VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 rear end swap

I am getting ready to swap my 4:10 gears in my 47 for a 3:73 set from an early 50's car.I have read all the posting about swaping the torgue tube/carrier assembly. Can I swap the ENTIRE rear end assembly, put the axles from the 47 in the newer one to retain 6 bolt pattern ?

Also, How is the "Oakie Bushing" different from the original and how did it get that name? I'm not clear on what to order and what to do to use the Oakie. I assume you have to remove the old bushing first ??

The Oakie bushing was made in Oklahoma....

To install an Oakie it is necessary to remove only the front bushing. It is the one the rear U joint yoke rides in. Usualy not too difficult to remove. The Oakie is a single long brass bushing and is drive in till it contacts the present rear bushing. The advantage is that it rides on a portion of the drive shaft that was not in contact with the original bushings thus is not worn.A seal comes with it.

The complete rear end from a 1949 or newer will not work. The tread is not as wide (as the 1947) on those models and their axle shafts are shorter.

You mention a 3.73 for an early '50's car. The 1949 was the last year to offer a 3.73 as an option. The 1953-54 sticks had a 3.70 and a sturdier torque tube with different bushings than the 1949 and previous and the front bushing is pressed in and can be difficult to remove. It does use the same Oakie as a 1941 and up.

I can send you a private message with my contact number.

Thanks, I guess I should have thought of that. Sometimes the obvious is just overlooked.

Thanks for your information. Your expertise on Chevs is amazing. I checked my gears and I do have a 3:70 and a heavier torque tube which (as I understand it) means the rear end came from a 53-54 stick.
I assume the drive shaft bushing puller(rental in Chev's of the 40's) will get the old front bushing out and I should order Oakie Bushing as listed for 51-54 ?? Anything else besides gaskets(shims) for ball and gaskets for carrier & center cover that I should get before attempting the swap.
I can do minor repairs but this is pressing my limits so I appreciate all the info I can get before going ahead.

Thanks

chevgene- I will send you private msg.

In the 49 to 54 forum, there are some earlier posts by Dr Scotti who did the Oakie and a swap. It may be of assistance to you.

Bob

Hi I have a 1951 chevy 1 ton truck do you know what i will need to change the rear end so i can drive it faster than 50 mph THANK YOU For any help

Mr Dave;
Try Patrick's Antique Cars & Trucks 520-836-1117. They sell ring & pinion (3:55 to 1, I believe) for pick ups. Don't know if 1 ton uses same rear end or not.

You can use the rear end from a '70's truck, automatic 8 cyl, it will have a 4.11 ratio whch, with your larger tires, will equal a 3.70 ratio in a car.

I think he has the torque tube rearend.

was reading a old post about rear end swapping. I have a 47 coupe and was told that the ring & pinion gears from a 50-54 Zchve with automatic trnasmission would swap out with no problem. Can you verify this. Thanks rich S. Wolcott ct. Richmarlo40@Yahoo.com

What you want to swap is the torque tube and center section as a unit. The 1941-1954's are interchangeable.
The 1953-54 sticks had a 3.70 ratio and the 1950-1954 Power Glides a 3.55.

I have a 3.70 from a 53 in my 49. Another mmember of our region has a 3.55 in his 50. These are both tour cars and they run a lot easier. Gene is right about the swap. It is very easy to do.

I used ring & pinion from 50's powerglide unit about 40 years ago in my 47 & didn't know enough then to swap the complet carrier & torque tube as a unit. Just last year I swapped a complete assembly in another 47 and I agree that is the way to go. Sure makes it easier on the engine.

dick

Dick,
I'm thinking that except when the engine is turning in the relatively high rpm range (near "red-line'), that higher differential gear ratios (3:55 & 3:70) are actually a little harder on the engine than the lower 4:11 would be.

Maybe I've got it wrong. I'm open to being better educated on the subject.
Best,
Charlie

The 3:55 ration will result in lower RPM of about 14% and the 3:70 will result in lower RPM of about 10% at any given speed.

Dick

Dick,
I understand the ratio math, but the load resulting from fewer turns of the engine to more turns of the rear drive wheel(s) is absorbed by the engine, not the differential gears.

That's why, if you install one of the optional differential gear ratios you will notice a need for more power, from that previously needed with the old 4:11, to negotiate an incline or hill.

Think of a bicycle's gearing and the load placed on the rider by using different gears ratios.
Charlie

Charlie , in that sense I think your right...although I think their motive is to just "lope" along down the highway...I think...

Hi, The motive is to have the engine turn fewer RPM at cruising speed(55) for tours. It is correct that there is some loss of power on hills, but that is what the transmission is for. Put it second gear and there is lots of power.

I HEARD THAT THE RING & PINION GEARS FROM A 50-54 CHEVY THAT HAD A POWERGLIDE WILL FIT IN MY 47 COUPE. IS THIER ANY TRUTH TO THAT?

That is true.
The most common practice is to remove the complete torque tube and center section. That was it is not necessary to disassemble the gears.
The torque tube and center section from any 1950-1954 Power Glide will work
You can also select the above from a 1953-1954 stick. They has a 3.70 ratio whch mkes for qite an improvement and allows a little more power on hills.
A 3.73 ratio was optional in 1947.

WRONG! The Okie bushing was devised as a quickie repair to a bad torque tube bushing by those working on the Chevrolets owned by the pore folks fleeing the dust bowl and the "Great Depression" in the central US Plains back in the mid to late 1930s. They were the same folks that used a piece of leather belt or a bacon rind to replace the babbit thrown out of a rod or main bearing, along side of the road when they were trying to make it out to "The land of milk and honey!" (Cali-a-forn-ia)

I know about this because my family was too proud, and broke, to leave their homes and oilfield jobs in Oklahoma and migrate to the "land of Milk and Honey", and the oil fields of Bakersfield and Long Beach. Most of my family that had money made it out to the West Coast and lasted until they got good jobs in the aircraft plants in L.A. and Oakland, The really pore ones only made it as far as Colorado and a good number of them still live in Colorado.

Hey Charlie!
In a passanger car with a 216 you would have more advantage with a 3.70 rear axel unit, the extra load is more than balanced out by the lower RPMs, these long stroke sixes have a really good torque range under load as long as the RPMs are lower. Using a 235 and a 3.70 rear end makes the ol pre 1953 Chevys a nice smooth riding car with plenty of power in high gear climbing hills that a little rice rocket has to strain to get up. My 53 and several other 216 and 235s made the run up Mt. Scott in the Wichita Mountains in high gear without any problems, Ford flatheads usually have to downshift to second and get on top with the radiator steaming like a steam engine.

I agree with Mr Mack, These old 6 cylinder, long stroke Chevrolet engines don't like high RPMs but have great low end torque. I tried the high RPM thing when I was in high school and killed off a couple of them! I have lugged the heck out of them pulling trailers with no bad results.

Mr. Mack - Thank you!

You are the first gent in the 3 years I have been a member of this fine club to attest to the use of either belt leather or shoe leather for repairs to a bottom end of an engine! Brings back some wonderful memories of the discussion between Dad and I as he was telling me of this during the 30's.