Just got a new fuel gauge sending unit for 48 DeSoto

[MarcDeSoto]

I assume that this sending unit is installed with the float slanting toward the front of the car.  Mine has two wire terminals to the top of the unit.   I was surprised to learn that in the new 49 model Mopar cars changed to a new type of sending unit with just one wire.  The two wire sending units are called the thermostatic type, and the one wire units are called the electrostatic sending units.  So I guess the 46-48 models were the last cars to have the thermostatic sending units.  No directions came with my unit so I assume that the float is installed to slant toward the front of the car.  There is a good booklet on all of a car's gauges in the MTSC booklet Gauges from 1950.  The filmstrip is missing so I will try to contact MyMopar to see if they want to borrow my filmstrip and/or record to put online.  https://mymopar.com/mtsc-1949-volume-2-6-transmission-fundamentals/

[desoto1939]

Mark: the top unit has five holes in the body of the flange these will align up with the holes onthe top of the tank. these holes determine the direction inwhich the the float and arm will be when installed. do not try to force the unit to have the float facing forward. Also recommend that you run a ground wire.

 

Rich Hartung 

[Sam Buchanan]

It will only install one way due to the spacing of the holes.

[MarcDeSoto]

I wish they would include the screws with these sending units.  I can't find the #8 32 X 3/8 screws anywhere.  I found this size but it was a machine bolt with nuts.  Those can't screw in unless you are lucky.  I bought a #8 X 3/8 sheet metal screw, but that won't work because it has coarse thread.  

[Los_Control]

I can only imagine that different tank manufactures use different threads .... metric, SAE, course or fine ..... no screws provided makes it more universal.

[DJ194950]

Ya got a Home Depot in your neighbor hood?

 

46 minutes ago, MarcDeSoto said:

I wish they would include the screws with these sending units.  I can't find the #8 32 X 3/8 screws anywhere.  I found this size but it was a machine bolt with nuts.  Those can't screw in unless you are lucky.  I bought a #8 X 3/8 sheet metal screw, but that won't work because it has coarse thread.  

https://www.homedepot.com/p/8-32-x-3-8-in-Phillips-Oval-Stainless-Steel-Machine-Screw-4-Pack-801781/204282627

[MarcDeSoto]

Already been there and done that.  Those don't screw in because you need a screw that comes to a point because the holes are kind of jagged.  I did get one of those machines screws in, so maybe I could tap the other holes and use them?  

[MarcDeSoto]

Found out they don't make sheet metal screws with fine thread, so I went back to HD to buy #8 32 1/2" round head screws.  The Parts List calls for 3/8" screws, but these newly made sender units are about 1/16" thicker than the original.  I had to tap the threads in the tank to get all of the screws to go in, but they finally did, so the installation was successful.