VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 31 gas tank

I'm in the process of reinstalling the stock tank back in the car with the stock mounting straps. The top of the gas neck sticks up above the apron about 1/4".
With nut and washer on the end of the strap there's about 3/16 " above the nut. I get the feeling the tank should be further up into the void that cradles
the tank ? the upper part of the tank in front is very close to making contact with the cradle and I have about 1/2" space from the rear surface of the tank to
the lip on the cradle or frame.

Comments and advice is always appreciated

thanks !

Hello lynda,
I have a 31 but have never removed the tank as yet. I don't have access to measure now but I'll try to find out soon how much the neck is above the apron. With regards to the 1/4" neck above the apron measurement, I wonder if the gas cap can be installed or removed normally. Is it possible to use a jack to raise the tank until there are no voids front to back or side to side? Was there any changes to the gas tank to cause it to have a different shape? If there were any rubber shims or pads associated with the tank I do not know. What I do know is that it is not correct to mount a tank that is not secure in all ways.

Thanks for the response Harry. We used a jack to get the tank in place and we should have checked the gaps front and rear before removing it.
The cap will go on but it seems like the filler neck should be a bit higher than it is. It seems like the 1/2" gap at the rear should be 1/4" and that would
get the front clear by about the same. The difficulty is getting the tank up any higher than it is. If the car were on a lift it would be a lot easier to see
whats going on. The straps are also real buggers to keep in place while raising the tank up.

I checked the measurement on my 31 Sport Coupe yesterday afternoon. The top of the tank neck was exactly 1/2 inch all around from the raised apron portion that it goes through. The tank was removed for cleaning several years ago and I reinstalled it without any specific regard to this measurement.

This sounds like a replacement tank that is not exactly the same size as an original. As long as you can get the gas cap on securely, the neck is high enough. Mine is a replacement tank and the neck is between 1/4" and 1/2" above the apron. For the straps, I installed them without lock washers and tightened them securely. Then, one at a time I took the nut off and installed a lock washer. Doing it that way makes it much easier to start a nut and get sufficient length for the lock washer.

I never needed a jack to install or remove the tank although I suppose that might make it a bit easier.

I hope that you added a ground wire from the gauge to the frame. If you didn't, you'll likely need to drop the tank to add one so that the gauge reads correctly.

Hello lynda,
As gachap did, I just measured the uncapped gas tank fill neck above the apron on the 31 Coach. 1/2" above the raised apron surround. Just enough to get a good grip on the cap when installed.

UPDATE: the tank is in and we have close to 1/2 " of the gas neck above the apron. This is the stock tank which we had sealed years ago and the mounting straps are the originals.
We purchased a gas neck grommet from I&I which we installed onto the apron before putting the tank in place. There's a hole in the frame directly in front of the sending unit which
we used to run the sender wire and ground wire through.

All is well......

Thank you all for your input, we appreciate it very much !