[99wrangler4x4]

i want to thank everyone for answering all of my questions but now i have two more. i got my tires on today 305/70 16 but have not ordered the speedo gear so does anyone have a clue of how much faster im going than what the speedo says? and my second question is about the transfer case lowering kit. the bolt holes do not line up (yes i have them on the right way because if i turn them around the holes would be way off) so i could either drill them right or leave them off. i heard if i leave them off it will cause vibrations- are the vibrations really bad? and will it cause too much stress on my drivetrain?

[JEEP97TJ]

Originally Posted by 99wrangler4x4

i want to thank everyone for answering all of my questions but now i have two more. i got my tires on today 305/70 16 but have not ordered the speedo gear so does anyone have a clue of how much faster im going than what the speedo says? and my second question is about the transfer case lowering kit. the bolt holes do not line up (yes i have them on the right way because if i turn them around the holes would be way off) so i could either drill them right or leave them off. i heard if i leave them off it will cause vibrations- are the vibrations really bad? and will it cause too much stress on my drivetrain?

I just moved up tire sizes too. Now, did you change axle gears when you changed tire size also?

Correct speed (with same gear ratio) = new tire diameter/old tire diameter
x speed

For me, 31 inch tire / 28 inch tire x 70 mph = 77.5 mph.

[99wrangler4x4]

nope. same gear ratio. that equation helped alot!