I have a 1990 f150 xlt lariat with the factory tach cluster. While driving the odometer would constantly roll over a mile every few seconds. Just a few months before it said ~180,000 miles and now it reads 244,000. There's no way I've driven that far. What could cause this?

I'd like to get it fixed so when the new engine is installed I can get an accurate reading on the new engines mileage.

Edit: is the last digit (far right) 10ths of a mile? If so I feel stupid..

 

Yes it is. Maybe you just went from 118,000 to 124,400 ?

 

That's possible...when do these odometers roll over?

 

every 100,000 miles

 

Oh wow..so I bet its rolled over at least once.

 

Impossible to tell, anything that is twenty years old I assume has been rolled over once, if it was always regularly driven probably twice. A good generalization of mileage is about 10k miles a year. Less means (to me) that it wasn't used very often/low miles for year, and more means it was a workhorse/high miles for the year.

 

I never knew that its pretty interesting. I wonder why they only put 5 digit odometers in these trucks.

 

5 digit odos were the norm until the early-mid 90s in all vehicles

but it does make it confusing on actual mileage unless you have documentation

 

So I guess my odometer does work then..and the true mileage of my truck will never be known.

 

Yeah, once upon a time trucks weren't expected to last much longer than 100.000 miles.
Guess they didn't realize people would like them enough to keep them rolling along forever.