Torque Tube Stuff

[JimShelly]

Greetings and Happy New Year to all.
I'm contemplating the next round of work on my 1939 41C. I've cut the torque tube and fit a Gearvendors overdrive into it. Now I have to pull everything apart again and have the two driveshafts balanced. As I go back together, I have to align the rear of the transmission and the torque ball. I also have to get the shimming on the torque ball just right. I think it is set up a little too tight right now.

Is there anyone out there who is experienced with the torque tube setup? I'd really like to speak with you.

In addition, does anyone know if the inner driveshaft will simply pull out of the rear differential? The shop manual diagram doesn't really tell me.

Thanks in advance. Jim

 

[Bob]

I have not worked on one that old, but my parts book show that it uses a retaining pin typical of the later ones which I have played with. The rear end is grouped 1940 to 1955. If so, the pin is tapered and comes out in one direction and the shaft uses a special puller for removal and installation. I was able to remove the shaft without the special tool (I don't remember, but probably used heat from an oxyacetylene torch). I was fortunate enough to not have to reinstall the OE style driveshaft as one of my parts cars had a relatively new aftermarket shaft installed which did not require the special tools.

 

[1939_buick]

Most definitely a pin. Been told very very hard to remove. Item W in the image. Need to get the torque tube off the housing first.
1940 and later had the torque tube flanged to the diff housing. A lot simpler than the riveted 1939 and earlier design.
The other image is a 1939 46C with gearvendors o/d. Photo sent to me by another 1939 owner


Edit
May help 1-->For you Buick Torque tube guys thats want to change gear ratio (shows that pin)
May help 2 --> 55 Special drive shaft won't seperate from pinion (many of the embedded images are gone due to software changes [I have a copy of those]}>>

 

[suntreemcanic]

The torque tube keeps the rear end in place. How are you going to keep the rear end in place with the gearvendor gear case in the middle? I know you have it figured out. Please share with us.

 

[JimShelly]

Thanks for the replies. I'll study them carefully later this evening. jns

 

[JimShelly]

The torque tube keeps the rear end in place. How are you going to keep the rear end in place with the gearvendor gear case in the middle? I know you have it figured out. Please share with us.

Gearvendors sends you two couplings for each end of the overdrive. The inner ones are gears which mesh with the input and output of the overdrive. We turned down the shafts of those gears until they would slip into the original driveshaft, then welded the two together. The outer couplers work the same way with the torque tube itself. We opened up the center of those couplers to the diameter of the torque tube and welded the two together. When the couplers are bolted to the overdrive they essentially make a solid piece of exactly the same length as the original torque tube. It took some amount of cut and paste to get the lengths right but we got there in the end.

 

[1939 46C]

See below pics from 2 other set ups who did the change over