So..

 

Any reason for my speedometer to suddenly start reading well over actual speed? I'm talking like reading 60. but only going 40 type of error.

 

My car is a '74 subaru GL (1400)

 

Thanks,

Older spedos are really quite simple. They are a spinning magnet is a bell shaped drum. The needle is attached to the drum and the faster the magnet spins, the higher it reads.

 

What throws off a spedo (this much) is a worn cable, or mechanical malfunction. When the cable starts fraying, it will wind up and release, therefor showing a much higher speed then you are actually going.

 

Inspect your cable.

 

nipper

Older spedos are really quite simple. They are a spinning magnet is a bell shaped drum. The needle is attached to the drum and the faster the magnet spins, the higher it reads.

 

What throws off a spedo (this much) is a worn cable, or mechanical malfunction. When the cable starts fraying, it will wind up and release, therefor showing a much higher speed then you are actually going.

 

Inspect your cable.

 

nipper

 

What are these cables lubed with? graphite?

Another thing that can happen is the seal around the base of the speedo cable can break where it goes into the tranny and it'll actually suck up some gear oil to cause it to read differently. It should just be lubed with a thin oil like mineral oil. Best thing to do is to replace it because it'll eventually break on you and leave you without a speedo/odometer. I think they can be had on ebay for pretty cheap.

Another thing that can happen is the seal around the base of the speedo cable can break where it goes into the tranny and it'll actually suck up some gear oil to cause it to read differently. It should just be lubed with a thin oil like mineral oil. Best thing to do is to replace it because it'll eventually break on you and leave you without a speedo/odometer. I think they can be had on ebay for pretty cheap.

 

i just had my cable brake on my 1400.

bit annoying when you dont no what speed ya doin