transmission

[out back machine]

Hi
my ? is I have a 29 double A that I am putting back together.
it has a new motor installed, new 1930 rear end installed. this is how
I got the truck so now I want to install the tans, and coupler shaft. and the info, I have found says the coupler shaft can not be put in unless the rear end is moved back ? . please don't tell me this is true, how can I get the shaft in place the way its set up now.
thanks for your time

[Bob C]

I think unless you have a 4-speed and the service replacement
coupling shaft you will have to remove the rear axle. How about
some pictures?

Bob

[SeaSlugs]

i know on a 29 with worm drive and dual high trans (sits in place of coupler shaft) the rearend must be removed to install dual high...dual high is last to be removed and first to install, then rearend, then engine/trans.

[Joe K]

See the pix above by Bob C. The coupler shaft can be taken out (or installed) after the engine is taken out.

The rear axle spherical joint clamshells mount to the "backside" of the middle crossmember. The trumpet cup of the coupler shaft mounts to the "front" of the crossmember, the bolts passing through the crossmember and holding both the rear axle cup and clamshells and front trumpet cup together pinching the crossmember between.

The problem is with the engine in place you can't get enough "telescope" in the coupler shaft to install it alone (it does telescope fractionally to allow movement of the frame/engine.)

So you'll have to remove the engine.

On my AA truck I explored the possibility of installing a Ruxstell overdrive - but the ruxstell was a device originated during the 3 speed transmission truck era. It was possible to put the ruxstell in, but one had to revert to the early truck method given by SeaSlugs above. A diamond shaped intermediate receiver (that bolts to the mid crossmember and holds the dual high or ruxtell from turning) was the issue.

Hope this helps.

Joe K

[Bob C]

Here are some pictures of the original coupling shafts, not the service replacement.
Notice that the coupler bell cover comes in from the rear of the cross member were as the one on the service replacement goes on the front side of the cross member. The one on the left is used with the 3-speed trans and the right one is for the 4-speed.

Bob

[Joe K]

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Heh. Looking at your "left" diagram and your earlier "replacement" they appear to be the same parts but applied differently.

I can see how this might be. The internal gear - shaft - universal joint distance will stay the same but the exterior housing at both ends has "free play" where the housings can slip on the tube - one could install the "left" version parts but do it as your "replacement" diagram?

Mine was done per the replacement - it was an original 1930 late truck with 26K miles on it. At least part of the challenge of putting the ruxtell in was the rear crossmember mount location of the diamond receiver.

Truck chassis now gone to a buyer living in Texas.

Joe K

[Bob C]

The Service Replacement didn't come out until mid 1932.

Bob