TR2/3/3A TR3 Gas Tank Grounding

[TR3-Stu]

On installing my refurbished TR3A gas tank, I put a thin rubber layer between the bottom of the tank and the tub body, as well as a thin strip between the tank hold-down straps and the tank. Now thinking back on it, I've isolated the tank from the body and therefore a ground. Should the fuel tank be grounded to the body?
My fuel sender is grounded to the body, but the tank is not.
Any thoughts would be appreciated.
Stu

 

[NutmegCT]

Hi Stu - Isn't the fuel tank grounded to your chassis by the metal fuel filler pipe?

 

[Frank Canale]

Hi Stu, If your sending unit is grounded to the chassis then I believe the tank is grounded via the sending unit mounting screws. I just tested the TR3A sending unit that I am going to use and the circular mounting plate is common to the grounding stud. I would do a continuity test on the tank as well as the sending unit and see if both are grounded. The sending unit gasket will isolate the tank and the sending unit but the mounting screws should still be a path for the tank to be grounded. Frank

 

[TR3-Stu]

Hi Stu, If your sending unit is grounded to the chassis then I believe the tank is grounded via the sending unit mounting screws. I just tested the TR3A sending unit that I am going to use and the circular mounting plate is common to the grounding stud. I would do a continuity test on the tank as well as the sending unit and see if both are grounded. The sending unit gasket will isolate the tank and the sending unit but the mounting screws should still be a path for the tank to be grounded. Frank

Thanks Frank - that makes perfect sense. I'll double check with a continuity tester as well.
Stu

 

[bobhustead]

Mac
The filler neck on the 3 is two pieces, one out of the tank and one from the cap assembly, connected by a rubber sleeve.
Bob

 

[TR3-Stu]

Hi Stu - Isn't the fuel tank grounded to your chassis by the metal fuel filler pipe?

On the TR3A, there is a rubber hose piece between the tank filler opening and the outside tank flip-up filler lid. I think I have my answer however in that the fuel sender unit is grounded to the chassis and the screws on the sending unit make contact with the tank.
Thanks, Stu

 

[sp53]

There is a ground wire also about 3 feet long that goes from the sender to one of the bolts that strap the tank down.

steve

 

[TR3-Stu]

There is a ground wire also about 3 feet long that goes from the sender to one of the bolts that strap the tank down.

steve

Thanks Steve. That's where my sender ground wire was attached, so I think I'm ok with the current setup.

 

[equiprx]

Add a braided ground strap.
It's cheap and easy and you can never be too grounded.

 

[TR3-Stu]

Add a braided ground strap.
It's cheap and easy and you can never be too grounded.

As my friends would say - because you own an old British sports car "you certainly aren't well grounded'. Just kidding - thanks for the tip, and based on my previous experiences with British cars (MGA, TR3, MGBGT) I know grounding is critical.
Stu