VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 37 coupe fuel sending unit

I'm assuming the only way to get to the fuel tank sending unit is either come in from the front by pulling the seat out... or climb into the trunk and pull up the cover board. Since I haven't yet removed the seat which I need to do anyway just to inspect and clean, I don't know if I can even access the tank from there. And the same goes for the trunk cover wood. Probably need to inspect under there also just for good measure. Besides, ya never know what you'll find under any of those locations. Has anyone else done this?

In the ‘37 coupe there should be round metal access cover (about 5” in diameter) near the front of the trunk. It is held down with wood screws. At least there was in my ‘37 coupe.

Great. I looked but obviously not close enough. I'll look again tomorrow. It'd be nice to have a working gauge. Don't want to shop for new unit until I can see what I have. Thanks

It should be the same as my 38. If so, Rusty is correct. Pics below. FYI, the tank comes out after removing the floor board in the trunk. I suppose you could pull the seat and mounting hardware to pull it from the front but it would be like pulling the engine to change the oil.

Tiny, you must be of farmer heritage. In your picture, I see a large and small hammer, a large screwdriver, and a pair of channel locks. The perfect set of tools to carry on a farm tractor back in my day. We also carried a Ford or 12" adjustable wrench.

I forget what I was using the hand sledge on. I was using the ball peen with the impact driver laying next to the screwdriver. Those machine screws hadn't moved since the car was new and had nature's locktite on them so persuasion was needed.

That is the same location as the fuel sender access cover in my ‘37.

There are 2 differences in Tiny’s picture to indicate that it is not a ‘37. The big difference is the style of the trunk lid support. Chevy went to the telescoping support in 1938. In 1937 is was a scissors type hinge that only locked in the full open position.

The other minor difference is the hole cut in the rear panel to allow access to the valve stem on the spare tire. There was a service bulletin in January 1937 that showed the dimensions to add this hole. The bulletin stated that there was no hole from the factory due to concern that smaller loose objects in the trunk could fall through it. So they either added it to 1938 production or someone added it to Tiny’s car.

Found the cover right there. Duh. Uncovered the sensor. Pulled it and checked it out. The resistance was off by two teeth...If that makes sense. We were able to pry the teeth up just enough to get the resistance range within some kind of tolerance. I'm thinking like 4-30 something ohms. Kinda figured we were going to replace it anyway so what the heck if we broke it. Reinstalled it and now we wait. It's got maybe 10 gallons in it and it definitely doesn't show a half tank. The Filling Station has a replacement so once I get it legal (haven't even transferred the title yet) I'll fill the tank and see what it shows. Not really expecting much but at least I have a plan now. Oh, and my trunk is definitely the 37 version I.e., no hole in the wood. Funny that my 37 Buick DOES have the hole. Must've been a big deal that the Buick got it a year before the lowly Chevrolet. Go figure. Nothing has changed.

Oh, and MY 37 trunk support is telescoping... as is the Buick's.

Not sure I understand the “off by 2 teeth” but if it works like you think it should leave it alone. You might need to bend the float arm to “calibrate” the gauge.

The 4 to 30 ohm range is pretty close. Normally they range from 0 to 30. A simple test is to remove the sender from the tank. Connect the wire from the gauge to the terminal and connect a ground wire to the sender body. With the ignition on you should be able to see the gas gauge move through the full range as you move the float arm.

If your car was built as a late ‘37 model that could explain the telescoping supports. During a model year changeover new parts might be introduced early rather than order another batch of the old style. Or those could have been installed as service part replacements. The later Master Parts list show that substitution along with a note about drilling extra holes.

I believe he's referring to the gear teeth that allows the float to transfer vertical movement into rotational movement. This is my spare sender. I found changing it by one tooth made it more accurate.