We built a replacement Ruckstell axle for our Model T a couple years ago. See the articles here: https://modeltfordfix.com/the-ruckstell-two-speed-axle/
Finally the time has come to install it. The Ruckstell axle in the car worked fine, it has the standard 3.63:1 gear ratio. The axle being installed has the optional Ruckstell ratio of 3.25:1.
With the rear axle installed we filled the Ruckstell with SAE 85W-140 rear end lubricant and removed the jack stands. A drive around the neighborhood confirmed the newly rebuilt Ruckstell axle was quiet and performed well.