Hey all, I have a new to me 2007 JK Sahara (details in bio). It came with 35's and I just went down to 33's as it's better for my preference. Everything has been fine, speedometer is off by about 2 mph, but the main thing I'm noticing came from doing some driving in the mountains. The shift points just didn't seem right. For daily driving, I didn't notice it, but in the mountains it was not shifting soon enough traveling uphill.

I'm looking at the Superchips Flashpaq to adjust the computer for the tires and gearing, wondering if that adjust shift points too? Aside from the Flashpaq, any other recommendations? That seems like it does it all. I

 

Welcome Matt. If you are just focused on Tire size and Gearing (was gear ratios changed to your knowledge) you can do this with Jscan.. JScan ? OBD JScan ? Mobile Jeep, Chrysler, Dodge Diagnostic Tool It does many functions and is not expensive.. It is what is in my toolbox used on our JKU and JT Mojave.

 

Thanks for that, definitely a less expensive option. Gearing was changed to 5:13 accommodating 35” tires. But I also want to see if I can’t adjust the shift points so it behaves a littler better.

 

Nobody is digging as deep as to mess with shift points on these things. Adjusting for tire size is good enough for 99% of owners. I'd suspect maybe HP Tuners can adjust shift points but you are looking at a ton more money and required skill/knowledge for use, and the benefit is not going to be worth that IMO. Taking it somewhere with the software and paying for them to do it could be an option, though my issue with doing something like that is always if you have to jack with things in the future it is a major headache. If I can't do it myself, I'd rather not have it done to my rig; otherwise, it is a future issue waiting to happen.