Topic: 1940 ford rearend ratio


jf    -- 08-14-2011 @ 9:30 AM
  Hello, Could the ratio be identified by the stamped #'s
409 on the bottom webbing of the rearend housing.I maintain 60-65 mph and the replacement 59AB motor sounds good not screeming as others expect.



kubes40    -- 08-14-2011 @ 9:52 AM
  I've never heard of 409 on the pinion gear housing. Are you 100% certain you are reading it correctly?


supereal    -- 08-14-2011 @ 10:22 AM
  Me neither, Mike. The numbers for the 4-55 gears are 419, but the engine would be screaming at 60 with those. The stamps on the web of the banjo are not always true because the gear set could have been changed. The ratios and stamped numbers are: 4-11, 379, 3-78, 349, 3-54, 3911, and 4-55, 419.


ford38v8    -- 08-14-2011 @ 12:27 PM
  You guys never heard of a 4.44?

Alan


jf    -- 08-14-2011 @ 1:46 PM
  Supereal, Thanks for the numbers and like Mike asked about being certain, I'll check my numbers again.Can I physically check my ratio by jacking up rear wheels,with trani in 3rd,spark plugs removed and rotate rear wheel one full rotation and count motor rotations at the crankshaft at the same time with a second person. Joe


supereal    -- 08-14-2011 @ 2:09 PM
  Of course you can do that. It is just that the ratios are fairly close together, so it can be tough to get them right. And, yes, Alan! I've heard of 4.44 , but he says he can run 60-65 without the engine screaming, which would certainly be the case with that ratio.


ford38v8    -- 08-14-2011 @ 3:11 PM
  Bob, I had a 4.44 in my rear when aI bought the car. On tours with my RG, I'd keep up with the pack, and the leader would go 60+ all the time. This confirmed by my speedo and by several others, including the leader. The kicker, I think, is that my engine is a 59L, with lower compression and milder cam than a passenger car engine.

JF, your number does indicate a 4.44x1 ratio, but that's really not a gaurantee of what you actually have, as the ring/pinion may have been changed out at some point.

Your question of how to check the actual ratio will work. You'll need two helpers to do this: One at the rear wheel to count, and on e at the engine to count. Mark one blade of the fan with bright tape, and also one spot on the tire. Leave one tire on the ground and raise the other with a jack stand safely on the axle housing. Count exactly twenty wheel revolutions, and note the exact position of the fan blade mark. You will have one of the ratios mentioned earlier: 4.44 ((44.4 revs); 4.11, (41.1 revs); 3.78, (37.8 revs); or 3.54, (35.4 revs).
Note: Try to do this in one pass, as the clutch may slip a small amouint each time you start & stop. Also, if you choose to do it with both wheels up, the number of revolutions for the wheel will be 10, not 20.

Alan


trjford8    -- 08-14-2011 @ 8:34 PM
  4.44's were used in the 60 hp cars. I've had two sets of those gears. If you are running 60-65 mph and the motor is not screaming at you then I suspect that the gears were changed in that housing.


ford38v8    -- 08-14-2011 @ 10:57 PM
  Tom, yes, it was screaming. I changed out my banjo to a 3.78, and Cal Sato bought my 4.44's. It wasn't till a few years later when I dropped an axle that I discovered I had '39 axles. The whole assembly must have come from a 1939 60 hp car.

Alan

Alan


trjford8    -- 08-15-2011 @ 8:12 PM
  I should also note that the 4.44 were also used in the 4 cylinder 40-41 pickups.


janine    -- 08-18-2011 @ 2:34 PM
  I have that same stamp on my rear end ( S ) what does the letter s mean


Stroker    -- 09-03-2011 @ 3:02 PM
  Janine:

I wish someone would solve the mysterious "S" question. I have a number of banjo housings,
all displaying their originally installed gearset ratios stamped. I may be becoming blind, as my Wal-Mart reading glasses are now at 175, but I have yet to see an "S".


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