Fuel tank sending unit removal

[Mrbill426]

Can the sender be removed once the tank is installed?  Mine is all in but with probably 3/4 of a tank of fuel it reads about 1/4 on the gauge.  Everything is new and I tested everything on the bench before the install; grounding strap on the rear fuel line is "clean" and tight too.  I don't want to "disturb" the sealing if after remove the lock ring I can't get the sender out without lowering the tank.  It's a upper rearward side mounted sender is a '72 Cuda.

[7212Mopar]

Is the sender orientation correct? Float arm may be tangled up or float is leaking and sink to low level. I can remove sending unit without dropping tank on the Challenger. Not sure about Cuda location.

[Katfish]

I was able to remove and replace mine, 70 Challenger, but basically the same.

[anlauto]

There's other factors like exhaust and stuff, but yes it can be done

[Jay Bee]

Make sure you're below 1/2 tank just to be safe, otherwise you might be spilling some.

[Joegrapes]

I'm an expert at this 😂. I've removed and installed the sending unit dozens of time trying to get it to read right. You don't need to remove the tank but take the gas level down to less that half tank, 3/4 is to much. It will spill out of the sending unit hole so if you don't drain the tank put a large pan or something to catch the gas. You can't put the sending unit in wrong. There are notches in the tank and tabs on the unit so it will only go in one way. If you're using an aftermarket sending unit it will NEVER read right. It's not that the unit is defective it's that it's made perfectly wrong for our application. The only way I solved the reading issue is by installing an OEM unit. One more thing, if you still have the muffler heat shield there it will need to be removed first. I'm not using the shields anymore since I don't have the mufflers there so I just left them off.

[Mrbill426]

Thanks guys for all the information.  Everything is "fresh" back there so unless the screws holding the heat shields (I have mufflers) snap off in the frame rails I should be good to go after I drain the gas down to a safe level.  Yes the sender is aftermarket, Spectra I think, and might always be a bit off but I'm thinking not THAT much.  I honestly didn't know you can still buy one (OEM) from a dealership.
Maybe just orientation but it looked right to me when I put it in.

[Jay Bee]

I've done this a few times too, no mufflers there so it's pretty easy. For aftermarket Spectra is the best of the worse (IMHO). My Spectra sender is off by about 1/8, when my gauge is at 1/2 there's more like 5/8 in the tank. Maybe some day I'll adjust the float arm but for now it's close enough that it's liveable.