fuel gauge not reading accurate

[350dieselsmk]

Hey guys,
borrowing my friends 2003 6.0 this week while my 7.3 is in the shop. since he got it the fuel gauge has not read correctly. its all over the place.. when i just wet to get the truck it was reading empty and the fuel light was on when i pulled into the diesel station it was reading a quarter tank and after i put a couple gallons of fuel in it was back down to an 1/8th of a tank. any idea what is causing this?
thanks
Will

[F250SixOH]

My fuel sending unit is junk too. I just keep an eye on my mileage since a new sending unit is ridiculously expensive. I usually just reset my trip odometer every fill up and go 300-350 miles then fill it back up. Sucks because I have to always bite the bullet and fill her up

[350dieselsmk]

yeah i hear ya damn 6.0s haha