Tire Size + Gearing Debate Time

[WASURF63]

Quote: ntsqd
Simpler way to do this is to draw a straight line down the drive shaft, then tape a piece of string to the drive shaft right at the drawn line. Rotate the tires one exact revolution. Look at how many times the string crosses the line and what the partial revolution is.[/QUOTE]

ntsqd,

Very clever! Thank you.

WS

 

[WASURF63]

Your truck came with OEM 3.73 gears same as mine did.

All trucks of this vintage are 3.73 with the exception of the 2.7 L 4 cylinder which has 4.10's from the factory.

Thanks again Doc,

This is what I thought all along. I was half way sure that you'd also replied with this info to a similar posted gearing question a while back. Someone asked about power loss when going to 33's or a 255/85 tire.

Gracias,

WS

 

[xcmountain80]

Most calculators are built by Jeep guys who have larger displacement engines. I started on the ORC Yota email list in about '98. The common advise for 20/22R trucks since that time has been 31's = 4.56's, 33's = 4.88's, and 35's+ = 5.29's

My speedo reads +/- 2MPH of true (checked with a GPS and with mileposts) with 33's and 4.88's.

Were it me, I'd run the 4.56's and some 31's or 235's. They're also less spendy tires to replace while still in college.

Ohh to small to small I won't drop under the a 285 (on this vehicle). I have a line on reasonably priced 4.88's, a front third already loaded with 4.88's a buyer for the front set of the reasonably priced 4.88's and a shop that will just do the gears setup on my rear third (I'll pull it and install it.) As for tire cost the Nitto TG's in the 295 flavor are usually reasonable and last for 40-50k miles, so I replace the about every year and a half. I've heard some crazy number associated with with 5.29's and 33's but I will start a different post about my gear selection.

A