This is my fuel gauge that was about 1/4 off from full. Was curious if there was an adjustment inside. As you can see there are 2 small access holes with gears or teeth. Sort of like the adjusters on drum brakes. I moved the lower left adjuster to move the red needle clockwise to compensate. Now, I haven't installed it yet but I'm pretty sure it'll make it a difference. I've searched internet and there's no mention of actual adjustment to the gauge. Hope this helps someone out there.