I have been googling my ass off, but can't come across the reference chart for selecting the appropriate speedo gear by tire size and gear ratio. Somebody help a poor dude out here, I gotta get the speedo back into the ballpark.
Jerry
Jerry Newton did pass the time by typing:
?
Just a follow up to that chart. You can do it mathematically as well using the formula:
Gear Teeth = Axle ratio * 280 / Tire Diameter
Chris
Thanks to all, I have what I need.
Jerry
Raingler's chart is OK, and I've seen others, but none of them specify which year TJ/YJ they are talking about. I've seen references suggesting the older TJ's have a stock 27 tooth gear, but my 2004 TJ has/had a 29 tooth gear. When I timed it on the road and did the math, I needed a 35 tooth gear.
the math:
3600/mile time= miles per hour (mile time=time in seconds to cover a mile)Number of gear teeth=(old gear number)x Speedo reading/actual speed.
(ie--if the actual speed is lower than the speedo reading, you end up with a larger gear).
I usually average the times over 2-3 miles using mile markers on the highway.
tim
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.