Speedo Gear for 265/70/16 and 4.11

OK, just checked the charts available and have found three different answers. I have 265/70/16 tires which measure out at 30inches with a tape, but are advertised as the same as 31x10.50's. I will be switching to 4.11 gears. Depending on the chart, I need 36, 37, or 38 tooth gear. Allright then anybody really know?

Thanks, Angus

38 tooth for a 31" and 4.11/4.10's

Don't mean to hijack, but what about using stock gears and 31x10.5x15? It will eventually be locked if that matters.

woody431 said:

Don't mean to hijack, but what about using stock gears and 31x10.5x15? It will eventually be locked if that matters.

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Which stock? 3.07? 3.55? 3.73? (I guess not 411's as that was the original question)

I'm not sure what woody meant, but it is allready locked and I am using "stock" 4.11's? Anyway just thought others may have found multiple answers like I have.

Oh, my bad. I have a 95, 8.25 and D30, 3.55 gears, will have 31x10.5x15's and probably No-Slips.

What brand are you going to buy? The true height will be different according to who has made them and in the larger sizes can even be 3/4" different from one brand to another with the same size on the sidewall!
I have my chart made up to suit BFG's so even if you buy another brand you can cross refereance the true heights between them.

http://go.jeep-xj.info

I do have BFG's. 265/70/16 measure out to be 30 inch's but compare on the specs to 31-10.50. I have ended up getting a 37 tooth gear since the dealer doesnt have a 38.
Angus

The most accurate method of calculating the number of teeth needed is to use a GPS. If you don't have one, I'm sure one of your buddies has one he wants to show off. Then go drive at a given speed according to the speedo and then see what the GPS says. Pull the speedo gear and check the number of teeth. The change in number of teeth is inversely proportional to the error in the speedo. So:

Speedo Speed . New # teeth
--------------------- = ------------------------
GPS Speed . Existing # teeth

Charts are fine, but this will give you the absolute best answer and you don't
have to worry about any axle ratios and tire sizes.

Kejtar said:

Which stock? 3.07? 3.55? 3.73? (I guess not 411's as that was the original question)

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HELP ME KEJTAR!! I have 3.07 gears and wanna run 31's but the list in search said my tooth count goes down... don't understand...

you want a 27 tooth gear... now calm down...