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Hi guys. I thinking about adding an Auxiliary transmission to the Model t we're rebuilding. I was trying to compare them based on gear ratios because I also have the option of using an old 37 hudson transmission instead. Looking to get all the information before things get cut.

I've got the gear ratios for a Warford and the Hudson. What I'm missing are the ratios for the Chicago Mark-e, and the Jumbo Giant. I know some of this info is the old sales fliers. I don't have to have copies of the flies just the information.

Thanks,

Bruce

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Here is a good article by Murray Fahnestock with lots of gear ratios mentioned in the text:

http://www.nwvs.org/Technical/MTFCA/Articles/1803ExtraTransmissions.pdf

The sales material I've seen rarely mentions ratios, though sometimes there are claims like 60% more power with the Ruckstell = 1.6:1 gear ratio and 100% more power with the Jumbo Planator = 2:1 ratio.

I have another question when choosing what auxilary tranmission to use on a light speedster - how much do the popular alternatives weigh?

Some of the contributors here may have shipped a Ruckstell or the different versions of Warfords & thus remembers approximate weights?

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Roger, Thanks for posting this great article.

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Another problem is that one manufacturer often had several different ratios. I know of 3 different Muncie ratios and I believe Warford had several also. All of them are very, very, wide because they were mostly used in TTs. Usually about 0.72 overdrive, which gives 2.6 final drive for a standard rear. The low is usually something like 1.9 or 2.0. I went with a 4:1 rear in my Muncie in order to get a 2.9 final drive. Those two gears are very nice, but then low is too low to be very useful at 7:1

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Send me your teeth counts! I'd like to do a webpage on this subject. I think it would be a valuable addition to the hobby. I've already got the Ruckstell, Muncie and some of the Warford ratios. If I can get people to post what they've got or email me, I will accumulate the results and put them at the Tulsa website. If you don't want to calculate the ratios, just count the teeth and I'll do it.

The page on heads was created in a similar way, see:

http://mtfctulsa.com/Tech/heads.htm

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Larry I have 2 Jumbos, one has a PTO (aluminum case) and one doesn't (iron case). How should I get you the info? I'd rather not take them apart unless it's necessary.

These were bought over the last couple years in the hopes of having a low gear to climb hills without using the Ford low. Neither one has been installed yet. However if one or both of these was for a TT and the underdrive ratio is astronomically low, it won't be fun or do what I want. For this reason I think a web page would be extremely helpful for situations like this and I'll help however I can.

Craig

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Lary I have a 2 speed warford ( under and direct

in front of my transfer case of the Livengood 4 wheel drive unit, Me think it might make a great rock crawler. haven't had a chance to try it yet.

Bob

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There is no need to take it apart to see what you've got. Just take the top cover off and count the teeth. At the front you will have the constant gears which are always engaged. Then you will have a pair of gears for all except 1:1. My Muncie has constant gears of 19 on the input shaft and 17 on the lay shaft or counter shaft. Overdrive is 16 on the main shaft and 20 on the lay shaft, so the ratio is:

(17/19)(16/20) = 0.717

The underdrive is:

(17/19)(24/12) = 1.79

Like I say, if you find this too difficult, just give me the teeth counts.

The number I have for the Warford 2 under is 1.90. I think that was from an advertisement. That's quite a bit lower than a Ruckstell. They also made a 2 speed over which I believe was 0.81. I would love to have one of those with a 4:1 rear.

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Roger,

They weigh quite a bit. As I get older they seem to get heavier. I would guess something like 60 to 70 lbs (30 kg). That is about the same as any other 3 speed from that era. I've got a Laycock out of a Volvo that I want to try. Not period correct, but a small, lift and easy shifting unit.

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While I know that each company had multiple models, with different ratios in each model. Here is some of the information that has been given to me. I'm not sure where all the info came from but noted it when I could. I know I've found 3 different numbers for just the warfords alone.

I've been unable to find the Jumbo Giant advertisement flier that listed all the ratios for all of their models. I know it's out there one hit Ebay last week...just not worth the $50.00 they wanted for it.... I just want to read it once.

The Warford:

1st - 1.37:1

2nd - 1:1

3rd - 1:1.363

The Muncie:

1st - 1.792:1

2nd - 1:1

3rd - 1:1.397

The Jumbo Giant:

1st - 1.66:1

2nd - 1:1

3rd - 1:1.357

The Chicago Mark-E (numbers came from counting teeth on working unit)

1st - 1.500:1

2nd - 1:1

3rd - 1:1.556

Larry, I have all the numbers I found for the Warford if you would like. But it was an easy Google find, so you may already have it.

Thank you for the responses. I never would have guessed there was this much interest in Aux. Transmissions. The Depth and Breadth of knowledge here is amazing!

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Bruce, Thanks for the numbers. The Warford low looks a bit suspicious, but I'll compare/combine your numbers with what I've got and try to get a preliminary page up on the web. Maybe that will spark additional interest.

The interest in these old transmissions is easy to understand. I think the three Muncies I have cost less than one Ruckstell, plus I've got an overdrive gear! Who cares about a "lttle" noise? I've been wanting to build a roadster pickup to do the jeep trails out in Colorado and New Mexico. It would be about the right ratio and would save the triple gears.

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Looking at the 1.66 low of the jumbo.... how slow is that going to be in Ford high compared to driving in Ford low with no aftermarket trans?

Thanks!

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Larry,

I just compared my 2 Jumbo Giants. I was incorrect when stating one had an aluminum case - both are iron. Also both have the same number cast into the case (940T) even though one has a PTO opening/cover plate and the other does not.

The shift pattern is R and 3 across the top of the shifter (front of car), and 1 and 2 across the bottom.

I removed the shifter from one trans and looked inside. Due to the rails on top I couldn't hardly get a good tooth count on the top gear, let alone the bottom which I couldn't even see. I'm not against removing the rails so I can count the teeth but how am I supposed to see the bottom (countershaft?) ?

I'm very curious what ratios I have so I'm not agains disassembling both transmissions; I'd just rather not do it if I don't have to.

Craig

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Craig, you can mark the input and output shafts with a pen and count revolutions while you turn the input shaft by hand - gives a good approximation of the gear ratio.

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I have a copy of an article by Louis Baudoin that lists the ratios above for the Jumbo, Warford & Muncie. The Muncie is correct, but if you use his teeth counts, you find the other two are wrong. It should be:

Jumbo: 1.842, 1, 0.737

Warford: 2.037, 1, 0.734

That agrees with the Vintage Ford article 20-2-33.

That article gives the aluminum Warford as:

1.833, 1, 0.733

The Baudoin article is very good (despite the errors). Is it available somewhere?

Bruce, those Chicago ratios are bizarre. Are you sure you calculated them correctly?

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Here are some preliminary results. Not very useful with such limited input. This is set up in a spreadsheet which makes it easy to modify ratios.

3.64 ratioGears364.pdf (8.4 k) |

4.00 ratioGears400.pdf (8.4 k) |

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Your 37 Hudson transmission is synchromesh in second and high, I bet, which gives it an advantage over the others. Does it have an overdrive?

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This is great! I, too, have wondered for a long time about the exact ratios of the different auxiliary transmissions.

One problem I see, we need to be clearer with the statements on the ratio numbers. I don't know if it is truly the right way or not, but I was always taught transmission ratios were expressed as the input (1) to output (for example, 1.33) would be 1 to 1.33 or 1 to 1 1/3 for an overdrive.

That same ratio can also be expressed as a percentage over the one. That same example (1 to 1.33 over) would be expressed as a 33% over. I personally prefer this method.

Underdrive would be stated as 1 to .55 under or the percentage of 45% under. Note that the percentage statement flips to the difference for underdrive.

Most of the "big-box" auxiliaries, Jumbo Giant, Warford, Chicago, etc are about 33% overdrive and about 50% undrdrive. Your transmission will vary. The "rear-mounted" auxiliaries, Moore, Universal, Rocky Mountain, etc may be very different.

The first boat-tail roadster I had, several years ago, had a Universal three speed progressive-shift. I never had it apart and therefore never counted the teeth, so I don't know the exact ratios. But "turn-in" to "turn-out" came up right at 1 to 1 2/3 or 66% overdrive. That is about twice the usual. It came with the 10 tooth pinion installed and was a near perfect setup. 4 to 1 rear end gears (input to output again) was perfect for around town in direct. Overdrive was good on the open road (still a bit tall with a mostly stock engine). Underdrive was about 40% under and required just a tap of low-band then let out the clutch to get moving. It was almost as easy to shift as a Ruckstell, but you had to be careful to not over-shift through direct both up or down. I used to joke about having two neutrals to get stuck in. However it really didn't get "stuck" in neutral nearly as easily as any of the "big box" auxiliaries. In fact, I can't remember ever missing a shift and not getting it on the second try. And those few times were always when I "over-shifted" into that second neutral. I told you it shifted easily.

Thank you to you all.

Drive carefully (especially with those neutrals and brakes), and enjoy, W2

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I finally got to tear apart the Jumbos that I have (Both are Jumbo Giants). Glad I did - the first one I bought (with the PTO opening) has bad gears and good bearings. The second one I bought (no PTO opening) has great gears but the hyatt bearings fell apart when I took them out!

Turns out the PTO connection is simply the middle gear for reverse. The Jumbos that can be equipped with a PTO have the bump for this gear machined down so a cover or PTO unit can be bolted on. I'm wondering if this was done later in production and all Jumbos after a certain point have the cover or the additional time and expense to machine that off made it optional. Anyway, there are no additional parts in the one with the opening except for the cover and 4 bolts that hold it on.

I'm also having trouble figuring out the ratios. The top gearset has 3 gears on it. The forward gear is freewheeling and in constant mesh with the bottom gearset front gear. The back 2 gears on top are sliding. When the rear sliding gear goes back, it meshes with the extra reverse gear and the rear gear on the bottom gearset. The middle gear on top slides into the front gear on top when it moves forward. Here are the number of teeth on the gearsets:

Top (from front of trans to back)

19

16

25

Bottom

21

24

15

12 (reverse)

Extra reverse gear off to side has 18 teeth.

I figured out the combinations, here they are.

1 - 25/15

2 - 19/21

3 - 16/24

R - 25/18/12

If I do the math, 1st is 1.66 as stated before, but 2nd is .90 and 3rd is .66. I'm surprised that 2nd isn't direct if I did the calculation correctly. I also can't figure out how to calculate reverse. Can someone tell me what it is and how you figure that out?

Thanks, and I hope this also helps with info. I can provide photos while these are apart if anyone wants them.

Craig

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Thanks for taking on this challenge, Larry.

My favorite Overdrive is a Borg-Warner R-10G out of a Mopar. It is 10/7. Works good for my driving with 10/40 diffy.

Next in line is my HD model Langbein Underdrive with 5/8 gearing, mated to 13/39 diffy. It's quite a puzzle mating them, since the rearend halves have to be split to fit the 13 tooth pinion.

I also have this Langbein for a TT. It uses the opposite gear ratio as the one above, but the gears are not interchangeable between the two. It is 8/5.

I have never driven this one far, as it won't stay in gear due to wear. The other two Langbeins need gears also. I need to go see Les Shelley at Action Gear.

I also have a Rambler 3 speed with O/D I haven't used. That's just too much. I would prefer the 3 speed, or the O/D, not both.

Bottom Line, The T needs a 3 speed planetary: low at 3:1, 2nd at about 1.6:1, and direct.

Too bad Henry didn't proceed with what he patented in the 1920s. The Model A and later could have all used 3-speed planetaries up until they could have been mated to converters and hydraulics. He could have avoided the crash boxes entirely, and kept a huge captive customer base that had driven only planetaries.

rdr

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Do you have contact info for Les Shelley? I'd like to have someone look at these gears and see what the cost would be to have new ones made. It would be nice to be able to use both transmissions in a couple of my vehicles instead of only one with some spare parts left over.

Thanks

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Larry,

I compiled the ratios on the Chicago from my own Chicago Mark-E from my '26 Roadster. I counted the ratios 4 or 5 different times and calculated it out several times to make sure I had them right. I know the Chicago has a lower underdrive then the Warfords because I have driven them both and my crawl at an idol in Model T high/Underdrive with out a struggle. Also in overdrive my engine RPMs drop lower and I can walk away from a warford car easily.

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Action Gear & Broaching

1717 Monrovia Avenue, Costa Mesa, CA 92627-4406

(949) 645-8212 () ý

Les is at least second generation T guy. His siblings, cousins, whatever, are very active in the Orange County T club.

rdr

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Thanks rdr.

Clayton, the ratio listed for the Chicago overdrive (as well as all the others) above looks too low (they are all above 1.0). I only saw the ratios Bruce posted, what numbers did you get for the Chicago?

Anybody have any thoughts on why my 2nd gear (which I assume should be direct) is .90 instead of 1.0?

Craig

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Larry, where are you?