Which Diff Gears to use
 

I have an 1987 toyota Truck...a little moified, has a 22re with an auto trans. I Have 33 or 34 inch tall tires, depends on where you measure from, Which gear do I use, 4.88 or 5.29. This will be off road only. I have a 83 inch wheel base, and need a little zip. Thanks

22re with auto and 33's/34's? If you were gonna drive it on the street and needed a functional overdrive, I would actually say 5.71.

For an offroad only truck, though, I would look at changing the tcase - either add a crawler or change to a 4.7 ratio.

83" seems awfully short - did you shorten the wheelbase, and why?

don't they say not to use anything over 5.29, because the teeth are too small, or there is only one tooth in contact with the pinion at a time or something like that?

With an auto tranny, 5.29s will do you well. 83 inch wheelbase is "tight" for sure.

Gears: http://www.wabfab.org/products/diffe...ferentials.htm

:guitar:

Both 5.29 and 5.71 have 7 teeth on the pinion. you should always have 3 teethe in contact, but the lower gears are MUCH more critical of setup to make sure that happens. Check out www.gearinstalls.com for more low-gear-toyota info

Here's a nice calculator I found...

http://www.izook.com/gearcalc.htm

Don't know how accurate it is. Should be simple math though.