If you want to start a spirited discussion at any cruise night, just ask a bunch of guys which is better, an automatic or a bang-your-own transmission. The resulting conversation will ensue for quite some time. Now, take the guys from the manual camp, and let them discuss putting a five speed in their car—and the discussion continues.
The installation of an aftermarket five speed transmission has always required some cutting and modification—until now. Let’s face it, the aftermarket offerings were quite a bit larger, and we don’t know of any E-, B-, or A-Body that was factory designed to accept a “late-model” transmission. Now however, all of that has changed. After a couple of years of developmental work, Passon Performance has come up with an all-new, made in the USA transmission, that gives you five gears, and fits your Mopar—without any cutting or modifications. We first introduced you to the Passon 855 transmission in our May 2011 issue, but since the production versions are finally shipping (as of this writing), we wanted to let you guys know what to expect when you get to install yours.
Before you put it in your car though, we’re sure that you have a couple of questions, like “What gearing is available”? The factory 18-spline transmission came with a couple of different gearings, but for comparison in this article, we’ll focus on the unit that came in 1966-1970 vehicles. First gear was a 2.65, second gear was 1.93, third gear was 1.39, and fourth gear was 1.00. Keeping a good ratio spread between gears, the Passon five-speed gives you a 2.65 first gear, a 1.92 second gear, 1.40 third gear, a 1.00 fourth gear, and a final overdrive ratio of .70. So, you can stick this thing in your 4.10 rear-geared Mopar and go cruising.
If you want to know how strong it is, the case is made from virgin 356 aluminum alloy, the gears and shafts are made from US-origin aerospace alloys, such as 9310, along with other components made from US-origin bearing quality material. Have you noticed the US consistency yet? A key piece, the counter shaft, starts out as one piece of 9310, with all counter shaft gears integral to the shaft. According to Jamie, “This style of producing the counter shaft gives us maximum bending resistance when compared to counter shafts made from several components.”
Tapered roller bearings can be found on the main shaft, input shaft, and counter shaft, which are necessary to absorb the axial thrust developed by the helical gear sets. At the 700-lb/ft. power level, we are developing about 30-percent less axial thrust than other five speed manufacturers. This means less power robbing frictional heat is being developed, and more power is delivered to the rear wheels.
In addition, caged-needle roller bearings are located under the speed gears, and a caged roller bearing is at the main shaft’s input shaft location. A Torrington style thrust bearing keeps the relationship between the main shaft and input shaft at the proper location and preload.
Shift function is controlled by bearing quality bronze forks, riding on an internal guide rail that insures positive shifts. There is no fork twist that can happen with the single post style forks found in an original-design stock transmission. Shift control-shafts are mounted in dual needle bearings.
The T-6 hardened aluminum case is machined in Central Pennsylvania, by shops specializing in transmission housing manufacturing. Final machined case strength is well over their stated power-handling capability.
Jamie finished with, “Our design team was given the challenge of designing a transmission that would fit in the original location, without modification to the car. It also had to be able to handle the massive power produced by today’s big-inch engines, like the 572 Hemi. There is no other transmission that will do those jobs, and also have the bonus of a “period correct look” in a single package, except the A-855.
Since Jamie is adamant that this transmission is a true bolt-in design—and since we’ve heard that before, we wanted to see if he would put his money where his mouth is, and made him come to our shop to help with the install. We didn’t have him come to us because we wanted someone to do the work, but because we wanted him close, just in case we had to feed him his crow if it didn’t fit. Jamie was confident enough, that he did come and help with the install, and he even came with a full stomach.
Cost for Passon A-855 Transmission:
*Kit includes: Transmission, Shifter mechanism and linkage, new speedometer cable