Re: Rear end ratio ?

Posted by Joe Santana On 2011/10/9 22:20:06

The clueless here. My speedometer is off by 10 or so miles too low also. So I jacked up one rear wheel, turned it one full turn and counted the drive shaft turns, which were 2. But if I divide by 2, I get 1. That didn't seem right. So I checked my owner's manual and the standard ratio for a 40 1803 is 3.92 or (with Econo-drive 4.36 or optionally 4.09. So I think you would multiply rather than divide in order to get to 4. This is totally based on knowing the correct answer, and not on understanding how it works.

My solution is to take it to a speedometer shop, where for $170 they will check it and install the correct number of teeth so it will read my speed correctly. No longer will I be able to get out of a ticket because of it.

" Yes, Officer, thank you. I will put a 5th wheel on it."