LBZ gear change

I've got a customer running 4.88 gears on a LBZ. Anyone tried changing H0103 then putting in the actual tire size and have it work.

Or should I just do the calculations and leave the gearing stock?

Thanks,
Rob

I still didnt get it to work, I had to use my GPS and lots of trial and error, what size tires is he running? if its 285's (which I doubt) I can post the numbers for you.

37". I'd think there is some kind of calculation, but not sure about converting it to LBZ "tire rev. per mile"

yeah i had that problem, it changes a few value but not all. I just used the GPS and thats about all i could figure out...sorry i cant help more :(

Thank-you for the help. I did find a speedo calc. that you can import gear ratio, tire size, and RPM, and it gives you speed.

I then just did some math to find the difference and then modded it for stock gearing and the matched tire size to = the same MPH.

I did one last week. 37" with 4.56 gears. I entered the gear ratio and then corrected the tire size.

A Tech 2 to reprogram the ABS to 285-75-16. Quick trip around the block to verify with a portable GPS and off he went.

Thanks for the Info on this guys. Perfect timing as I just swapped in 4.56s on my setup (today) with 37s and changed H0103 to 4.56 and H0136 to 570 ( from stock 682) and it's perfect as far as my GPS is concerned.

I did the Tech 2 trick a couple of years ago and so far no abs lights or CEL/DTCs.