So you've been thinking about putting a five-speed manual transmission in your Mopar for quite a while. Your only concern is that you don't want to modify your floor in your car. That's been the hold-up for a lot of guys, as with any of the current five-speed retrofits, the Tremec TKO that is used, requires some sort of modification to your car. What if we told you that is no longer a problem? What if we told you that you can have a completely new five-speed transmission that bolts in place of the factory Mopar four-speed-without cutting your car? Well, it's now a reality thanks to Passon Performance.
For the past 15 years, Passon Performance has been known for rebuilding top-notch Chrysler four-speed transmissions. Not only do they rebuild them, but over the years, they have developed more innovations for the A-833 four-speed than just about anyone else. Now, they have done it again with their all-new five-speed transmission. According to Jamie at Passon Performance, "This is the only five-speed transmission on the market that is a direct bolt-in replacement for the A-833 four-speed. There have been numerous "off the shelf" five-speed transmissions that have been used by various companies to make up kits to retrofit these modern transmissions into early Chrysler muscle cars, but all of these have one thing in common: They do not fit. They all require either cutting the floorpan or adversely changing the driveline angle of the vehicle. In some instances, these kits even require cutting into the structural torsion bar crossmember. Not to mention you must modify or change things like the clutch, bellhousing, driveshaft, shifter handles, and/or clutch linkages."
If you're going to swap your...
If you're going to swap your Mopar's four-speed to a five-speed, you don't want to have to worry about locating a bunch of parts to do the swap. So Passon made the output shaft the same as Mopar's 833. This means your factory driveshaft will work. Also note the shifter location and styles. When installed, your shifter handle will be located in the factory spot.
When Jamie told us about this all-new transmission he has designed and developed with GFI (their partner on the project) we had to take a look for ourselves. Our biggest question was, will it fit? With the Chrysler 833 and the new Passon five-speed setting side-by-side, it's fairly hard to argue that point. Now, keep in mind that while this is a bolt-in unit, you will need an 18-spline clutch disc. OK, OK, so you'll have to change the clutch disc if you're running a 23-spline 833, but the 18-spline was offered from Mopar in the 833, because it was stronger, so why wouldn't Passon's do the same thing. Speaking of fitment, the all-new five-bolt bearing retainer is available in 4.35-inch and 4.80-inch diameters for nearly all stock-dimension bellhousings. Adapter rings are available where necessary for aftermarket or special bellhousing needs. As far as your driveshaft, keep the one you have. Your factory driveshaft from your four-speed car will go right back in. Now, this transmission is a five-speed, so that means that you need a new shifter, right? Well, the shifter and all linkage rods are shipped with the transmission. All you will need to do is install your handle on the new Hurst Competition Plus shifter.
How strong is this thing? Jamie tells us "the case is cast from 356 T6 aluminum alloy that is heat treated for strength, all gears and the main shaft are made of Aircraft Quality 9310 alloy steel. Not only are quality materials used on the case, all forward gears feature caged roller bearings for reduced friction, tapered roller bearings for the main and countershaft, and double needle-type roller bearings are used on the gear selector shafts for ultra-smooth operation." Another "upgrade" if you will from the factory transmission construction, is the use of O-ring seals between all case components instead of the old paper style pieces, ensuring a leak-free case.
When it comes to gearing, the factory 18-spline transmission came with a couple of different gearings, but for this article, we'll focus on the unit that came in '66-'70 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.
When we first saw the transmission, Jamie told us that they are looking for a late-Spring release on this product. Also, the A-Body case was the only one we could take a look at, but Jamie says the B- and E-Body tailhousings are not far behind. By the time you read this, we hope to have a unit installed in a car, and abused to within an inch of its life, so we'll let you know how and if it really bolts in, and if it can live up to the tough reputation of the 833.
In this shot you can see the...
In this shot you can see the comparable size and dimensions of the Passon five-speed to the Mopar 833.
No special bellhousing is...
No special bellhousing is required; the Passon five-speed will fit a stock Mopar bellhousing. Just let Passon know if yours has a 4.35-inch or a 4.80-inch diameter opening for the bearing retainer.
By building a transmission...
By building a transmission utilizing external linkage, the install is as basic as a stock replacement. If you're wondering how Passon gets away with only using three linkage rods for five gears, a lot of thought and design went into making the reverse/fifth-gear rod work.
Building a unit like this...
Building a unit like this in the 21st Century means that since better assembly procedures are now available over mid-'60s designs, you might as well use them. To that end, all case-seams are sealed by silicone O-rings to ensure no leakage as opposed to O.E cases.
Just to show you the lengths...
Just to show you the lengths that Passon went to ensure interchangeability, the speedometer gear connection is all Mopar.
When it comes to the gears,...
When it comes to the gears, there wasn't much that could be utilized from an existing transmission, sao Passon's had to design and develop their own. All gears-and the main-shaft are made of aircraft quality 9310 alloy steel.