Lifted truck problems

Thanks ill look into that. For now ive just been using gps as well

 

I'm usually 3-5 mph off. I tend to keep my speedo around 65 if I'm supposed to be at 70.

 

Yea i did the same. Prior to the regear i was off by 5mph when i reached 70 due to the 35" tires.

 

After re-gearing I was off by at least 10 mph

 

Odd. I was under the impression that our Tundras use wheel speed sensors to generate speedometer numbers. In other words, the speedometer doesn’t change when you regear.


I went to 34” tires a year ago, and my speedo was obviously off because the tire diameter changed. I went with a RC speedometer calibrator to get it back to accurate, and eventually installed 5.29’s. Speedometer stayed the exact same, but I gained rpm at the same speeds.


The only thing that doesn’t match is the displayed cruise control speed doesn’t match the speedometer. The RC calibrator doesn’t fix that…. So, if I’m going 65 and turn on cruise control, the CC reads about 60.

 

Does using the speefometer count as a tune and thus void the warranty?

 

If that is the case, then why is the calibration software using gear ratio and tire size for speedometer corrections?

 

That’s a good question, but it may be a case of a somewhat generic software. Many vehicles read speed off the transfer case output shaft, so gear ratios would certainly make a difference. If I remember correctly, I was told to leave my gear ratio set to 4.30 after the gear change. This would explain why some folks see wildly different results after gears and calibrators.


I’ll see if I can track down the thread where this was explained!

 

Like any warranty concern, they’d have to find a way to prove that the modification created the problem and caused a failure that you’d like covered under warranty.

I don’t see how a speedometer calibrator could cause any warranty concerns. If the claim is for a part in the drivetrain, suspension, or steering, the larger tires that made a speedometer calibrator worth while would likely be a point of leverage for the dealer to use for claim denial.

If your radio dies and they claim the calibrator caused it, I’d push back. Those two parts should not cause problems with each other. Same if it were your window switch.