1969 Road Runner Project, Part VI

We were in a quandary. Ken Lazzeri’s SuperFlow dyno had just pegged 700 lb/ft of torque with the Holley Project Roadrunner 542ci RB engine. While we were very excited about the brute force of the engine, we were haunted with the thought of trying to harness that power and route it in a dignified fashion to the pavement. Ken asked, "So what are you going to do for a transmission?" We answered, "An 833 manual." "Hmmm," Ken groaned. "An automatic would be better." It wasn’t the first time someone had said that, but what’s a Roadrunner if you can’t bang the gears? The Holley Project Roadrunner was to be a true Hemi Orange muscle car, right down to the four-speed. Now I was thinking more like Ken. With all that torque and streetability an issue, I began considering more than the power of the engine, but the driveability and durability concerns.

Fortunately, Ken Hensley of Hensley Enterprises was standing nearby. "You know, McCandless could build you up a great 18-spline Hemi four-speed with all-new parts." "He could?" we asked. Little did we know that Herb and Hensley were in town to test a small-block combination and about that time Herb walked in. Ken mentioned a bet that someone had made with Herb--a bet where Herb insisted he could build an A833 four-speed with a blindfold on. As Herb related the story in a manner that was more humorous than technical, it became apparent that either the stakes were too high or the contestant was too well aware of Herb’s prowess around Mopar’s A833 manual transmission. So with the pieces in place and Herb’s willingness, we asked Herb to build and document the assembly (with the assistance of his son David) of a brute-force, 18-spline Hemi 4-speed. Once you’ve seen what is shown here, you’ll recognize that the best bet is always on Herb McCandless.

Herb McCandless on the A833
The 18-spline Chrysler 4-speed is by far the strongest 4-speed ever used in production cars. It is also the easiest 4-speed to work on. Parts are hard to find only because these transmissions rarely broke, so very few replacement parts were made. Liberty Gear in Michigan is able to save many of our A833 gears. They can repair the pilot of the input that goes into the crank. Liberty can also put new clutching teeth back on the gears and they have many parts for these transmissions. The parts necessary to make these transmissions shift and work properly are still readily available. The problem with transmission shifting 90 percent of the time is in the clutch or clutch linkage. If you have a high-powered car, the new dual disc clutches such as the McLeod Street Twin are the only way to go.

The Clinic Begins

1. The sharper the clutching teeth on the gears and the synchronizer assemblies, the better the car will shift.

2. If you are going to build a Chrysler 4-speed, you need to start with a nice, clean work area. Clean all the parts and get them ready for assembly.

3. I like to see new needle bearings in the cluster and input shaft, and a new shaft pin for the cluster if yours shows any wear.

4. I use a thick grease such as Valvoline semi synthetic Dura Blend grease. Put the spacer in the cluster, then pack a row of needle bearings, then a washer, another row of needles, and another washer. Turn the cluster around and do the same to the other end. Take the large copper-faced washer that goes between the case and cluster, put grease on it and stick the washer to the front of the case. Now slide the cluster into the case and lay it down into the case. Pack the needle bearings into the input shaft and install the front bearing.

5. It is very important, if your case is a large bearing number 308, to purchase your 308 bearing from either a Mopar Performance or Chrysler dealer. Many parts houses list the wrong bearing for these transmissions--the inside and outside diameters are correct but they are .030 too thin. If you have large bearings front and rear you will have .060 slack in the transmission that does not belong there. This could cause problems.

6. With your front bearing on the input and the snap ring in place, put the input into the case. We are now ready to lift our cluster into place and slip the new rear copper-coated cluster washer into place (photo 3). Slide the cluster pin into the case through the cluster. Tap the pin slowly into the case (photo 5), and insert the key to keep the shaft from turning just before the pin goes flush with the case.

7. If you have the reverse assemby out of the case, put a new O-ring on the shifting arm and install the reverse into the case. Next, prepare the tailhousing. Install a new bushing for the driveshaft slip yoke to run on. This bushing is readily available as it is the same bushing as the 727 automatic.

8. Then, install the splash shield (photo 4) to prevent oil from coming out of the breather. Prepare the front bearing retainer by installing a new seal, and put a small amount of oil on the seal. Do not put the seal on the shaft dry.

9. Take the main shaft and install Second gear on the shaft, followed by the 1-2 synchronizer assembly, large snap ring, low gear, rear bearing, then small snap ring. If your transmission has the 308 rear bearing, the large snap ring that holds the bearing in place goes into the tailhousing. If it has the 307 bearing, the snap ring goes between the low gear and the rear bearing. The 308 rear bearings go on with the snap ring groove to the front.

10. We now go to the front of the shaft, install Third gear and 3-4 synchronizer assembly and snap ring to hold the assembly in place. When installing the synchronizer assemblies, the shift fork grooves go towards each other. Installing the new brass rings into the synchronizer assemblies makes them shift much better. Try to use the late-model synchronizer assemblies. The early model brass rings from Mopar Performance are made incorrectly--the slots are cut. 060-inch too deep and do not flt.

11. It is time to slip the main shaft into the tailhousing. The 308 bearing is very easy to install. Simply spread the snap ring in the tailhousing and slide the bearing and main shaft into the housing. If it is a 307 bearing, it is a little more difficult. The bearing goes into the housing and you must compress the snap ring and follow the bearing into the housing. Channellock makes a pair of pliers that makes the job much easier, (number #748).

12. Next, lay the case on its side and put a 2x4 block of wood under the rear of the case so it will hold the back of the case up off the table. Stick your gasket to the tailhousing case.

13. Slip the input shaft as far forward as you can, about 1/8-inch. Now slide the 3-4 slider forward almost halfway, but do not let the 3 dogs come out of the assembly. Take the tailhousing assembly and slip it into the case. Go slow, being careful not to dislodge the needle bearings. Have someone slowly turn the input as you go together with all the gears.

14. Now slip the 3-4 slider back into place. Turn the input until the brass rings and synchronizer assembly line up. Slip the input back into the case.

15. Bolt the tailhousing to the case, and install the gasket on the front bearing retainer. Bolt to the case, making sure the oil hole in the case and the return notch in the front retainer line up.

16. Put new O-rings on the shifting arms and install them in the side cover. Make sure the sleeve, spring, pin, and the 2 balls are in good shape.

17. If you have 2 good brass forks, use them. You can put the late-model steel forks in the earlier side cover by cutting the small end off the steel fork.

18. Stick the gasket to the side cover or case.

19. Slip the forks into synchronizer assemblies. Now set the cover on the case and put the forks into the side cover. I like to have transmission in reverse when I install the side cover.

20. On most Chrysler 4 speeds, the center rear-side cover bolt is a line-up bolt. It has a longer shoulder that goes into the case to locate the side cover on the case. These transmissions are very simple to build.