Twin Traction Trivia

'56 Packard was first to have it (so it was a Packard invention, but as part of Studebaker-Packard). Paul Johnson

"In 1932 Ferdinand Porsche designed a Grand Prix racing car for the Auto Union company. The high power of the design caused one of the rear wheels to experience excessive wheel spin at any speed up to 100 MPH. In

1935 Porsche commissioned the engineering firm ZF to design an Limited slip differential which performed very well."

Spicer/Dana "invented" the Twin Traction style rear used by Studebaker, Chrysler and other in 58.

Jeff DeWitt wrote:

SAE has the Packard technical paper about the limited slip rear:

Title: The Packard non-spinning differential Document Number: 560247

Author(s): Forest McFarland - Advanced Engrg. Div., Studebaker-Packard Corp. E. L. Nash - Advanced Engrg. Div., Studebaker-Packard Corp.

The paper is dated Jan. 1, 1956. I think Twin Traction was available in '57, on Studes.

Mike M.

I had heard it was on the 1956 Packard that the first TT was available. I will check my 56 Executive and see if it is with a TT.

Twin Traction was first available on 1956 Packards and 1956 Studebaker half ton pickups. It was the 1957 model year when TT was available on Studebaker cars.

Found this patent from July 12, 1954.

2769353 "DIFFERENTIAL GEARING - Edward L. Nash"

"The present application relates to differential gearing for driving appositely extending axle members and particularly relates to differential gearing having clutch members effective between the axle members to equalize the speeds for the latter when one axle becomes relatively unloaded and tends to overrun the other excessively."