Disc Brakes and Gearboxes . . .
In the very early '50s Chrysler offered a brake manufactured by a supplier named Ausco under the patent of an engineer named Lambert. It used two discs with friction material contained inside a cast-iron drum, with the discs connected to a ball-bearing and ramp mechanism which pushed them out into the inner sides of the drum. It isn't a modern disc brake by a long shot, which uses stationary pads on each side of a rotating disc that grab the disc when hydraulic pressure is applied. The Ausco-Lambert brake was a very rare option on Chryslers for a few years and then was discontinued due to problems. Most of the Ausco-Lambert equipped cars were converted back to conventional drum brakes. I have been told by the owner of an Ausco-Lambert equipped car that the brakes can be made to work reliably and adequately by modifications to the ball bearing actuation system, but the originals tended to suffer severe corrosion problems. One odd characteristic of the Ausco-Lambert design is that it was self-energizing, like drum brakes, which means that as the brake is applied it gets progressively easier to apply, leading to grabbiness under some conditions. One of the big advantages of modern disc brakes is that they don't self-energize and so are easier to modulate in panic stops than drums. Chrysler didn't care to spend any money or time developing the system, nor did they bother to develop an alternate, modern disc brake system - I believe it wasn’t until the mid ‘60s that they offered a modern disc brake.
Crosley’s disc brake was more of a modern, conventional disc brake. It was a real pioneering effort but like Chrysler’s didn’t work well in service and was discontinued. With decent financing, Crosley could probably have done better as their design was basically sound. The first successful modern disc brake shown to the public was created by Dunlop in England. It allowed the Jaguar C-Type racing car to outbrake all the competition at LeMans in ’53, although it wouldn’t be offered on a Jag street car until ’57. Jensen supposedly put these brakes on a couple of cars in ’54 as a test, but the first official offering was on the Austin-Healey 100S of ’55. This was a very special option package designed for owners who were going to race the cars, with about 50 examples built. All the other Austin-Healeys made do with drums until the late ‘50s.
The first mass-produced car to offer modern, reliable disc brakes was the Citroen DS19, which was introduced in the fall of ’55 and went into immediate mass production with standard front discs. A slightly cheaper variant, the ID19, appeared the next year but still with the standard disc brakes. These disc brakes had to be successful, as the D-series cars were never offered with any type of drum brake for the front wheels. The brakes were designed and manufactured by Citroen and featured two hydraulic cylinders on one side of a sliding caliper, and an integral self adjusting mechanical parking brake. They were used through the ’65 model year and into ’66, at which point they were replaced with an improved design. Except for very early (pre ’62) ID19s, these brakes were actuated by a true high pressure power system with no master cylinder.
With regard to automatics, the original Hydramatic was a four speed gearbox, but not in the modern sense. First was basically a granny gear designed to just get the car moving at which point it shifted into second. Once underway it operated more like a three speed. The granny gear was a byproduct of using a fluid coupling rather than a torque converter; the fluid coupling is more efficient but doesn’t help much in moving the car from rest, so the granny first was needed. Some owners didn’t like the immediate shift into second as it could create a small clunk and jerk – some Hydramatic versions are smoother here than others.
Chrysler really changed the game in late ’56 when the Torqueflite was introduced, with three speeds and a torque converter. It was smoother and quieter than any automatic before. By the mid-‘60s GM abandoned the old fluid coupling Hydramatic in favor of the Turbohydramatic which featured three speeds and a torque converter. Ford had already gone this route with the Cruise-O-Matic, and by the early ‘70s even Mercedes did the same thing, abandoning their old four speed plus fluid coupling Hydramatic clone in favor of three speeds plus a torque converter. I’m not arguing that three speeds are better than four, it’s just that the Hydramatic didn’t have four really useful gears. BTW, lockup torque converters did exist in the ‘50s – both Packard and Borg-Warner used them.
[this post was last edited: 10/15/2010-16:39]
