83 300 SD Fuel gauge dancing
 

I have a fuel gauge that bounces around as I drive around. From reading about the issue on the forum, it might be the fuel sending unit. How hard is it to get out, without the special size nut? I also have a fuel tank screen filter waiting to be replaced, just don't have the right tools to get it out. Any feedback is appreciated.

These fuel sending units get gunked up after years of diesel exposure.

There is a way to degunk things in your fuel system:
Biodiesel at least B20. Many folks start at B5 and work their way up.

Downside is that your fuel filters may clog as the system cleans itself out. Also, if you have any weak fuel hoses, they may fail.

Upside is your fuel gauge will likely begin to act better AND you'll have a clean system. Biodiesel is a better lubricant than Dino diesel.

Beware of using Biodiesel in the winter time because it's more likely to gel than dino diesel. If you live in the north, it might be better to wait until spring to try a biodiesel degunking.

Sender is easy to get out with a toilet wrench. Wide adjustable wrench available at your local hardware store for about $7. Use it straight on the nut and turn it with a long 3/8" extension thru the hole in the handle.

Thx for the info, I will try it out this weekend. It has gotten colder here, so I will wait till spring time with biodiesel recommendation. I have seen the closest gas station with biodiesel about 30 miles from my home, it is just not convenient. I have been adding small amounts of diesel kleen lately. The fuel prefilter is still clean. I did a purge about 3 weeks ago and replaced both fuel filters. The gauge is now dancing a lot less, due to valve adjustment and new engine mounts.