1941 Transmission Gearset Tricks?

[Fred A]

I have a 1941 convertible. Ford advertising describes the 1941 cars to be faster than pervious models. Same engine, heavier car, nonsense. Does this magic trick may reflect some change in gear ratios that allows some narrowly supported claim. I'd bet on a 15/29 gear as standard. Good Luck: Fred A

[petehoovie]

Originally Posted by Fred A

I have a 1941 convertible. Ford advertising describes the 1941 cars to be faster than pervious models. Same engine, heavier car, nonsense. Does this magic trick may reflect some change in gear ratios that allows some narrowly supported claim. I'd bet on a 15/29 gear as standard. Good Luck: Fred A

[38 coupe]

The only way the advertised statement "now geared to give even faster getaway through "first" and "second" with no sacrifice in "top" performance" makes sense in a heavier car is to use a lower gear ratio in first and second. Ford already had the gear set in common use on the Mercuries with the 3.54 ratio rear axles so it would have been a parts bin swap.

[cadillac512]

My '41 Merc had a 15/29 gearset and 3.54 in the diff. When I rebuilt the trans I went with 16/28 and it's much better especially with the stronger 260" 8CM in it now.The magic is all about the advertising...

[Tim Ayers]

No sacrifice to top performance is certainly true since all 3rd gears are 1:1 ratio. LOL!!!!

[V8COOPMAN]

Sponsored Links (Register now to hide all advertisements)

.

Anyone remember a short-lived Ford Pick-up Truck ad on TV which was worded almost verbatim:


"Ford's Larger Fuel Tank So You Can Go Farther For Less"


Coop


.

[fortyonerag]

Wait, what, the 41 supposed to be faster than the 40 !!!???

Who knew?

[Seth Swoboda]

I don't know anything about the claims in Ford's advertising, however you can do a lot with gearing. I install a 3.54 gear and 29/15 tooth cluster in all my V8 projects now. This fall I installed a 3.25 rearend and 29/15 tooth cluster in a '37 Tudor. I'm not winning any races off the line but the cruising speed and RPM's are amazing. 75 mph in that '37 if you want too with ease.

[Fred A]

Seth, that's good news, as I need more top speed for survival on the Freeways. I have a 59A pushing those gears in a 40 that may make noise in '24. Ideal is a 99A in 01A dress. Too many projects. Good Luck: Fred A

[Seth Swoboda]

Originally Posted by Fred A

Seth, that's good news, as I need more top speed for survival on the Freeways. I have a 59A pushing those gears in a 40 that may make noise in '24. Ideal is a 99A in 01A dress. Too many projects. Good Luck: Fred A

If you have a light(er) car and a 59A engine, a 3.25 gear set will make it a rocket ship.

[Pete]

One big thing to remember, of the 4 popular gear sets for that transmission, the 29'a are the weakest.

[Seth Swoboda]

Originally Posted by Pete

One big thing to remember, of the 4 popular gear sets for that transmission, the 29'a are the weakest.

Out of curiosity what makes the 29 tooth cluster weaker? I'm running them behind stock engines. Two, 221 engines and a 59A.

[Will Kimble]

I have never heard - or observed - the 15/29 set to be weaker, so I am curious to hear as well.

[Pete]

Originally Posted by Seth Swoboda

Out of curiosity what makes the 29 tooth cluster weaker? I'm running them behind stock engines. Two, 221 engines and a 59A.

They have the most torque multiplication so have the most stress.
They are fine and will last almost forever with low hp applications.
They won't last one run with a big engine.
They are poor for racing anyway due to the wide ratio splits.

[Seth Swoboda]

Originally Posted by Pete

They have the most torque multiplication so have the most stress.
They are fine and will last almost forever with low hp applications.
They won't last one run with a big engine.
They are poor for racing anyway due to the wide ratio splits.

Thanks for the information. I'm all street, daily driver application. Stock engines , low horse power. Slow and steady is my credo.

[V8COOPMAN]

Originally Posted by Pete

They have the most torque multiplication so have the most stress.
They are fine and will last almost forever with low hp applications.
They won't last one run with a big engine.
They are poor for racing anyway due to the wide ratio splits.

Pete is correct! The same is true for most all gearsets as the 1st GEAR ratio rises NUMERICALLY. Most old Ford V8 transmissions use the 28-tooth cluster which equates to a 2.82 1st gear. The 29-tooth cluster (if I remember correctly) equates to a 3.15 1st gear ratio, NUMERICALLY higher than the 2.82. When you begin INCREASING the torque multiplication between two gears like that, you increase the stress of those two gears trying to push themselves apart from each other in the transmission case. Hence, the torque rating goes down, which equals WEAKER!

Believe me, the more you begin to understand about transmission ratios (as well as combining those ratios with REAR end ratios), it will open-up and enlighten a whole new world for your motoring enjoyment (and success).

Coop


.

[Seth Swoboda]

I've seemed to enjoy the 29/15 and 3.54 rearend combo for years. I decided to try a 29/15 and 3.25 behind a little 221 engine to experiment. It's a fresh engine so it does fine. Not going to the races but gives me a great 60 mph driving experience. So far....

[V8COOPMAN]

Originally Posted by Seth Swoboda

I've seemed to enjoy the 29/15 and 3.54 rearend combo for years. I decided to try a 29/15 and 3.25 behind a little 221 engine to experiment. It's a fresh engine so it does fine. Not going to the races but gives me a great 60 mph driving experience. So far....

Seth ...... It's obvious that your rear tire diameter is not too large to deter from a workable combo. And the weight of your '37 is low enough such that your fresh engine is more than capable of spinning with the program in your case. You're still on the POSITIVE side of the equation with all of the parts choices you have made.

If you were (for instance) to change to a 3.00 rear end, or increase your rear tire diameter, you MAY be getting into "iffy" territory where the engine was no longer capable of pulling hard enough in 3rd gear to maintain or increase speed. You seem to have hit on a 'happy' combination.

Coop


.

[Seth Swoboda]

Originally Posted by V8COOPMAN

Seth ...... It's obvious that your rear tire diameter is not too large to deter from a workable combo. And the weight of your '37 is low enough such that your fresh engine is more than capable of spinning with the program in your case. You're still on the POSITIVE side of the equation with all of the parts choices you have made.

If you were (for instance) to change to a 3.00 rear end, or increase your rear tire diameter, you MAY be getting into "iffy" territory where the engine was no longer capable of pulling hard enough in 3rd gear to maintain or increase speed. You seem to have hit on a 'happy' combination.

Coop


.

6.00 x16's. I'm pretty boring in that regard....