Can I replace fuel sender unit without removing fuel tank?

[Dans 68]

As I need to calibrate and probably replace the original fuel sender unit, and as I'm always looking for an easier/cleaner/more logical way on doing anything ( ) is it possible to change it out without taking the fuel tank out first? The FSM directs me to remove the fuel tank before removing the sender unit. So for all of you that have done this...how have you done it? I've read the threads on calibration after you get the unit out, on setting the half full measurement, etc., so that is covered. Ideally I would run the tank dry, fill it up with 10-gallons, and install/calibrate the sender unit. Thank you for all your opinions.

Dan

[Hemidog]

Yep, I've done it.
Filled the tank with 10 gallons and took it out (Many times!  )
Didn't even jack the car up.

My gauge now reads correctly on the Empty side, but goes way over Full when the tank is full, but the Empty side is what matters.

[Dans 68]

Thanks, Hemidog. Good to know. I guess I'll get to work this weekend on it! 

Dan

[Nacho-RT74]

it is posible on 3rd gens at least... same, doen't even need to jack up the car if you have the stock ride height

[tan top]

it is posible on 3rd gens at least... same, doen't even need to jack up the car if you have the stock ride height

yeah don't even need to on a second generation  ! well i could get under there 20 years ago  ! but too many big MC meals have happened since 

[bill440rt]

I have to jack up the car on all 4 corners to get it level. Let the rear axle hang to give you some more room. I loosen the straps at the J-bolts to drop it down for better access.
Either syphon the gas out or let it run until empty. I put in 5 gallons to give 1/4 tank. Then, I remove the sending unit & hold it in place the same way it would be installed in the tank. Have a helper watch the fuel gauge, & move the float as the other person watches the gauge. I then tweak the float arm until it reads correctly.
Install it in the tank, & check. Remove & re-tweak as necessary. Then, I add another 5 gallons to give it about 1/2 tank, & check the fuel gauge again.
Kind of an "eyeball" way of doing it, but I got my '68 to read very close this way. I have to do the same thing to the '69 now. 

[Back N Black]

I had to adjust mine last week.  I drained the tank and put in 5 gallons and use a voltmeter to measure voltage at the sending unit, then i pulled the sending unit and hooked it up on the floor using a couple of jumper wires, i measured the voltage again and moved the arm to read the same voltage i had when it was in the tank. I marked the position of the float on the floor and then moved the sending unit to measure 1/4 tank on the gauge. Next step was to bend the arm back to the first mark on the floor.It took all the guess work out of the process.

[Dans 68]

To add more content to this thread, what brand sending unit do you recommend? What have you used? Three I've found vary in price for a 3/8" fuel sender unit:

Megaparts: http://www.megapartsusa.com/proddetail.asp?prod=183-U114

YearOne: http://www.yearone.com/serverfiles/fbshopmain2.asp?hid=114GW16125

Dante's: http://www.dantesparts.com/fuelsending.html

Thanks!

Dan

[70sixpkrt]

I talked to a buddy of mine who owns an auto parts place and he says they are all pretty much made in China these days. One of these days I need to pull mine out and calibrate it. I changed it 15 yrs. ago and never calibrated it. I fill it up and it shows 1/2 tank on the gauge.

[Dans 68]

It looks like YearOne and MegaParts senders are the same (except YearOne charges $79 more   ). The RockAuto item (SPECTRA PREMIUM Part # FG68B) looks a bit different (plastic float?).

Dan

[Rolling_Thunder]

So is there any sending units out there that actually read accurately with the correct resistance values ?

[Nacho-RT74]

the one I got was Plug and Play, it was the CHEAPER on the market and also the correct look with brass floater and metallic strip ( except for the straight outled what should be 45º ):

prices haven't changed a lot since those days, from VANS:

http://cgi.ebay.com/ebaymotors/Mopar-68-69-70-Charger-gas-fuel-sending-unit-3-8-NEW_W0QQitemZ170293766478QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item27a64ca94e

Only detail is I have lost the reading maybe 3 or 4 times after a big BUMP... but then kick out the gas tank and VOILA! LOL. mostly sure will need to remove and apply some light pressure on point tab against rheostat. piece of cake