The Ford Barn

Railcarmover · 10-09-2018, 08:25 AM

Gee,and here I was thinking the u joint slides on splines on the driveshaft...and since its not Hotchkiss drive,the entire rear axle assembly pivots at the 'clamshell'..the splines at the driveshaft/u joint coupling allow for any thrust force to be tolerated.

Sparky · 10-10-2018, 08:42 AM

Quote:

Originally Posted by nosoup4u

Just guessing that the driveshaft is 60" and the frame is 12" above the driveshaft. The rear axle moving up 4" would change the driveshaft only about an inch.
Thanks to the PT calculators on the internet because I slept through geometry class.

If the axle moved straight up 4" the length change would be only about 1/8 inch, easily taken up by the spring shackles.

Jim Brierley · 10-10-2018, 11:28 AM

The diff itself can and does move up and down quite a bit, in an arc. The drive shaft/torque tube length does not change. A lot of good answers here, along with a lot of misunderstandings. Actually the diff does not move up or down, the car frame and body move, depending on how many fat broads are in the back seat.

10-09-2018, 08:25 AM	#21
Railcarmover BANNED Join Date: Apr 2017 Location: Sacramento Posts: 1,262	Re: Model A rear axle and the Pythagorean theorem Gee,and here I was thinking the u joint slides on splines on the driveshaft...and since its not Hotchkiss drive,the entire rear axle assembly pivots at the 'clamshell'..the splines at the driveshaft/u joint coupling allow for any thrust force to be tolerated.

10-10-2018, 11:28 AM	#23
Jim Brierley Senior Member Join Date: Jun 2010 Location: Temecula, CA Posts: 4,087	Re: Model A rear axle and the Pythagorean theorem The diff itself can and does move up and down quite a bit, in an arc. The drive shaft/torque tube length does not change. A lot of good answers here, along with a lot of misunderstandings. Actually the diff does not move up or down, the car frame and body move, depending on how many fat broads are in the back seat.