If you are observant, you will notice that most of the specialty race sets use the 23-spline input shaft. The way I understand it, in order to adhere to the “factory equipment regulations” the 23-spline input must be used instead of the 18-spline. It is for this reason that Chrysler actually made input shafts that were 23–clutch splines, but had a 21-tooth gear on the inside of the transmission case that was the same as an assembly line 18-spline transmission. These gears were all 9310 material. They were identified by S K numbers. To date, I have not found out the actual reasoning for these S K numbers; however, the number is present on these gears.
The red-stripe drag gears had unfinished synchronizer cones and every other synchronizer tooth was missing. This brought the number down from 36 to 18 teeth. The synchronizer slider was modified to remove every other internal spline to match the gears. This also brought the number down from 36 to 18 splines. These were meant for use in an unsynchronized racing situation. The gears typically had a short life, but were plentiful, so they were simply replaced. Chrysler made the white-stripe gears like this as well. These gears are identical to the assembly line white-stripe gears except for the synchronizer tooth arrangement, which was the same as the red-stripe drag gears. These gears are commonly referred to as “slick shift” gears. This was the preferred setup for drag racing versus a stock synchronizer setup. A solid inner hub was used with this arrangement even though a stock slotted hub could be used by removing the strut keys and synchronizer springs.
NOTES:
1: The cluster gear is identified by one thin hash mark machined in the barrel area. Speed gears have a thin hash mark machined on the outer edge of the gear teeth on the second and third gears. The input shaft has a slightly wider hash machined at the base of the pilot tip. This will interchange with the 1977 and Up OD input shaft.
2: The cluster gear is identified by two hash marks machined in the barrel area. The first, second, and third gears are oilite bushed and have no hash marks.
3: The cluster gear is identified by three hash marks machined in the barrel area. The outer edges of the second and third gears have three hashes machined in them.
4: The cluster gear is identified by six hash marks that are machined in the barrel area. The first, second, and third gears are oilite bushed. The second and third gears have two hash marks machined into the outer edges of the teeth. Be careful not to mix these up. The two-hash-mark speed gears do not match the two-hash-mark cluster gear.
5: All speed gears have a wide hash mark machined in the outer edge of the teeth. The cluster gear also has a single wide hash mark machined in the barrel area. This is known as the “high helix” OD ratio.
6: All speed gears have a single wide hash mark machined into the outer edge of the speed gears. The cluster gear has a wide hash mark machined into the barrel area of the cluster. This gear is recognizable when compared to the 1964–1965 A-Body because of the much larger third gear row of teeth.
7: First gear interchanges.
8: First gear interchanges.
Once things started to evolve, aftermarket companies modified factory gears and made replacement gears for the A-833. Liberty’s Gears in Michigan designed a synchronizer setup known as “Pro shift.” This setup actually removed all of the factory synchronizer teeth and replaced them with a hardened ring that was welded to the gear. This ring had 12 larger lugs on it. You could use a factory slider that was modified by removing two splines and then leaving one. This system was a significant upgrade to the slick shift setup for two reasons. It shifted better and the gears could be rebuilt. When the lugs were damaged, the ring was cut off and a new one was welded on. Liberty’s also made additional first-gear ratios for the 18-spline transmission, including a 2.93:1 first gear ratio. These gears were not made in the stock configuration.
You will notice, if you look closely, the difference between some of the clutch splines and also the identification markings on the drive teeth in these seven stock factory gear ratio input shafts.
Doug Nash had a similar arrangement as the Pro shift. These pieces could be interchanged. Another company named G.E.R. also made gears for the A-833. They had a similar setup, except that it had 10 lugs instead of 12. It also required the use of G.E.R. hubs, whereas Liberty’s and Doug Nash used a stock configuration hub. ■
Again, close inspection reveals identification grooves that are machined in the barrel area of the gear. This allowed quick identification between the seven different assembly line ration cluster gears.
CHAPTER 2
FUNCTION OF THE A-833
The A-833 4-speed, like practically all muscle car–era 4-speed transmissions, is what is known as a constant mesh transmission. This simply means that all forward gears are in constant contact with the cluster gear in the case at all times. Even in reverse, the forward gears are in mesh, but since none of them are locked to the mainshaft while the unit is in reverse, the direction of gear travel can be reversed without damage.
Let’s begin by reviewing terminology. There are several terms that are used regarding the components of the A-833 transmission, as described in the image here.
A synchronizer is made up of several components. In addition, there were three different main designs as described in Chapter 1.
“A” is the synchronizer clutch gear. This is also known as a synchronizer hub. This is the part that attaches to the mainshaft via splines and is retained by a snap ring. The splines around the outer circumference match the splines on the inside of component B.“B” is the clutch sleeve. This is also known as a synchronizer slider. This, too, is splined on the inside, which mates with the outer splines of component A.“C” shows the three strut keys. These are sometimes called “dogs” or “shift struts.” They are retained in a slot in component A and held in by component B.“D” shows two strut key springs. These provide outward pressure to stabilize and retain the components in C.“E” is a synchronizer stop ring. Sometimes called synchronizer rings, these are sandwiched between the synchronizer assembly and the gear cone.
General operation of a synchronizer during a gear change starts at the shifter handle. Movement of the handle transfers to the synchronizer via rods, levers, shafts, shift forks, sliders, strut keys, and synchronizer stop ring to the appropriate gear.
While first through fourth gears are fully synchronized in the A-833, reverse is not. This makes it necessary to be fully stopped before attempting to engage reverse. Otherwise, a “grind” will occur. This is not the case with putting the vehicle into first gear; you can be rolling forward slowly and put it in first gear and it typically will not grind. This is because the 1-2 synchronizer is engaged when the shift fork moves the clutch sleeve.
During a shift, the shift fork moves the slider. The slider is splined to the inner hub. Keep in mind that the inner hub is splined to the mainshaft. Therefore, the synchronizer assemblies always spin at mainshaft speed. Continuing on, the slider moves the three spring-loaded strut keys, which move the brass synchronizer stop ring onto the gear cone. As pressure is applied to the stop ring via the strut keys, the ring matches the speed of the gear to the speed of the mainshaft. This entire action is a “synchronized shift” and happens as quickly as you move your hand.
Power Flow and Layout