Fuel tank sending unit

[Charlie ny]

I'm attempting to get my gas gage reading somewhere near correct.
I purchased a Bob Drake gas tank and sending unit for my '41 1/2 ton.
The truck is now 12volts neg ground and the stock gages are reduced
to 6volts. I have shortened the arm on the sending unit per the instructions.
My dilemma is the gage reads way over full until the arm is 3/4 down.
I called Drake and was told if the arm is shortened per the instructions
everything will work "perfect'. To be absolutely sure I wasn't dreaming
I removed the sending unit and with it wired up I moved the arm and
watched the reading on the gage....same readings as when it was in the
tank. The arm is shortened correctly and Drake says in the catalog the
sender doesn't care whether it's 6 or 12v.
The old beat up sender reads much closer and the dash gage is NOS.
Any ideas out there? Further input from the great northwest would be
appreciated too.
Charlie ny

[Kube]

I have had the same experience as have two of my friends. Total junk.

[Ken Crans]

I had the same problem... I had to find the right sending unit, Drakes is bend to suit. Sacremento had the correct short arm. I'm assuming you have the stock tank? if it's poly then all they have is the custom sending unit which is 6 or 12 volts. Make sure your sending unit is fully grounded. Run a wire straight to the frame. You will have to experiment bending the float arm with the correct unit to get it just right. Ken

[Adam/Mill Valley CA]

I had the same problem using a modern sender for my '36. I put a small resistance (I think it was about 10 ohms, IIRC) in series with the line to the dash gauge and it brought the reading with a full tank down to just above the F mark, then bent the arm a bit -works reasonably well now.

Adam

[al pa.]

I also have the Drake sender,it's not installed,but I checked the resistance against a stock 6 volt sender,and the readings are not in the same range.I'm afraid to use it,when I'll probably not have any success with it.

[Charlie ny]

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Thanks everyone...this what I thought it would boil down to. I will keep the
balance of my thoughts inside for now and wait for Bob Drake to reply. Ryan,
if at all possible keep this thread "up there" at least for a day so Bob can see
it.
Charlie ny
[email protected]
Drake cust # 9810

[RMR&C]

I bought one a while back for my F-1 from vintique, whatever that is. Total junk....found an old crusty original and cleaned it up, works great!

[31chevy]

I purchased a universal sending unit from JC Whitney & used it on a universal guage as well as a Cyberdyne digital guage, this was not on my flathead however. There are 4 different resistance sending units that I know of maybe more. Ford/ Chrysler 73-10 ohm, Gm 0-90, Vdo 10-180, Universal/ Stewart warner 240-33 ohm. These are empty to full settings. Hope this helps.

[Brendan]

i just get gas every 100 miles LOL

[JM 35 Sedan]

Right on Brendan, when you have an early Ford with the red liquid in a glass tube type gas gauge, that usually don't work well anyway, you learn to mentally keep track of your mileage and estimate gas consumption. I fill up about every 100 miles regardless.

[Jack 34pu]

I guess we depend too much on the high tech solutions. The Model A group has it a lot easier when their gages don't work. My grandad used the same method on his tractors. It's called the yardstick method. Every hardware store back then gave away yardsticks with advertizing on them. My grandad had about a 2 foot piece with a wire on it to hang it on the tractor. Whenever he wanted to know how much gas was in the tank, he stuck the piece of yardstick in the tank - pulled it out and checked how high the wet mark went.

Sorry - just had to poke fun, but it is a true story. I've seen it done on Model A's also

[BILLF/TRF]

I have had problems with the Bob Drake unit as well. I followed Drake's instructions, couldn't get it too read correctly, then sent the Drake unit along with my '36 guage to Williamsons Instruments. They had trouble getting it adjusted and when I got it back, I filled the tank and while driving I noticed the needle stayed on full for a long time but when it moved it went down fast! The needle would then stay on 1/4 tank reading until I got too nervous and filled the tank again. I guess I can live with that.

[Ken Arms]

My 07 pickup stays on full a long time, then drops like lead!

[rotorwrench]

The Ford type (probably King Seely) were not designed to work on a set linear resistance since they use the heated bi-metalic strip set up. I know that the indicator unit will respond to a resistance type sender but you can never get accuracy through out the whole range. The cap will pull off the old sender units and you can see the heater strip and a wound wire resistance spool that was originally used to adjust each unit into the accurate working range just prior to final assembly. The old units can many times be repaired if you can fabricate or replace the defective part of the works.

Kerby

[Bruce in southern OH]

Charlie, I have my tank off of my truck right now, 41 1/2 pickup, are we saying that we/I should get a sending unit from (Sacremento had the correct short arm.) as per one of the post????
I had to purchase my new tank from Macs, it was in a Bob Drake box, and I purchased a new sending unit because it said it would not work with old stock unit, ( my old sending unit is very rusty ) and did not work before removal, my gauge does work. thanks for this post let me know what everyone says to do, thanks Bruce

[Lawson Cox]

I hate to jump in here, but I will, thinking that Bob may jump on my Axx again for criticizing his products. I have his tank and sending unit. Tank works okay but is on the flimsy side. The sending unit is crap. The float came off and still floating around in the tank. I am using another sending unit that I finally got to work, sort of. Stays full for long time then drops like a rock. So much for most of the repo crap nowadays. Sorry Bob, but 14 out of 15 are with me.

[Charlie ny]

Brothers,
Here's where I am at with the sending unit. Drake will not at this time
refund my $$$$$ in part because I purchased the sender and $1300 plus other parts
last Sept. AND because the part was altered. The alteration was per Drakes in-
structions but what the heck it's only money. I discussed this situation with Pete
Mostowa at Drake and he was ,to say the least extremely professional, I guess he
sort of felt my pain. I am going to send the sender back to Drake for evaluation
with no promises to me what so ever. Pete tells me this is the first time he has
been made aware of this situation....Pete also informed me he will follow up on
this matter personally with Drakes R & D.
The fact that all here have had the same problem bolsters my case
tremendously. I am now under the impression that this sender is made by some
outfit somewhere and marketed by all the usual vendors.
As a supplier and rebuilder myself I depend on the understanding of
my customers when something I've supplied for any reason disappoints. My first
inclination is to assume I have dropped the ball and not given full value....it
happens.
I will not let this matter rest until it is resolved.....hopefully long before
my visit to Bob Drake at Hershey this fall.
In the meanwhile I'm using a beat up sender from my old '37 sedan.
Charlie ny

[c-gor]

Charlie: If the sender is the typical Stewart Warner that is sold by most suppliers, it is very difficult to have it read correctly. Carpenter, DraKE, Mac's all sell the same unit.

I had one and I was able to have it read "F" and "E" correctly, but the in-between readings were never linear. I finally gave up, found a Ford unit and used it.

Good Luck

[itstom]

If this has a plastic float, quit wasting your time. In a month the ethanol will have destroyed the float anyway. I very carefully removed the crimped on top of my original and pulled a thin strip of paper through the points until the paper came out white. Working better than the POS new one ever did.

Be careful! There are some very thin wires in there.

Tom

[40cpe]

I recently went through this with AutoMeter. This is the tech response. I must say the tech line is very responsive although his answer isn't what I wanted to hear.

"You have a classic, common symptom of an after market, incorrectly manufactured sender, with a gauge calibrated for a factory, non-linear range.
The Auto Meter (and factory Ford) gauge is calibrated for:
Full: 10ohms
Half Tank: 25ohms
Empty: 50ohms
Pointer Width Below E: 73ohms

Your newer, after market sender is incorrectly calibrated as:
Full: 10ohms
Half Tank: 41ohms
Empty: 73ohms

The factory sender & gauge are non-linear. The after market “assumed” linear which is incorrect.

Also, grounding the sender wire for the gauge as a test will not damage the gauge. You should certainly see it go past Full when doing that.


Thank you
Cory
Tech/Service