I am trying to fix the float in my gas tank, but I heard it was advised to replace the O-ring gasket that sits between the tank and that locking ring. I checked if Napa near my house has it, but they don't have anything for my 1991 cherokee, but they have a bunch of generic o-rings of different sizes. Does anyone know the dimensions of the ring?

 

There are none listed in the parts catalog but think the part number is 53000575.
I think this will give you what you need plus a new lock ring also.

https://shop.advanceautoparts.com/p/...tank+lock+ring

 

By googling the part number, I found different dimensions, but the most common one was 3.75 inches and the rubber part is 0.25 of an inch. Does that seem right?

 

Found it with the fuel pump. That's the correct number for the seal.

https://www.moparpartsgiant.com/part...ding_unit.html

 

Should have been clearer.
Meant there were no specs for the O-Ring. LOL.

 

Ah, went back and re-read it. You were clear enough.

 

See now that is funny.
Cause after I read your post I reread mine and I didn't think I was. LOL.

 

Measured it, and the dimensions are 3 inches inner diameter, 3.5 inches outer diameter, and 1/4 inch thickness. I found this on amazon which should hopefully fit