AA truck under drive auxiliary transmission

[sturgis 39]

I have everything loose on the transmission but I can not pull it off the drive shaft. I posted pictures on the v8 site for mercury overdrive. There must be a key or something that is holding it from sliding forward. I would post the pictures here except I have dial up and it took about two hours to post on the ev8 site. The grand daughter may miss a call from her boyfriend in that two hour time period.

 

[Tom Wesenberg]

Someone didn't believe in grease on this 1930 AA and even though I got this U-joint to move back and forth 1/2" with a lot of hammer blows, it took an extreme amount of heat to get it to slide off the splines.

If your splines have been greased then it should slide right off.

 

[Neil Wilson]

The optional AA dual high transmission or standard AA coupling shaft has the rear u-joint (i.e. u-joint at the drive shaft) bolted to the dual high or coupling shaft. So, the rear axle must be moved back resulting in the drive shaft pulling out of the u-joint. Then the u-joint can be unbolted from the dual high transmission so that it can be removed.

 

[sangar29]

You have probably been told this already but in case you havent been told, the rear end has to be losened and backed off far enuf the get a 3/8th socket inside the UJ and unscrew the UJ bolt, then the 2 or 3 speed transmision or jack shaft can be removed.

 

[sturgis 39]

The optional AA dual high transmission or standard AA coupling shaft has the rear u-joint (i.e. u-joint at the drive shaft) bolted to the dual high or coupling shaft. So, the rear axle must be moved back resulting in the drive shaft pulling out of the u-joint. Then the u-joint can be unbolted from the dual high transmission so that it can be removed.

Why do they call the transmission a dual high? The way I understand is the high on the auxiliary transmission is a direct drive ( 1 to 1 ratio). When you shift the axillary to the other position it is an under drive and lowers the rpm output to the rear end. Is this correct?

 

[Chris Haynes]

Why do they call the transmission a dual high? The way I understand is the high on the auxiliary transmission is a direct drive ( 1 to 1 ratio). When you shift the axillary to the other position it is an under drive and lowers the rpm output to the rear end. Is this correct?

That is correct. Dual High is strictly Ford sales terminology. You do have dual high gears. High gear being third gear. One in under drive and the other in direct.

 

[sturgis 39]

That is correct. Dual High is strictly Ford sales terminology. You do have dual high gears. High gear being third gear. One in under drive and the other in direct.

Thanks for the reply.I never drove a "AA" truck. My dad had one and it had the axillary transmission. It was his work horse. He used it for hauling water, hauling fire wood, running the buzz saw and building a cabin. i remember him installing a different model "A" engine and changing and fixing tires. It had the split rims. I was pretty sure that was how he explained the Aux transmission. He died in 1957. It is funny the things you remember from your childhood.

Thanks again