With the gear and tire change, the LJ's speedometer was inaccurate. This effects not only the speedometer and odometer readings, it changes transmission shift points, in this case making the tranny upshift too early.
In the old days, we'd do some math and hope there was a speedo drive gear that would correct the problem. Today, there are a number of solutions, most of which require wire splicing and trial and error to get the correct speedo reading.
Enter SpeedoHealer by Heal Tech. Originally designed for motorcycles, Blue Monkey Motorsports offers a plug-and-play SpeedoHealer for TJs, LJs, and XJs. Installing and using the SpeedoHealer is as simple as plugging the SpeedoHealer plug inline at the speed sensor on the transfer case, running the wire to the firewall by the battery, and mounting the small box on the firewall (in our case, next to battery).
Following simple instructions, it's then easy to program the SpeedoHealer to correct the speedometer reading. The SpeedoHealer offers A and B correction calibrations, so if you run different tires for the mud/rocks and street, it's easy to switch when tires are changed.
As mentioned, there are no wires to splice and no trial-and-error programming. The SpeedoHealer is truly plug-and-play.
Our transmission shifts when it should and the speedometer is correct again. SpeedoHealer works.