Step 0: Take it apart

I'm starting out with a partially disassembeled transmission. So, to get caught up with my first step, you'll need to take yours apart. Open up the pan and remove the valve body and disconnect the front band. Remove the front pump with a slide hammer (the service manual shows where the threaded holes are). Take out all the clutches and gears. Remove the tailshaft yoke and tailshaft housing. One of the bottom bolts that holds on the tailshaft is also the pivot for the parking mechanism; the really long one. Don't pull this bolt all the way out yet, or you might lose some of the needle bearings the parking mechanism rides on. Remove the output shaft, but be careful not to lose the little ball bearing that engages the rear pump.

Step 1: Getting Started

Here's where I got started. All the little bits you see are styrofoam packing from when it was shipped to me in three boxes. There's also some pictures of individual pieces:
A couple pictures of the front of the case
Closeup picture of the front servo
Closeup picture of the rear servo
How most of the gears fit together
The output shaft and closeup of the governor
A couple pictures of all the internal pieces
From left to right you'll see in the front row: The output shaft, front drum and clutch pack, input shaft and rear clutch pack, front pump and reaction shaft
Back row: output shaft yoke, governor, rear pump housing, overrunning clutch, rear drum, planetary and annulus gear, driving shell, sun gear, front annulus and planetary gear.

You'll also want to remove the servos and accumulator. The front servo comes apart by removing the snap ring that holds the cover in the bore. The rear servo comes out basically the same way. The accumulator just pulls out. To get the accumulator and servo pistons out of the case, you should twist them while pulling to avoid scrathing the bores.

Last, remove the band linkages. The pivot for the front linkage comes out after you remove a threaded pipe plug from inside the bellhousing. The pivot for the rear band is accessable after you remove the tailshaft.

What's left is the empty case. Another pic from the front and from the bottom.


Setp 2: Clean everything

Now, you'll want to start with a completely clean table and a copy of the factory service manual. Use some kind of solvent to clean everything. Use rags to wipe off all the crud and varnish. Use Q-tips and pins to clean out all the little holes. Remove all the seal rings and clean the seats. Take the case to a car wash and clean it with the high-pressure sprayer.

Here's what I ended up with. I probably could have done better with a steam washer, but it's a lot better than it was. After the case it clean, you'll be able to see the cast-in part number on the passenger side, and the stampings on the driver side pan rail.


Step 3: Replace the Seals and Bushings

The rebuild kit will come with various rubber and metal seal rings and bushings. I didn't use all the rubber seals, so I'm assumming the others are for a 904 transmission. I did use all the metal seals, and all but one bushing. As you put things together, remember to lubricate everything you assemble with new, clean transmission fluid. Here's where all the bushings and seals go.

There will be 3 pairs of metal seals. two of them go on the reaction shaft These are the larger ones with the interlocking fingers on the ends.
Two more go on the governor assembly.
The last two rings go on the input shaft. These are the smaller ones with the interlocking fingers.

One of the bushings goes in the front drum. The other goes in the front pump. You'll probably want to take these to a machine shop to have the new bushings put in. Also, the service manual shows how to stake the pump bushing in place.

There are also two bushings inside the sun gear. The service manual says that it isn't cost effective to replace these bushings, and if the gear or bushings are worn, the whole thing should be replaced.

There's a seal on the front pump. Make sure it gets completely seated. For the tailshaft housing, put the bearing back in, its snap ring and the output shaft seal. The seal that comes in the kit is for '66 and later transmissions. You'll need to get one seperately.


Step 4: Front Clutch Pack

Before you start putting things back together, clean the work area again.

If you haven't taken it apart already, remove the top snap ring, pull out the pressure plate and all the clutches and steel plates. Compress the spring retainer with the tool I mentioned above and remove its snap ring. Pull out the spring retainer all the springs, and finally the piston. You can throw away the clutches and steel plates; new ones come in the kit.
Replace the inner rubber seal on the drum. Replace the seal on the outer edge of the piston, too.

Now, start to put it back together. Use lots of transmission fluid in the drum to help the piston seal get started in the bore. Install the piston into the drum. Be sure it's fully seated before you go to the next step.

Set the springs on the little fingers. Put the spring retainer back on and compress it until you can install the snap ring.

Note: Because of the way the piston and seals are situated, it's easy to fold or knick one of the seals when you install the piston into the drum. I ended up screwing it up on the first try and had to take it back apart and do it over. The service manual says to use Door Ease on the seals, a waxy product used to keep house doors from sticking or squeaking.

Now, put in the clutch disks alternating with steel plates, a pressure plate on the end, put the snap ring to lock it all in, and you end up with this. Be sure to measure the clearance between the pressure plate and snap ring to make sure it's within specs of what the service manual says.


Step 5: Rear Clutch Pack

If you haven't already, disassemble it by removing the snap ring and pressure plate, discarding all the clutches and steel disks, removing the next snap ring, piston spring and piston.

Replace the inner and outer rubber seals on the piston. Insert the piston into its bore. Put the spring in and secure it with its snap ring. Put in the first pressure plate, alternate clutches and steel disks. Put on the top pressure plate and secure with its snap ring. Measure the clearance between the pressure plate and snap ring.


Step 6: Front Pump

Turn the front pump cover over and set the front pump rotors in place. Make sure the oil holes in the reaction shaft support line up with the holes in the cover and bolt it down. Don't forget the sheet metal vent baffle.

Step 7: Output Shaft and Governor

Here are all the governor weights and generally how they go together. Basically, you put the small weight and pin in one end of the bore and the larger weights and spring go in the other end of the bore, and the snap rings hold everything together. Look in the service manual for a better diagram of how it all goes together.

The governor and parking gear then slip onto the output shaft. Start it from the end with the threaded extension. Be careful not to nick the speedometer gear teeth. The parking gear will engage the splined part of the shaft and stop at a machined shoulder. Put on the larger snap ring to hold it in place.


Step 8: Rear Pump

First, find the flat spot machined into the round part of the pump retainer. This will go up when installed into the case. Use a couple of bolts as guides so the oil passages line up, and knock it in using a hammer and a block of wood. Make sure it seats all the way.

Next, put the outer and inner pump rotors in place. Place the cover on top of everything and bolt it down. Make sure the cover is lined up the right way. Up is at the top of the picture.


Step 9: Install Servos

Front Servo

Here are the pieces for the front servo. The kit I have supplies a new inner spring (the blue one) to replace the spring that came out. All the parts go together like this. To install them in the case, first put in the piston, then the rod, then the inner and outer springs. Put the cover on top of the whole lot and use a clamp to compress the cover down enough to install the snap ring.

Rear Servo

Here are the parts for the rear servo. The kit came with a new outer spring, and said to ommit the smaller spring. The rubber seal around the piston get replaced. The small cup goes into the piston and is secured with the small snap ring. The piston goes into the bore followed by the large spring, the spring retainer, and then the snap ring.

Accumulator

For the accumulator, the kit said to ommit the spring. So, the accumulator piston just goes back into the bore.

A picture of the installed servos and accumulator.


Step 10: Overunning Clutch

The overunning clutch cam is inside the case at the rear. Place the overunning clutch inside the cam, then put all 12 rollers to the counterclockwise side of each of the little fingers on the cam, then put a spring between each finger and roller.

Step 11: Rear Band

The linkage generally goes together like this. It takes 3 or 4 hands, but if you hold the linkage in place then you can push the pivot through the hole in the rear of the case. Place the band in the case so the hooks can be grabbed by the fingers in the linkage. Don't forget the small stamped piece of metal that goes between the adjustable part of the linkage and the hook in the band. You can see it in the 7 o'clock position in this picture, and in the 4 o'clock position in this picture.

Step 12: Install the Gear Stack

First, install the rear drum. Ir should fit easily inside the rear band, and engage the splines in the overrunning clutch.

Next, I installed the output shaft. There is a 1/4" ball bearing that sits in a semi-drilled hole. The ball bearing engages a slot in the rear pump rotor. Line up the slot and ball, and fully seat the parking gear seal rings into the rear pump cover. Here, you can see the output shaft going through the rear drum.

Next comes the rear planetary and annulus gears. The annulus should engage the splines in the output shaft, and the lugs in the planetary should engage the slots in the rear drum. Another picture of the same thing.

The driving shell goes on next. Don't forget the thrust washer that goes between the rear planetary and driving shell.

Stick on another thrust washer and then the front planetary and annulus gears. Don't forget the thrust washer that goes between them. The planetary should engage the splines in the output shaft.

There should now be just barely enough room to put the snap ring on the end. If there's too much extra space, you probably forgot a thrust washer. If there's not enough space, you probably put an extra thrust washer in between the rear planetary and annulus gears... Not that I would have wasted 2 hours before I figured that out.

Use a thin screwdriver to line up the teeth in the clutch disks and install the rear clutch pack. Make sure all the clutch disks have engaged the front annulus, and it has slipped all the way on. Don't forget the little washer that goes between the end of the output shaft before the clutch pack.

For the front clutch pack, line up the clutch teeth and fully seat the front drum into the rear clutch retainer. The lugs on the front drum should engage the slots in the driving shell. Don't forget the fiber washer that goes between the rear clutch retainer and the front drum.

Next, wiggle the front band into place, and attach the linkage hardware. The pivot for the front band lever gets installed through a hole inside the bellhousing. After the pivot is in place, the hole gets closed up by a pipe plug.

Finally, install the front pump. Use some long bolts or threaded rod as guides so it lines up properly. Don't forget the sheet metal vent baffle.


Step 13: Parking Mechanism

Here is a picture of all the pieces for the parking mechanism. The needle bearings go into the pivot of the lever in the upper left corner. First, install the finger that engages the parking gear. There is also a spring that goes in there underneath the finger.

Next comes the apply lever. The pivot goes in via a small hole at the bottom of this picture. The rubber seal around one end of the pivot should be oriented down in this picture.

Next is the parking cable grabber thingy. The end of the spring has a bend that goes through the small hole in the apply lever.

Finally, put the cover on


Step 14: Install the Tailshaft Housing

Not too much here. It just slips on. Bolt the housing to the main case. Install the output yoke on the end of the output shaft. Here is a picture of the whole transmission except for the valve body.

While you're here, you can install the neutral safety switch.


Step 15: Disassemble Valve Body

Before you start here, clean the work area again. Lay out two large, clean towels. One will be where you disassemble the dirty valve body and lay the pieces out in order. The other towel will be to place the pieces back in order after they have been cleaned.

The valve body is the brains of the transmission. There are many springs, ball bearings and precision machined valves in here. As you are taking things apart, be careful not to lose any small pieces, or scratch any of the surfaces.

Here's what it looks like to begin with. There's those packing bits again... Also, notice all the crud and varnish caked on. Now, turn it over and remove the 3 slotted screws, and the 14 screws that hold the valve body to the transfer plate. Leave in the two that hold down the reverse blocker valve at the top of the picture.

Leave the valve body upside down and take the transfer plate off. Remove the 6 screws that hold the steel plate to the transfer plate, and you'll be left with this. Take out the check valve and the reverse blocker valve.

Set the transfer plate aside and go back to the valve body. Remove the six check balls. Notice that one of them is larger than the others.

Remove the three screws that hold the bracket for the line pressure and torque convertor valve springs. Remove the line pressure valve and the torque convertor control valve.

Remove the little clip from the throttle input shaft and take off the rooster comb. Pull out the throttle input cam, manual valve and throttle valve.

Remove the cover plate to expose the governor and shuttle valves. To remove the shuttle valve, remove the E clip that holds it in, located off the top of this picture.

Remove the cover to get at the shift valves and springs.

Finally, remove the cover and regulator valves.

Here are a few pictures of all the valves and how they fit together.

Clean everything thoroughly. Here's a picture of all the same valve body parts after being cleaned. Use whatever you can to get into all those crevases and get every bit of crud out. Anything left in there can get stuck in a valve or check ball and make the transmission malfunction.


Step 16: Assemble Valve Body

Put the check valve back in the transfer plate and put the steel plate back on the transfer plate. All the valves and plugs should go back in the same way they came out. Put the check balls back in place. For my kit, it said to leave one of them out, and to drill out a passage. If you're rebuilding back to stock specs, you'll want to put them all back in. Remember to put the larger ball back in the right place.

Put the transfer plate on top of the valve body and install all the screws.
Turn it back over and install the spring retainer bracket, throttle lever shaft and rooster comb.

The final product


Step 17: Install the Valve Body

This part is pretty simple, too. Just line up the holes and install the screws. Here is two pictures of the installed valve body, and one more with the filter in place. The filter is the other part you'll need to get seperately, since the one that comes in the kit is for a '66 and later transmission.


Step 18: Install the Pan

Only one more thing to do. Install the pan.

Voila! you are done!