Has any one had good or bad experience with a 3:1 differential? Considering a car with this set up but have not had an opportunity to drive it. Is the increase in speed worth the loss of torque? I live in a very flat area. Any input? Thanks. John
The loss of torque is also the loss of braking power if you don't have aux. brakes
In a light car with out too much wind resistance in your area should be fine
Car has Rockies.
I wish we had 3:1 gears in our 13. The engine always has been strong, and with a high compression head and Stipe cam, it would benefit from a higher ratio. We also have aux brakes, and of course, Nebraska is flat (but windy).
Thanks all. Trying to decide but wife is pushing me toward a Model A. Prettier, she says. At our weekly breakfast last Sat. there were seven A's and not one T. Before I sold my old home made truck at least there was one driven regularly around here. The car I'm considering is a 25 touring, black of course, and not as aesthetically appealing to the fair sex as the A in green and black with ivory wires. In addition it's a sedan which she says she would feel safer in. It's a conundrum.
It's not a conundrum at all. Your wife wants an A, you get an A. Few enough guys have wives who take an interest in ANY old car!
We have broken 3 standard T crankshafts, one in my roadster pickup, a second in my lightweight speedster and the third in my 1917 shooting brake. The common denominator in all three was a 3:1 diff ratio. That, and the severely compromised braking, makes me never to want to go down that route again.
FWIW Allan from down under.
I bought a touring 9 years ago with unknown mileage on the somewhat tired engine. The car is outfitted with a rucks tell and 3:1 gears. I have put a lot of hard miles on it in the last 9 years with no problems. It is slower than other cars on some hills, and faster than other cars on the flats. Where a 3:63 car seems comfortable cruising between 30-35, a 3:1 likes 35-40. I have toured with Model A's in hilly terrain and found that my T in Ford high-Ruckstell low would gain ground on the A's on hills and I often had to slow down behind them.
Gee, am I lucky, Allen, my Dad and I committed the "Cardinal Sin" in the 1960's when we restored my Grandfather's 27 coupe. Everything that I've heard on the Forum since joining decades ago, was, "Don't install a 3 to 1 gear set in a 26-27 enclosed car because their heavy weight is too much for the gearing. Well, not knowing any better at the time, I talked my Dad into the idea. The car originally had a 4 to 1 gear set. Well, the gears have outlasted the engine (and it isn't really trash; just a crack in a water jacket. I am presently replacing the original rear axle with a Ruxtell, also with 3 to 1 gears. I don't live or drive in hills or mountains. The car will have rear brakes this time around. With the original rear end, the rear brake parts weren't even installed. the transmission brake was all we had.
I have found that a 12 tooth pinion with a 39 or 40 tooth ring gear (3.25-3.33 ratio) is ideal with a Ruckstell. Going to give an 11-39 (3.54) gearset in a 6 rivet rear end on a 1911 Runabout a go here soon, and see how that works without a Ruxtell. Best, Jeff
I would (and do) only use 3:1 gears with a Ruckstell or other underdrive.
I have 3:1 gears in my '15 runabout with Ruckstell with Reeder head and Chaffins Touring cam. I like it.
I have 3:1 in my 1919 touring with Ruckstell, Z head and Chaffin's touring cam. The 3:1 is just a little too tall for a loaded touring car. I have a 12 tooth pinion (Thanks, Terry )and will one day put it in the touring car for the 3.25:1 set up.
: ^ )
All three of mine had auxiliary transmissions/Ruckstel rear axles. My theory is the 3:1 rear end encourages the driver to lug the engine over rises/into headwinds. I know I did in the shooting brake.
I now have the 39 tooth ring gear in the Ruckstel, mated to a 12 tooth pinion, for my new roadster. 3.25:1 I hope will be a better compromise.
Allan from down under.
I recently pulled an old stock 3-1 set out of my '13 roadster, and a few weeks ago, I bought a '17 coupelet, and it has them too! I like stock.
I have 3 T's. All have standard engines with standard heads. Two have standard Ford ratio with Ruckstell. The other has 3:1 ratio with Ruckstell. I live in Southern California with traffic and many hills. The 26 Roadster is the fastest of my cars. It is light weight and will pull many hills in high. On one tour we went from Kanab Ut to Brice Canyon. I went all the way in high. My second car is a 26 Touring. It has the same type engine and same gear ratio as the Roadster and not quite as much pull on hills. I believe it is because of the weight. It also has bumpers. I can tell the difference in the performance according to how many passengers I have in it. The third car is a 22 Roadster. It goes much smoother with slower engine speed on level or downhill, but I need to downshift to Ruckstell when I start out from a stop if there is the slightest grade. On tours going uphill, if I can keep it going between 25 and 30, it will climb a 6% grade in high. But on the tours, most of the cars go about 22 to 25 in high up the hill so I need to shift to Ruckstell to pull a hill my other T's will easily pull in high.
Anyway, I guess it depends on which car you have and where you drive it. Around here there are a lot of signals and stop signs. So I have to use
Ruckstell quite often.
I wouldn't recommend that ratio for a touring or a sedan. Only a Roadster.
My earlier comment was about 3 to 1 gears in a stock T.
I have a depot hack with a Ruckstell and 3 to 1 gears. The car has Rockies, Z head, Hi flow intake, straight thru carb., freer flowing exhaust and light flywheel.
It's a nice driving peppy vehicle.