Begin by draining the oil...
Begin by draining the oil and removing the shifter and linkage and the driveshaft.
It all started in October 2002, when I drove the Valiant to Bristol, Tennessee. In case you're counting, that's a lot of miles with the little 360 dutifully holding the tach needle at 3,500 rpm. The trip was fun, with the radio faintly jamming under the screaming engine.
Somewhere around Atlanta, Georgia, I decided something needed to be done. I got to thinking (Since the cotton in my ears kept things from leaking out, I had no better use for the old noggin), How would a Gear Vendors unit work in this thing? The Gear Vendors unit offers a .78 to 1 (22 percent) overdrive ratio, and that will effectively reduce fuel consumption, engine rpm, and, oh yeah, a lot of noise from that rpm. Another option with GV is the ability to split each shift. For example, you can start in First gear, then hit the GV button and have First high. You can then hit the button and shift to Second after the rpm has reached the point of shifting, and then hit the GV button. Theoretically, splitting each shift of the four-speed like this gives you eight speeds from a four-speed tranny. Rearend gearing affects the split-shift theory dramatically.
With the tranny on the bench...
With the tranny on the bench next to the GV intermediate housing, you can see the difference. You can also see how much longer the entire assembly is. We had Lakeland Driveshaft shorten and balance our driveshaft. For our application, the total length of the needed driveshaft is 31 inches from the universal joint, center-to-center.
I decided to take the plunge: I called Gear Vendors and told them what I needed, and about a week later, the box-o-goodies arrived. However, as soon as I opened the box, I hit my first glitch. The intermediate housing that connects the under/overdrive unit to the tranny was for a long-tailshaft B- and E-Body transmission. Gear Vendors said they use the longer tailshaft to get more clearance between the GV unit and the floor. It sounded logical, because due to drivetrain angles, the farther back the unit, the lower it becomes. The problem is the A-Body-transmission output shaft is shorter than the B- and E-Body shaft, necessitating a longer output shaft for the tranny. Also, the output-shaft bearing in the A-Body tailshaft housing is a 307 bearing, while the B- and E-body tailshaft housing uses a 308 bearing. To fix this minor glitch, I called Passon Performance in Sugar Loaf, Pennsylvania. If you decide to put a GV unit in your A-Body and you have a long-tailshaft B- or E-body tranny lying in the corner, problem solved.
GV is aware of the situation and is exploring possible remedies. By the time this story makes it to print, they will probably have the problem solved. I'm glad Jamie at Passon Performance didn't get upset with the numerous phone calls he received from me, as this was my first time tearing a four-speed tranny apart. After the service I received from Gear Vendors and Passon Performance, I highly recommend them both.
 Remove the side cover, exposing...  Remove the side cover, exposing the gears inside. |  Next, remove the six bolts...  Next, remove the six bolts holding the tailhousing on, and slide the housing and output-shaft assembly out of the tranny. Don't panic when the needle bearings in the input shaft fall out; just make sure you don't lose any of them. |  (A) After you pull the output...  (A) After you pull the output assembly out of the tranny, pinch the snap ring that holds the assembly into the tailshaft. The screwdriver points to the location of the snap ring behind the First-speed gear. (B) Pinch the snap ring, and pull the assembly out of the housing. |
 You need a pair of snap-ring...  You need a pair of snap-ring pliers to remove the three snap rings holding the gears on the shaft. The first snap ring (shown) comes off to allow the removal of the First-speed gear and the stop ring. |  |  After you remove the first...  After you remove the first snap ring, press the bearing off. As stated before, this bearing is changed to a larger 308 piece. |
 Now you can remove the First-speed...  Now you can remove the First-speed gear and the brass stop ring. Be careful to remember the direction of the gears so you can return them to the correct position. |  The second snap ring is now...  The second snap ring is now visible and should be removed. |  After removing the second...  After removing the second snap ring, the first and second clutch sleeve and the Second-speed gear can be removed. Make sure to keep everything in order, facing the correct way. |