qwksilvr1

1930's Buick transmission open drive shaft adapter

6 posts in this topic

Has anyone made an adapter to mate an open driveline with a early 1930's Buick 3 Speed Transmission?

 

I have a 1932 Buick 57 series and I am trying to improve the RPM's at highway speeds.     Changing over to an open driveline will allow me change to a Ford 9" to get a wide selection of gear ratio's

 

Thanks

 

George

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Posted (edited)

You might want to google 'torque tube" before you get in too deep. It is a key part of your suspension system and is what transmits the torque of the wheels through a torque ball to the back of the transmission, through the engine mounts and to the cars' frame. It may have rods running to either side of it from the rear axle that serve to locate the axle from side to side. If your Buick is one with coil springs in the rear, the torque tubes' function is arguably even more critical than in a leaf spring car. Yes, I've done the street rod thing too, and I'm well aware that torque tubes are eliminated all the time. My point is that to do it safely requires more than eliminating the torque tube and installing a late model rear end. Even if the car has leaf springs, their mounting points were not designed to transmit the torque load to the frame. Rather than cutting the car up, I would recommend a Gearvendors overdrive. I did a topic under Technical a couple of years ago detailing the installation of one in a 1931 Cadillac Sedan. It accomplished what you want to do beautifully, and allows you to easily put the car back to stock simply by procuring an extra torque tube and inner drive shaft, as these are the only pieces modified. Also, you can elect to remove the overdrive for use in the next car if you sell the Buick. Good luck.

 

Edited by 31 Caddy (see edit history)

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10 hours ago, 31 Caddy said:

requires more than eliminating the torque tube and installing a late model rear end.

 

Agreed.   

 

A long winded reply but needs to be said:

 

These prewar cars of that age, had higher numerical rear axle ratios from 4.50-4.80.  That was done to have a good RPM-to-power ratio at the OLD road speeds of around 40-45 MPH.  The transmissions needed to have a "higher" ratio on first gear and reverse, to not be way too slow in those gears...  So, if you now switch to a 3.00 to 3.20 rear axle ratio, the car will be awful in first and reverse, and you need to "ride the clutch" to get it to move at all. 

 

Next issue with using a modern rear in that Buick, is that you now have cable brakes up front, and hydraulic rears.  You need to modify the fronts to hydraulic and use a master cylinder.

 

I am not aware of anyone modifying a 1932 Buick 50 series trans to open drive.  I do modify the biggest series 36-38 Buick transmissions to open drive by using the internals and tail housing from 51-64 Olds open drive transmissions.  I am confident that the 32 transmission design is way too different to do that.

 

Another issue with early cars is lack of power and torque when overdriving "by any system".  If you live near hills, you can have too much "gear" to maintain the speed on a longer hill, and you start losing speed, and then are forced to go out of OD, or downshift, and then be screaming the engine in the breakdown lane.  It is far easier to re-gear a prewar to be great on backroads and State Secondary roads where speeds are 50-55, compared to the "highway" speeds of near 70 in the slow lane.  If you re-gear with only Highway in mind, the car will be awful on those slower roads and when taking off in first.

 

All I am stating is that there is no one easy answer with lower powered cars and the vastly different speeds on various roads needed these days.

 

My 32 Nash has the stock flathead 6 and stock transmission.  It was open drive from factory.  I used a Ford 8" 1965 Mustang rear to be able to order any rear ratio I decided on.  These gears are available at $150 from online speed shops.  I did have to convert the front brakes to hydraulic and add a master cylinder.  I made changes to use the Ford e-brake cables with the Nash handle.  Then needed to plan ahead for the "wrong wheel bolt pattern" on the Ford rear end so I could use the Nash wire wheels.  My car won't see the "highway speeds" so I will use the 3.70 ratio so that it will be great on secondary roads where I want to drive.  If I wanted highway speeds, I would need more power and torque to handle a 3.00 ratio. Right now, the factory Mustang 2.78 gear is still in it, and you can barely get it to take off in first, due to what I said about the "high" ratio of the old transmission first and reverse gears.

 

 You can't have everything, with "just a rear end swap".  :(

 

.

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Posted (edited)

31 Caddy..... thanks for giving me another option....I will look into this.... I just happen to have an extra Torque tube and drive shaft for this vehicle... I had looked into seeing if a old Columbia rear end could be adapted to fit a buick but my friends in the Flat head ford club said they would kill me for modifying such a rare part.   Now modifying a spare torque tube to get to were i want to be might just be the way to go.

 

What was the model # of the unit you installed.... and what was the cost of this unit before all the machining work that needed to be done?

'

 

 

Edited by qwksilvr1
left out a detail (see edit history)

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F&J.... a 3.70 Ratio is exactly the range i was hoping to get to.. but I am going to look into 31 Caddys under/overdrive unit idea first as it might be the least invasive.

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On ‎3‎/‎22‎/‎2017 at 10:58 PM, qwksilvr1 said:

31 Caddy..... thanks for giving me another option....I will look into this.... I just happen to have an extra Torque tube and drive shaft for this vehicle... I had looked into seeing if a old Columbia rear end could be adapted to fit a buick but my friends in the Flat head ford club said they would kill me for modifying such a rare part.   Now modifying a spare torque tube to get to were i want to be might just be the way to go.

 

What was the model # of the unit you installed.... and what was the cost of this unit before all the machining work that needed to be done?

'

 

 

Gearvendors  refers to it as a universal torque tube kit. Check their website. I think it was like $2,500.

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