Columbia rear ratios

solidaxle

solidaxle

Well-known member
What do you guys think. I'm installing a Columbia two speed. I have 3.54gears, 39 transmission, 7.00 x 16 tires. Is this to tall with the columbia? Running just the stock banjo it always seemed like I need one more gear. Should I change the ring and pinion to 4.11?
 
It will work but The 4:11 will work better or a 3:78. I had a 47 coupe with the 6 cylinder and it had a Columbia with a 3:54 gear and it pulled it fine but it had 600x16 tires on the rear. If you’re driving in mostly flat ground it’ll be fine. If you’re in hilly terrain you’ll hate it.
 
I have a 4.11 in mine, if I did it again i would have 3.78 in the midwest plains. mountain states, maybe 4.11. where do you drive, how much on the freeway, its all relevant.
 
I think it depends on your engine. I have a '51 coupe with a straight transmission (no overdrive) and 3.55's. I have a pretty stout Mercury engine in it, and everything is fine with it, except that I keep wanting to "grab that extra gear" on the highway. I was thinking about picking up a 4.11 "chunk", but decided that I will stay with the 3.55's for the time being.

I'm not going to win any drag races anyway, and I think I'll be able to pull them at anything over 60. (Things are also pretty flat up here in north central Minnesota.)

EDIT : I forgot to mention that I am putting an OD transmission in the car this summer.
 
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I have 3.78 gearing in my 32 and I like this ratio with my Columbia. Delightful and quieter cruising.
 
I have 4.11 in my columbia, a 39 trans with 16/28 cluster, and 235/75/15 tires and a 59a in a 40 coupe. I live near Pgh. Pa. mostly hilly around this area, and the speed limits here are around 25 to 45 MPH. which is where most of my driving takes place and the 4.11 are great. On the 4 lane roads 65 or 70 MPH in overdrive is still doable. So for my area a 3.78 would be the only option I would consider if I was to change the rear. Put in the ratio that is best for the area you will be driving in.
 
Forgot to mention that I have 1939 transmission with 25-22-18-14, 19T main, Zephyer gears in the roadster.
 
It is important to consider the final overdrive ratio - given your tire sizes. I'm building a Columbia for my 32 with a 4.44 (because I have a very big cam in it and I'd like more low-speed acceleration). The OD ratio is 28%, so my final gear ratio will be 3.2. With this gear ratio and my tire size of 29.5" in the rear, it will be running about 2550 RPM at 70 MPH - which is just fine by me. If I started with 4.11 gears, the final ratio would be 2.96 - or 2360 RPM at 70 mph. Both of these RPM ranges are just fine for me and my style of driving.

Now - if I was going across the United States at 70 mph, then I might consider the 3.78 gears as my starting point - they'd drop the RPMs to 2177 . . . which would be about perfect for long distance driving - yet still give the car have enough acceleration from a standing stop to please the driver. It all comes down to what you want out of the car, where you plan to drive (and how much), etc..

Also, consider the whole package (like your brakes, suspension, steering, tire type, etc). I'm not sure I'd like to be traveling in my 32 Cabriolet at 70 mph for many hours at a time . . . even with all new suspension, Lincoln brakes, etc.. It could use some sway bars, it could use some seat belts, it could use a lot of things to make a long trip at 70 mph a more pleasant ride.
 
Here's a chart, don't know how to make it larger though
 

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It's mostly hilly to flat around here. I prefer staying off the major highways. Motor is a stock 8ba 239 with a blower. I had the car for 7years so I know how it takes the hills with the stock 3:54 gears. At times I need to shift down to second on the back road hills, revs are up and mph is slower, I'm thinking it's only a plus to have the 2-sp, I can then up shift 2nd high. My concern is on the flat or marginal hill it will fall on it's face. My thought is, as others have suggested the 3:78 would be a good choice but is it worth the effort to go from 3:54 to 3:78? It's not that big of a jump.
 
Ratio comparisons that I have for my roadster
 

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Thanks guys. I leaning on leaving the 3:54 in and see how it goes. The Columbia can only improve things even with the 3:54's. I should have it on the road again in a couple of weeks and let you know.
 
cropped and larger without fussing the text. Thought Kurt's post was big enough.
 

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I have had Columbia overdrives in my 1936 4 dr sedan, in my 1936 panel delivery, and also in my 1947 Sportsman. All were stock engines for their years. I used 3.78 rear axle gears in all of them and I was very happy with all of them. Unless you live in a flat area, 3.54 gearing wouldn't see much Columbia overdrive use.
 
So I have been looking for 3:78 gears. What years would fit my late 32 banjo. It's the wider center section and the scalloped torque tube connection. I'm not seeing anything at Mac's, C&G, Early Ford parts except the 28-32 ones.
 
The later 32-34 ring gear and pinion will fit your late 32 housing. Difference between it and the later 35-48 banjo housing is that it is narrower.
 
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