. At 70, it says I'm doing 140+

Anyway, I've replaced the speedo drive gear, the speedo gear, and the speedo cable. The only thing left is the speedo head.

I'm wondering if there was a problem with the speedo heads on the 91. Mine has already been replaced once by a previous owner. I guess I'll be doing it again soon.

The tach doesn't make the best speedometer.

 

I had a bouncy speedo that was driving me crazy. I put some graphite between the cable and outter sheath and this fixed the issue for a good while. It's starting to happen again so I might change out the cable soon.

 

mine is making weird noise once i get over 120 km/h, it makes a weird squeecking noise and bounces all over, says I am doin 160 km/h when i know that I am going no where near that

 

On my 88 it makes some noise once in a while, but has always worked fine. I'll get around to looking at it one of these days.

 

sounds like your speedo head is worn out you could try pulling the head unit and in back you will see where the cable turns the head (it works like a cintrifical clutch) try putting a little oil (like sewing maching oil 3 in 1 oil) in it if its making noise

 

On early models mustangs (falcons, and probably other fords), you can pull the cable itself from it's sheathing/insulation, and wipe it off with a rag. Then squirt some graphite down into the sheathing/cable insulation and reinsert the cable.

Don't know if late models are them same type of set-up. Are they?

 

they are if there still mechanical they do make the correct lube for it and you can find it at the local parts slinger allso some white litium grease will work too (dont use to much)

 

where i live theres lots of salt on the roads in the winter months and underneath the driver floor pan theres a litle steel clip which holds the speedometer cable in place of corse it rusted and shifted places where it bends and luck haves it it rubs against the catalic converter and burns in no time no speedometer just check that might save a few speedometer cables 100$ each check it out never know it might be yout problem B)