jason0341

I am about to change my tires size so my speedo and shift points will adjust accordingly. Do I need to put in 3.73's for the axle option or should it know that already since it's factory?

Marshall

You will have to insert your gears and actual tire size to make it accurate. It has the equation on the set up sheet. Make sure to use the actual size of the tire not what it marketed as. Very easy!

jason0341

OK thanks, didn't know if I had to enter the gear size or not.

Sent from my Supersonic EVO 4Gees!

Deere_Jeep

OH Crap.. I never thought of that, guess I'll put it on the list for tomorrow.. I did the tires but never thought about gear since I'm stock

jason0341

Yeah same here, not sure if it was needed or not since I was still stock too!

Sent from my Supersonic EVO 4Gees!

nthinuf

The ProCal lets you program in 'new' data. Your computer already knows you have the 3.73's, so you only need to tell it you have a new tire height.

Tails

I also think this is correct. All you need to do is set the first three dip switches, down-down-up for tires up to 38". Then write your tire measurements on a piece of paper and subtract 24. Assume a 33" inch tire isn't quite 33 and a 35 isn't 35, but a little smaller. As the quick reference guide says, for instance, use 34.75 - 24 = 10.75. Then set the rest of the dip switches according to the guide.
Then plug in with the engine off and ignition on. Horn will sound twice.

I then drove a bit with my GPS on to see if the speedo was accurate. A car navigation unit gives you the exact speed, so it's easy to compare and possibly adjust a bit.

jason0341

Yeah I am cool with setting everything, I just didn't know if it was needed to put in the axle ratio. It never specifies in the booklet, I figured it probably knows the stock setting of 3.73's or whatever the Jeep comes with. I guess it can't hurt to just set it for the axle ratio anyways

raidue

Yeah if u have an auto u need to set your gear ratios for the shift points if u have a 6-spd then it's nit necessary to adjust.

redrunner

I do not agree with the advise to indicate gear size with the Procal that has not changed. Why would you need to use the procal to say you still have the same gear size? That does not make sense. Are you also going to tell it you still want daytime running lamps off etc.? Should be adequate to just alter tire size if that is all that changed. The Procal simply has the capability to alter some PCM code parameters if you indicate through the dip switches that you want them changed. If the dealer reflashes, Procal changes will be overwritten and you will then need to respecify them again using the Procal.