The Ford "Skyway" Columbia Overdrive

Before the Borg Warner R-10 and R-11 electric overdrives became popular in the 1940's there was the Columbia overdrive rear end overdrive option. It could be installed by the local Ford dealer and offered a higher top speed and more important a lower engine rpm at normal highway speeds. The ratio of the Columbia overdrive was 28% very close to the 33% of the later Borg Warner electric overdrive. Unless you grew up in the era, you likely do not know much about a Columbia overdrive or how it operated. So stay tuned as you get a crash course in Columbia 101.

The Columbia overdrive rear end was an early design overdrive that was adapted to the stock Ford rear end housing, and was designed to provide a dual ratio for the rear end. The Columbia rear end was an option from Ford beginning in 1934 (could be retro fitted to a 1933) and prior to the Borg Warner overdrive transmissions which would become a Ford option beginning in 1949. It was the Borg Warner overdrive transmission that would later contribute to the demise of the Columbia dual-ratio rear end. Lets learn more.

Originally developed by the Columbia Axle Company in Cleveland, Ohio, the two-speed axle was first used as an option on the 1932 Auburn. Ford first offered it as a conversion for their 1934 models; it was later offered as a factory-option on the 1937-'41 V-12-powered Lincoln Zephyrs, Continentals and Custom models, and 1939-'41 Mercury's and Fords with the Flathead V-8.

The axle was supplied as a kit to be installed by Ford dealers or by independent authorized garages. Only a few of the 1933-1934 kits were sold, and they are considered very rare today. The axle was redesigned and improved for the 1935 Ford model year, and by mid-year, was called the Columbia “Two-Speed Axle” even though the differential carrier casting (A-6) was still marked “Dual Ratio Axle”. The axle was also an option for the new 1936 Lincoln Zephyr and later, the new 1939 Mercury. Ford, Mercury and Lincoln Zephyr cars could be ordered with a Columbia but it was installed by a Ford authorized independent shop before delivery. 

When the Columbia rear end unit was fitted to the original banjo-style Ford rear-end, the driver's side axle and the left axle housing were retained, but the passenger-side axle and housing had to be replaced. The new right side axle was shorter to make room for the planetary and sliding clutch assembly. The new right axle housing incorporated the mounting bracket for the vacuum canister and an opening for a shifting lever that was attached to the end of the canister's vacuum piston. 

The piston rod had a clevis assembly that attached to the sliding clutch. When the axle is in low gear, the sliding clutch is engaged, locking several planetary pinion gears and a center sun gear into a sort of "reverse flywheel" cut into the inner diameter of the ring gear. The outer ring gear then turns the axles. When the overdrive is engaged, the vacuum canister retracts the sliding gear and stops the sun gear from spinning. This allows the differential ring and pinion to spin freely and causes the stationary clutch to engage, allowing the ring gear to rotate the internal pinion gears. The sun gear, however, stops rotating when the sliding clutch is disengaged. The rotation of the ring gear turns the pinion gears about the sun gear, which allows the "reverse flywheel" and the axle shafts to rotate in the second speed.

Starting in 1937, the marking on the differential carrier casting was changed to “Two- Speed Axle” or “Overdrive Axle”. ’46-’48 castings were marked “Overdrive Axle”. 

In 1940, Mr. E.L. Cord sold the Columbia Axle Co. to a Cincinnati investment group represented by Messrs. W.E. Schott (who already controlled a sizable number of auto-related businesses) and Lewis Goldsmith. These two men became the new President and Vice-President, respectively, of the Company. Production and distribution of the two-speed axle continued as before, however, they were not available from 1942-1945, due to WW II. Production was resumed in late 1946 with Ford and Mercury dealers obtaining the axles from the Truckstell Company, with distributors located at key points from coast to coast. The Columbia Overdrive was now called “Skyway Drive” and had a new electric control, to activate solenoid, instead of manually as it was prior. 

The 1949 introduction of the new all electric shift Borg-Warner overdrive transmission option by Ford, made the Columbia overdrive obsolete, which spelled the doom of the Columbia Axle Co. However, parts and complete axles for pre-1949 cars remained available for a few years after. In late 1948, the Kaplan Auto Parts Distribution Co. of Cleveland Ohio purchased the Columbia inventory and took over the distribution of axles and spare parts. Kaplan did an active business through out the ‘50’s and into the mid ‘60’s when the supply of key components (new and used) had dwindled and the supply of whole axles was depleted. In 1968, Kaplan scrapped the last of its inventory) and the company closed. 

The first thing a driver had to remember about his Columbia, is that the car must be moving when the Columbia is shifted into overdrive... and also when it is shifted out of overdrive. To shift into overdrive, the dash control (lever on ‘35/’36, knob on ’37-’41, and spring loaded electric switch on ’46-’48) is activated (turn lever to “H”, pull knob, or hold down switch). The driver then takes his foot off the accelerator pedal (to create maximum vacuum) and fully depresses the clutch, which completes the shift. On ’46-’48, the driver also then releases the spring loaded dash switch. To shift out of overdrive, the driver returns the dash control to the standard position (on ’46-’48 the control switch automatically returns to standard position), takes his foot off the accelerator pedal, and fully depresses the clutch, which completed the shift. 

When the Columbia is shifted into overdrive, the sun gear is locked to the differential carrier casting so it cannot rotate. In this mode, the planetary gears rotate around the sun gear and, in turn, rotate the inner gear 28.5% faster than the differential outer case assembly which encloses it. Since the inner gear carries the pinion gears, the net result is a 28.5% reduction in RPM from the differential outer case assembly forward to the engine. 

Shifting from standard drive to overdrive and from overdrive to standard caused a sudden and substantial shocks to the gears, bearings, and housings of the Columbia axle. To absorb these shocks and to lock the sun gear in either standard drive or overdrive mode, the axle has a brake-clutch mechanism called the synchro clutch. The synchro clutch became the weak link of the Columbia overdrive.

Car owners trying to shift out of overdrive without the car moving also caused a lot of problems.

The real design downfall of the Columbia overdrive, is that the Columbia rear end receives about 4 times the amount of torque that a transmission or drive shaft overdrive unit does, due to the fact that it is located downstream of the ring and pinion. The failure point of a Columbia is almost always the internal planetary ring gear which is part of the differential housing. The failure often occurred when the driver attempted to take off from a standing start in low overdrive.

When the Columbia dual ratio rear end was introduced in the early 1930's, most cars had 4 cylinder engines. By the late thirties the V8 had been introduced and the horsepower of cars had more than doubled, which put even more strain on the Columbia rear end. 

So while the Columbia overdrive concept was a good one, the location of the overdrive unit itself, was not. The Borg Warner electric overdrive transmission offered a 33% reduction at engine speed, was factory installed, cost about the same money, and was easier to operate. The Borg Warner overdrive transmission would soon be offered as an option by eleven different car companies.

The local Ford Dealer in Clay Center Kansas, John Mouse Motors ran a quarter page add in the local newspaper in the spring of 1948 offering the "Skyway" Columbia overdrive for $89.50 plus installation. That is equal to $943.00 in 2018 dollars. So when Ford offered the Borg Warner electric overdrive option for $30.00 beginning in the 1949 model year, sales were brisk. 

For reference the $30.00 option is equal to $306 dollars in 2018, so it was no wonder the Borg Warner electric overdrive transmissions sold so well. Borg Warner sold well over three million of the overdrive transmissions by 1960. Studebaker sold the most Borg Warner overdrive transmission options. The Borg Warner electric overdrive was easier to operate and cost about a third of the Columbia option. Within a year of the introduction of the Borg Warner overdrive, the Columbia option was discontinued by Ford.

You will still see a Columbia overdrive rear end under an antique vehicle now and then, and their are now parts being reproduced with upgraded engineering to address some of the original weak points of the original Columbia overdrive rear ends. 

The purpose of this tech article is to give you a little basic knowledge of the Columbia overdrive rear ends so you will know what you are looking at when you see one, and to have a basic understanding of how they work.  Class dismissed!

1939 / 1940 Ford Battery Gauge And Upgrading To 12-Volts ...What You Need To Know

Starting with model year 1939, Ford installed a "Battery" gauge in the dash of their Deluxe model Ford, Mercury and Lincoln Zephyr model cars, instead of an Ammeter. No one seems to know why this happened, some speculate that there was a shortage of Ammeter gauges or that production could not keep up with demand. It doesn't really matter as long as you know how to identify what you have in the dash. The use of a "Battery" gauge in the Deluxe models continued into the 1940 model year.  The Battery gauges used in the Ford, Lincoln and Mercury models are marked with the colors of Red, Orange, Green and Red again at the top of the gauge markings.

Here is a 1940 Ford truck Ammeter

If your dash gauge doesn't look anything like the one described above, but instead, the dial says DIS and CHG  with the needle in the middle, you have an Ammeter instead. When you upgrade to 12-volts, you do not have to do anything to the Ammeter, because an Ammeter measures the volume of current...not the voltage. Again all standard model cars, and the trucks got Ammeters instead of Battery gauges.

If you have a Battery gauge in the dash...which in reality is a volt meter, (although not calibrated as such) the Battery gauge is designed to display the amount of voltage present in the electrical system when the ignition switch is in the "on" position.

1939 Mercury Battery Dash Gauge

The markings on a Ford Battery Gauge are as follows...Green was normal operating voltage, and represented a voltage range from 7.1 to 8.25 volts. The Red on the high side identified voltages of 8.25 to 9.0 volts. The Red voltages on the high side were unsafe for light bulbs, and often resulted in the water being boiled out of the battery from overcharging. Excessive generator voltage output (from stuck points in the regulator) can cause permanent damage to the generator. (All Ford Lincoln and Mercury Battery Gauge markings represent the same thing.)

The Orange sector represented voltages from 6.2 to 7.1. When the needle dropped below the green on the dial but stayed in the orange that meant the headlights and electrical load was equal to the generator output, and no current was being replaced into the battery. If headlights were not on such as daytime driving it meant the generator was not recharging the battery and the charging system may need attention.

If the needle dropped into the Red on the bottom of the scale, it represented 6.2 volts or below a warning to the driver the charging system was not keeping up with the electrical load and the current in the battery was fast being used up.

This is a backside view of a Ford Battery Gauge.  Battery current flows thru heater wire which in turn heats the bi-metal which moves the needle on the front side of the gauge.

The battery gauge on the left is the 1939 design, while the battery gauge on the right is the 1940 design. Remember it was just the deluxe models that got the battery gauges, the standard models along with the trucks got the ammeter gauges in the dash.

Part of this information on the Ford Battery gauges came from a Ford service bulletin dated October 1939. I wanted you to be able to read and understand a Ford Battery dash gauge, and also know the difference between a Ford Battery gauge and a Ford Ammeter. 

So now the burning question becomes...what do you do with the Ford Battery gauge that is calibrated for 6-volts, when you upgrade your Ford electrical system to 12-volts? 

The answer is simple! Install a "Runtz" voltage drop onto the back of the battery gauge just like you will do for the gas gauge and the rest of the electrical dash gauges, (water temp, oil pressure) and you will live happily ever after. The "Runtz" will reduce the 12-volts down to 7.75 volts which will be in the "Green" markings in the original Battery dash gauge. The Battery gauge will then function just like it always did.

I know that often times the solution from the experts is to just swap out the "battery" gauge for an "ammeter" gauge and everything will be fine. That will work, but the gauge face of the Ammeter gauge will not match the rest of your gauge faces.

Now that you know the simple solution of installing the Runtz onto the original Battery gauge which allows to keep and use all of your stock gauges, the upgrade to 12-volts just became that much easier.

The Thirty Year Education

2018 marks the 30th year of my education with the Great Race. That's a long time for an education, one that will likely continue for a few more years to come. A lot of you ask why I am still involved with the Great Race after thirty years and what exactly I get from it every year, that makes my involvement worth while.

A Little Background Is In Order...

Back in 1985 I invented a 6-volt alternator for antique vehicle applications. My 1951 Chevrolet pickup was the reason for the invention of the 6-volt alternator. I bought fixed up and sold dozens of these 1948 thru 1954 Chevrolet pickups in my high school years from 1972 thru 1976. I learned to always park on a hill to be sure they would start. I had first hand knowledge of dead batteries, dim headlights, and hard starting. I reasoned that if I was having trouble with my 6-volt electrical system, so was everybody else. I decided the 6-volt electrical system needed fixing, and I was just the guy to do it.  Besides...when you are young, you know everything!

How hard could it be...? If I had only known. I ended up spending all of my money figuring out how to make the 6-volt alternator work (and not work), so I had little money left for marketing. I did sell about a hundred of them locally over the next year, so I knew they worked, but I soon figured out I needed to find some new customers out of state, if I was going to continue to sell my 6-volt alternators. 

So...I started Fifth Avenue Antique Auto Parts in 1987 to market my new 6-volt alternator nationwide. It was in 1988 that I found out about the Great Race in which  they drove pre 1942 vehicles 4500 miles across the United States in two weeks time. I decided that was a perfect market for my new alternator. So I acquired a list of the entrants and started knocking on doors trying to convince one of the Great Race entrants to try my new alternator.

This 1951 was a one owner truck that I bought in 1972 when I had just turned 14. I still have that truck (it looks much different now ...and so do I) and it still has 6-volt alternator number one installed, which still works!) 

 They all asked the same thing..."have any other of the Great Race entrants tried them...? "  Not yet "but they should"... was my reply " because they work "... " Well you know there is no such thing as a 6-volt alternator..." until now... is my reply." well come back and see us when you get someone signed up and we might try one then "..that was how it went until I got to number 12 on the list, one Bud Melby of Seattle Washington.

Bud drove a 1936 Cord in the Great Race, a car I had never even heard of a Cord till then. Oh...great I say to myself, I get a car I know nothing about and never heard of, I will never sell this guy an alternator! But...Bud was more than receptive as he explained that the generator charging system in his Cord could not keep up with the additional electrical load from the electric fuel pump, the electric radiator cooling fan and the related accessories. 

He said he changed out the battery at noon each day, because when the battery voltage got low, the transmission would get stuck in overdrive. A Cord is all electric shift on the steering column and the overdrive is also electric shift. In the Great Race the car was being shifted way more often than it would be in normal driving, which was part of the reason for the dead battery.

I knew my alternator could fix that but I had to convince Bud. I finally said..."I will give you the alternator for free and if it works to your satisfaction then I want an endorsement from you at the end of the race. " Fair enough " he said.  He installed the alternator entered the 1989 Great Race and drove the entire race on the same battery!  He later said..." I couldn't believe it...some farm kid in Kansas invents this 6-volt alternator and tells me it will work on my car. I truly had serious doubts but figured it couldn't be any worse than what I had now. But that alternator actually worked just like he said it would! "

It was Howard Sharp that parked next to Bud each evening during the 1989 Great Race. Howard was driving a 1929 Dodge Sport Roadster one of only 1200 made. He too was having battery problems so Bud showed him his 6-volt alternator. Howard's response was..." if something like that would work they would have figured that out a long time ago...!

This sun faded picture is in the display case in my store. When Howard won in 1993 I asked for the winning alternator back and I sent him a new one. I wanted the alternator for display. It was my first win and was proof my alternator worked.

Howard watched that alternator the whole race and while he was charging batteries each night Bud never touched his. Two days after Howard got home from the race he called. He said..." That 6-volt alternator you sold Bud Melby, I want one for my Dodge, how soon can you get it here! " I sent him the alternator he installed it and drove it in the next two Great Races finishing in the top five both years. Like Bud...he never again replaced a battery.

In 1993 Howard won the Great Race and collected $30,000 and a new Buick car. He was now a believer in the 6-volt alternator and has became my best salesman. Soon other entrants in the Great Race discovered how Howard went from swapping batteries every day to not touching his battery the whole race. The word was out and the alternators began to sell to the Great Racers.

Another benefit I hadn't counted on from being involved with the Great Race, was the local car collectors who came down to look at the cars entered in the Great Race each evening, to see how the cars entered in the Great Race were different from the ones they owned. They would see the alternator with the gold sticker on top, and write down the phone number. 

The next day they would call and say..."I talked to one of the entrants in the Great Race last night and I want the same alternator he has, for my car. " The Great Race became my best advertising as antique car owners could see the alternators installed on a car and could talk to the Great Race car owners firsthand to learn all they wanted to know about how the alternators worked.

Meanwhile...

After the alternator secret made the rounds a few of the Great Racers led by Bud came to me and said..." you fixed our electrical problems, now we want you to fix our overheating and our vapor lock problems..."

So that is how I got involved with the Great Race in depth. They came to me with problems and I worked on finding a solution. They tested my new products and I knew if what I designed survived the Great Race it would survive anything the average antique vehicle owner would need. This has been going on for 30 years now, and is how most of the 40 specialized products I now offer for sale, came about.

Today, the Great Racers will drive 3500 miles in the Great Race in just two weeks time. They drive on much more difficult roads in much more extreme temperatures for much longer periods of time, than the average antique vehicle owner does. If they can break or abuse a part they will.

After Howard won the Great Race in 1993 he moved up to the expert class. He decided to take advantage of the age factor and buy an older vehicle. I get a call..." Hey... I just bought a car for the Great Race...it a 1911 Velie and I need an alternator for that car, so send me one when you get one built...and he hung up the phone.

This became one of the most expensive alternators I have ever built. The Velie has an idle speed of just 450 rpms and a maximum engine speed of 1200 rpms. 

Once again, I had no idea what a Velie was... so I did my homework. I found out the idle speed was just 450 rpms and the max engine rpms was 1200 rpms. I knew Howard needed an alternator with at least 30 amps at engine idle and at least 70 amps at highway speeds. Most alternators start charging about 800-1000 rpms and are designed to produce their full rated output at about about 4500 rpms engine speed. This would be a challenge. 

In the end using a special built one off high output stator and rotor assembly, (along with every trick I had learned in years past to extract more amps out of an alternator at low engine rpms), the alternator worked and more important proved to be reliable.  It became the most expensive alternator I had ever built to date, but it did deliver 40 amps at Velie engine idle and 74 amps and Velie highway speeds of 1200 rpms.

All was good till about 2006, when I get another call from Howard..." the route next years goes up Pikes Peak in Colorado, how are we going to keep the Velie from overheating at high altitude? I knew if Howard was onto the case, the rest of the Great Race entrants would be soon enough, so I needed to come up with an answer.  

Evans Coolant boils at 370 degrees and freezes at minus 80 degrees with no pressure in the cooling system. It has proven to be a lifesaver for the cars entered in the Great Race.

After six months of intense searching I found Jack Evans who had invented a waterless coolant that boiled at 370 degrees and freezes at minus 80, with no pressure in the cooling system. I knew immediately I was on to something so I spoke with Jack numerous times explaining what the application was and that I wanted to know if his coolant would work in a 1911 engine? While designed for modern high performance applications like the Corvette, he agreed to send me some of his coolant on a trial basis.

He explained the temp gauge in the dash will read 15-20 degrees higher as the Evans coolant will physically draw more heat from the engine and suspend it into the coolant, which will make the temp gauge read higher,  but the block will remain cooler. I knew as long as the coolant wasn't boiling it was still able to absorb heat. The Velie would prove to be a good test for the Evans Coolant. 

Well...much to everyones amazement, the Velie made it to the top of Pike's Peak without overheating. The Evans Coolant worked! It proved to be even more of a test, due to the fact that the Velie lost half of it's 40 horsepower climbing to the top, which made the engine work much harder and in turn the cooling system also work that much harder. There were lots of Great Race cars stranded on the way to the top and the Velie should have been one of the first casualties. It really struggled to get to the top and was only going about 3 mph when it reached the summit. It was a sweet victory for me and the Sharp racing team. We had conquered the mountain.

The Velie proved to be a challenge to drive in the Great Race each year. Howard's arms got as big as his thighs from the Armstrong power steering. With the alternator, the electric cooling fan, the electric fuel pump and the rest of what I had learned to date had made the Velie rock solid reliable much to the amazement of the other Great Race entrants. The Velie was the oldest car entered in the race most years, and it always finished in the top five, but gravity always seem to win at a crucial moment. The Velie had trouble pulling some of the long step hills on the Great Race routes.

Then in 2011 the Sharp Racing Team wins the Great Race driving the oldest car entered in the race, the same year the Velie turned 100 years old! All of the things I knew (or at least thought I knew) proved to be correct. It became pretty clear to me that if I could make a 100 year old car reliable I could make most any antique vehicle more reliable and fun to drive!

The Velie earned a well deserved retirement in 2011 and was replaced by a 1916 Hudson Speedster. Here we go again! So the Hudson got the same treatment that the Velie did and in 2015 the Sharp Racing Team won the Great Race again!

                                   Howard and Douglas Sharp in the 1916 Hudson.

And so it goes... every year the Great Race route presents new challenges, and new customers mean working on different types of antique vehicles. While all of the preparation to the electrical cooling, and fuel is basically the same, each individual antique vehicle is unique. But... after 30 years of preparing Great Race cars I pretty much have things down to a science. Having the car you prepare for the Great Race, win now and then, helps confirm that you are getting it right. It also help draw in a few new customers who now know without a doubt, that you know how to make an antique vehicle reliable.

That is what makes this fun for me. I enjoy the challenge, and the chance to learn something new. I tell people that preparing cars for the Great Race will teach you two things....it will separate what you know... from what you think you know... and you will learn that what is supposed to work in theory... does not always work in real life.

So when you call and ask me questions about the electrical cooling and fuel systems on your antique vehicle...now you know why I can give you an answer right away without hesitation. I do this every day for a living, and have for the past thirty years. So... yes I can make most any antique vehicle more reliable and fun to drive, including yours!

This car was built in 1960 as a parade car.  It was built using two 1939 Chevy car front ends. Both ends steer. The 6-volt electrical system was recently upgraded to a Fifth Avenue 6-volt alternator to make it more reliable in parades. It is still owned by the same family of the original builders. You can read more about the history of this car in another Garage Tech entry. 

Regular customer's antique vehicles have included...cars, trucks, tractors, buses, airport tugs, wooden boats, railroad track inspector cars, airplanes, stationery engines, backhoes, shovel cranes, fork lifts, semi trucks, fire trucks, and about most anything else you can think of. They all have something in common, the same electrical cooling and fuel issues. Ironically the same cars when used in the movies also share the issues, which is how I got into the movie business.

When a customer calls and asks..." Can you help me make my antique vehicle more reliable,  and I begin to explain the process, I will ask them how many miles they drove their antique vehicle last year? " 300 miles...less than a thousand...not as many as I'd like..." are common answers. When I ask why..."doesn't start good when it's hot"..." headlights are dim so I can't see after dark "... " every time I go to start it the battery is dead "...are the common answers.

So imagine that same car owner who once drove his antique vehicle only 300 miles a year because it was not reliable... now puts 3,000 miles a year on the same vehicle because it is now... just as reliable as his modern car. He is now a proud owner of an antique vehicle that he has confidence in driving,  and the smile on his face is a mile wide! He can truly enjoy his antique vehicle. That is the rewarding part for me...when a new customer hits the starter for the first time and the antique vehicle immediately starts..the look on their face is priceless.

And it was because of my thirty year Great Race education that we are both smiling!

And my job is done...