20 replies to this topic

[Mark B. Morrow]

In the article on the increase in mileage on the Super Duty, it was mentioned that the drawback in using higher gear ratios was a decrease in towing performance. That got me thinking of the Columbia two speed rear that Ford used in the 1930s. Why not resurrect this old idea and have the best of both worlds. Lower gears to be used for towing and higher gears for improved mileage the rest of the time.

http://www.hemmings...._feature21.html

[P71_CrownVic]

In the article on the increase in mileage on the Super Duty, it was mentioned that the drawback in using higher gear ratios was a decrease in towing performance. That got me thinking of the Columbia two speed rear that Ford used in the 1930s. Why not resurrect this old idea and have the best of both worlds. Lower gears to be used for towing and higher gears for improved mileage the rest of the time.

http://www.hemmings...._feature21.html

Because then they would have something the competition doesn't...and we can't have that.

[chromehorn]

In the article on the increase in mileage on the Super Duty, it was mentioned that the drawback in using higher gear ratios was a decrease in towing performance. That got me thinking of the Columbia two speed rear that Ford used in the 1930s. Why not resurrect this old idea and have the best of both worlds. Lower gears to be used for towing and higher gears for improved mileage the rest of the time.

http://www.hemmings...._feature21.html

Interesting thought. I'm not familiar with the unit Ford used in the 30's, but I am familiar with the one GM used in it's trucks in the 60's. We had an old '64 GMC 2-ton farm truck which had a 2-speed rear axle. It was kind of fun to drive as a kid...rowing through all those gears just for fun. Now to be honest, I could shift through all 4 gears and stay in low range (or high range for that matter), w/o going through all of them (i.e. 1 low, 1 high, 2 low, 2 high, etc...). On only a couple of occasions that I can remember did I have such a heavy load that 4 high was too tall and needed to go to 4 low on the highway. But that may be where one potential issue is. Many people may not like having to shift alot to find the right gear for what they are doing. But at the same time, today's technology would surely be able to simplify the process. It ought to be considered as an option for those who want it. Any ideas as to how much it might cost to implement?

[timmm55]

Ford had a prototype of a 2 speed rear end in a 1969 Mercury Cougar Eliminator.

[Sixt9coug]

yup, i have a copy of that Hot Rod around here somewhere. Too bad i dont have a scanner.

[silvrsvt]

I'd say the big reason its not used is that its too expensive and too complex at the moment? And that the theoretical savings of using it isn't as high as you would expect it to be.

[Marauder2299of7839]

ford used an Eaton unit from the 50-70s, as well as a Rockwell unit in the 70s-80s, both in class 5-7 trucks

the problem isn't the equipment, I doubt half the Neanderthals out there could properly use them. you need to let off the throttle when shifting, and wait for it to be fully engaged before applying power again.

a fool-proof overdrive is a safer way to reduce warranty claims.

[BigBadBflo]

If they can automate the 4x4 engagement process, they should be able to the same with these.

[MERKURXR4Ti]

True but the complexity is still there, and with 5-6spd trannies the savings will hardly be worth the engineering effort.

[NLPRacing]

Instead of a 2 speed axle, how about one of these Under/Overdrive units? I've been seriously considering one for my motorhome. Does anybody have any experience with them?

GEAR VENDORS UNDER/OVERDRIVE™

[theoldwizard]

True but the complexity is still there, and with 5-6spd trannies the savings will hardly be worth the engineering effort.

We have a winner !

[Ralph Greene]

Don't 6 and 7 speed electronically controlled current automatics do the same thing? The 6 speed Aisin in my wife's Montego has a very low 1st gear and a very tall 6th gear allowing 30 hiway MPG, allowing the use of a small engine (which Ford was criticized for and folks on here didn't understand the intelligence behind). Of course, it won't tow because of low tq engine. But in trucks, it could, if mated to proper engine and chassis. It would be easy to just keep it in one gear down from top, like my Explorer does with button on end of shift leaver.

Also....some of the manual 6 speeds (T 56's as an example), for heavy duty applications like Viper, have a .5 6th, for low RPM cruising. Then use 1-1 (4th) or .8 to 1 (5th) for towing.

The 2 speed rear really isn't needed anymore for light to medium duty use. But in heavy duty trucks, mayso so.

Edited by Ralph Greene, 03 January 2008 - 10:12 AM.

[old_fairmont_wagon]

My dad had one of thise Under Drive / Overdrive setups on his heavily modified 72 F-100 (Can't remember if it was a beefed up C4 or a C6 in there behind a 390FE with towing cams and a moderate overboar). It worked fairly well. It helped with towing the trailer in the mountains and with puttering around town. Didn't give us any problems while we had it. It was still on the truck when it was sold a long time ago.

[theVengineguy]

Think of system complexity. If i have two devices varrying ratios, what does that do to my FMEA, calibration, etc. So lets say you mate it to a 4R100, that gives you 8 speeds, which gives you better resolution on the gross power curve of the engine. But are you gonna argue by ditching 2 points on the gross power curve in favor of one device that varries ratios? I can see something like that for a tractor, but for an everyday driver no. I wouldn't want something to be so shift busy around the city, you would get ratios for take off at like 15-16:1, so probably 90% of the time, that ratio would be skipped, or be engaged for like a second. And think of all the ratios you skip over when you get to say 40-50mph. Even if you have an automatic, you can still lock and unlock your torque converter, so in torque multiplication terms that gives you 16 torque ratio outputs. Once again, you get the loss from the converter, but the torque multiplication options are still there. Hold the KISS principal... KEEP IT SIMPLE STUPID.

[xr7g428]

I would buy this for my '05 F150. I would love to have a low range for pulling in the mountains, and a high range for highway driving with just passengers on board. Maybe with the six speed automatic it might be just the same, but with the current transmission, towing in the mountains with a load means a lot of second gear driving. I'd prefer to have a little more flexibility.

[Marauder2299of7839]

Think of system complexity. If i have two devices varrying ratios, what does that do to my FMEA, calibration, etc. So lets say you mate it to a 4R100, that gives you 8 speeds, which gives you better resolution on the gross power curve of the engine. But are you gonna argue by ditching 2 points on the gross power curve in favor of one device that varries ratios? I can see something like that for a tractor, but for an everyday driver no. I wouldn't want something to be so shift busy around the city, you would get ratios for take off at like 15-16:1, so probably 90% of the time, that ratio would be skipped, or be engaged for like a second. And think of all the ratios you skip over when you get to say 40-50mph. Even if you have an automatic, you can still lock and unlock your torque converter, so in torque multiplication terms that gives you 16 torque ratio outputs. Once again, you get the loss from the converter, but the torque multiplication options are still there. Hold the KISS principal... KEEP IT SIMPLE STUPID.

if we were keeping it simple we would still be using C-4s and C-6s

I agree that for the typical driver neither the OD/UD or the 2-sp axle makes a lot of sence.
however there are a lot of non-typical drivers that could make use of 8-10 speeds.

[Furious1Auto]

In the article on the increase in mileage on the Super Duty, it was mentioned that the drawback in using higher gear ratios was a decrease in towing performance. That got me thinking of the Columbia two speed rear that Ford used in the 1930s. Why not resurrect this old idea and have the best of both worlds. Lower gears to be used for towing and higher gears for improved mileage the rest of the time.

http://www.hemmings...._feature21.html

I think that is a great idea, as long as they don't lose durability in the process! I two speed rear end makes a 4 speed tranny into a 8 speed, the extra gears they would gain could be spec'ed based on it's application. Good call Mark B. Morrow!

[fordtion]

Instead of a 2 speed axle, how about one of these Under/Overdrive units? I've been seriously considering one for my motorhome. Does anybody have any experience with them?

GEAR VENDORS UNDER/OVERDRIVE™

I had a US Gears under drive in a 1999/2000 F-450, works well when towing a 40 ft car hauler. It kept the diesel in the sweet range.

Then I installed US gear under drive in a a 2001 Lightning,thay was a of time and money.

With these 6 and 7 speed trannys coming about, I see no no need for a 2 speed axle or any type under drive....JMO

[Furious1Auto]

I had a US Gears under drive in a 1999/2000 F-450, works well when towing a 40 ft car hauler. It kept the diesel in the sweet range.

Then I installed US gear under drive in a a 2001 Lightning,thay was a of time and money.

With these 6 and 7 speed trannys coming about, I see no no need for a 2 speed axle or any type under drive....JMO

The more the merrier! Extra gears at higher speeds reduce RPM's and save fuel, while extra gears on the low end improve pulling/towing capabilities. I've driven construction trucks with deep reduction gears and highway trucks with as many as 18 gears. I can tell by your use of the words "sweet spot" that you are/were a trucker! A two speed offering is a low cost way to offer different gear ratios capable of handling different applications in comparison to the cost of designing new transmissions.

[commandermike]

Ford had a prototype of a 2 speed rear end in a 1969 Mercury Cougar Eliminator.

hi they did offer this rear end in the boss mustang and cougar eliminator...i ran across one that was in a 1969 Boss 302 Eliminator it had a switch on the Hurst shifter.