Drive Train
40-spline axles in a Dana differential...Gearbox
 |
The Rodeo currently runs a tricked-up 2-speed
powerglide. Our friendly local automatic transmission guru tells us
that these things can be made indestructible; it all depends on how much
money you wish to throw at 'em. This particular unit has a set of
straight-cut gears, whilst another unit has a better drum. One of
these days I'll have to figure out exactly what he's talking about... :)
The anodised unit behind the powerglide, is a reduction box. The car also has a second reduction box in front of the powerglide. This allows for an almost infinitely variable combination of gear ratios for various courses. The rear of this reduction box can be easily removed during a race to allow for quick gear ratio modifications. Gear sets are relatively cheap (about $100 a set), but they're not particularly tough and do wear out relatively quickly. Note that the front/rear reduction boxes run in gear-oil, whilst the powerglide obviously runs auto-tranny fluid. Also note the alternator pulley on the output shaft of the reduction box. This has been removed and the alternator now resides next to the supercharger. |
Reductions Boxes
 |
Pictured is the rear of the motor, including front
reduction box (all the anodised blue ally), the flywheel and ring-gear, and
the flex-plate (bolts up to the torque converter). A. Flex-plate, B. front reduction box, C. Starter motor, D. Counter-shaft drive from front of motor (used to drive power steering and dry-sump pumps), E. Power steering pumps, F. Dry-sump pumps, G. Flywheel, H. Jez's hand. |
 |
Pictured is the front reduction box (item B in
picture above). Access to this unit (and the gears within) is more
complicated than the rear reduction box and as such it tends to run on a
particular set of gears constantly.
A. Front reduction box, B. Flex-plate, C. Rattle box, D. Flywheel and ring-gear. Note the rattle box is a simple dog-gear that transfers drive between the engine and front reduction box, without a long spline or the need for bolts. The more it wears, the more it rattles, and it is quite noisy (especially at idle). |
Axles and Hubs
 |
The floating hubs do not rely on the axle and are
located on the differential by internal/external tapered bearings.
This means the axle can shear without losing the wheel/hub combination.
A. The 40-spline hollow axles that the Rodeo runs. Because the actual spline size doesn't alter, the difference between a 28-spline axle and 40-spline axle is simply one of diameter (the 40 being bigger). They are hollow because most torsional load is absorbed by the outside of the shaft, and the weight-reduction more than offsets the loss of torsional loading provided by metal at the centre of the shaft. B. CNC 4-spot calliper, C. Ventilated disc, D. Floating hub, E. Wheel stud. |
