Speedometer

[TJ_Jeep]

When putting bigger tires on a 98' Wrangler do you have to recalibrate it? Some say you do and some say you don't the reason I'm asking because i got pulled over the other day and the cop said i was doing 63 when my speedo said 55. now is mine wrong or his?

 

[SteelHeadz]

The Bigger tires will give you a lower speed on the speedometer than the actual speed. there are several modules out there that you can install to correct that. i've used a module from Jet Performance from 4WD.com. I installed it on my Friends TJ.It's simple and pretty close to accurate.

 

[southtj]

Yeah, 35s would definitely throw of your speedo. You can get get a new speedo gear from Quadratec here.

They have a chart here that will tell you what gear you need depending on tire size and gear ratio.

 

[Bounty__Hunter]

I have a bunch of speedo gears available if you want to work something out. Just email me at bountyhunter AT sija.org.

Or for $80 you can install this speedo interface and be able to correct your speedo regardless of tire size or gearing: Universal Speedometer Signal Interface