Image Discuss: Plan View of 27's Transmissions

[PMGRACER]

Good guess. Planetary gear sets may have more resistance than spur gearing, but you are able to have higher changes in ratio in a smaller space. There are some really cool trannies out this year. Many different approaches. I can't wait to see them all at the regionals and Houston.

I'm glad we finally went to pnuematics to shift. This new setup shifts quickly, and reliably. We never did have to much luck with servo-actuation last year.

The trans uses a slider ring similar in design to the Bosch ring, but made out of mild steel. I had the Chrysler machine shop EDM the teeth into the center, then I cut a 1.625 hex into the face which engages on the face of the housing. We designed the shift fork to use 4-48 thread allen heads turned down on the ends to .08 which ride in a .084 groove in the shift ring. The pins are spaced 120 degrees apart and suspend the shift ring on centerline. We are using the 1/2" stoke Bimba cylinders for shift actuation. One other item we had to address was the radial load the drivetrain applied to the output. So we are now using .500 Timken Tappered roller bearings to keep the shaft from wearing out the gearset.
PMGRACER