Join Date: Nov 2000
Thanked 0 Times in 0 Posts
Re: Speedo Gear....?
Don't use a formula. Your 35" tires are not actually 35" tall and other inaccuracies. You want it closer than that. Simply measure your speed or distance accurately and compare to your odometer or speedometer. If your speedometer is reading high, because you installed numerically higher gears, you need a larger speedometer gear to slow it down. Count the number of teeth on your present gear, and proportion it up (slow the speedo reading down) or down (increase speedo reading) based on the ratio of your current readings to the actual readings. For instance, Your speedo reads 60 but you are actually going 70 because you installed 35" tires. You need to speed it up by installing a smaller speed drive gear. multiply the number of teeth on your present gear by 60/70. You can get the gears from chrysler dealorships. If it was the other way around, the speedo reads too high (you just installed 4.88 gears) then you need a larger speedo gear by 70/60 times the number of teeth on the present gear.
On the other hand, the chart may be right, but at say $20.00 a pop.... your choice.
84 CJ7, 258, HEI, M/C 2100 carb, 5 inch lift, RS9000's, 33x12.5 BFG M/T's, 4.56's and Detroit softlocker, full cage & belts, Xenon flares, Dana 44 rear, GM dual diaphragm brake booster