Part 5 Rebuilding the Transmission Main Case: Rebuilding and Installing the Main Planetary Assemblies

Now I'm ready, and aching (!) to get to the gear train of the main case. Start with the two planetary assemblies at the rear of the transmission.

First, get the driving shell and sun gear (you can see the sun gear at the left rear). I did install some new bushings into each side of the sun gear, but I don't have photos of that process. It was fairly painless. They went in easily with my press and a socket.



Lube the sun gear up in some fresh ATF. This whole process with the gear train is messy!



Now find the thrust washer with 4 tangs. These interface with the sun gear teeth.



Place it on the driving shell, aligning the tangs with teeth in the shell.



Now take the sun gear and slide it into the teeth in the driving shell. Now this is important: I found that the longer section of the sun gear (it's not quite divided in half) needed to be up, or to the REAR of the transmission.



The sun gear in place.



Flip the driving shell over and install the associated snap ring onto the sun gear inside the driving shell. It's a wire type.



Now set this assembly aside until needed later.



Now we'll work with the intermediate shaft and the rear annulus gear. The rear annulus gear is the one with internal splines that mesh with the intermediate shaft.



Slide the annulus gear onto the forward end of the intermediate shaft with the teeth of the annulus gear toward the front of the transmission.



Find the thrust washer with notches that match the splines on the intermediate shaft. Apply some assembly lube to both sides.



Slide it onto the intermediate shaft and into the rear annulus gear, meshing it with the splines on the intermediate shaft.



Now soak the rear planetary gear assembly in some fresh ATF. The rear assembly is the one with the driving tangs on the outer circumference.



Slide the rear planetary onto the intermediate shaft, meshing the planetary gears with the gears in the rear annulus.



Make sure the rear planetary gear assembly is fully bottomed into the rear annulus gear.



Now find a new tabbed thrust washer with 4 tabs. The old one on the right shows significant wear.



Spread some assembly lube on both sides of the tabbed thrust washer.



Now install the thrust washer on the forward side of the rear planetary gear, interfacing the four tabs with the four associated slots in the planetary gear. Now is a good time to put some assembly lube on the intermediate shaft surfaces that the sun gear will ride on.



Now take the driving shell assembly and install it on the front end of the intermediate shaft. The sun gear should slide down into the rear planetary gear assembly.



Find the new tabbed thrust washer with 3 tabs. The old thrust washer is on the left. It shows a bit-o-wear!



Apply assembly lube to both sides of the thrust waster.



Install the thrust washer with the tabs interfacing with the three holes on the inside of the driving shell.



Now we need the front annulus gear and front planetary gear assembly.



Soak the front planetary gear assembly in some fresh ATF.



Find another new 4 tabbed thrust washer. Again, the old one on the left shows some good (bad?) wear.



Coat both sides of the thrust washer with assembly lube and install it onto the back end of the front planetary gear. The back side has a lip the extends up at the inside circumference.



Place the front annulus gear over the front planetary gear assembly. Make sure the planetary gears fully engage with the annulus gears.



Now slide this assembly, annulus gear first, onto the front of the intermediate shaft and into the driving shell.



Here's the front planetary/annulus assembly in the driving shell.



Install the associated snap ring on the end of the intermediate shaft.



The snap ring installed.



Now find a small wood block and set the forward end of the intermediate shaft on it.



Jiggle the shaft up and down and bit, rotate the components, maybe tap it soundly against the wood block. This is to seat the components so that we can take a measurement.



This gap at the top (rear) of the rear annulus gear is what we want to measure.



Use a feeler gauge to find the gap. The FSM says we want a gap between .006" and .048". My measurement came in right around .010". This is good since it gives me lots of room for wear (heaven forbid!) of the thrust washers. If this measurement is out of spec you adjust it by using a thicker or thinner snap ring on the forward end of the intermediate shaft.



Now coat the surfaces of the intermediate shaft that will ride inside the overdrive piston retainer.



Apply some assembly lube to the internal surfaces of the overdrive piston retainer.



Now slide the completed planetary gear train into the front of the transmission. Slide the rear of the intermediate shaft into the overdrive piston retainer.



Notice the tangs of the rear planetary gear assembly interface with notches in the rear drum.



Make sure the planetary assembly is fully seated against the rear drum.



One last thing! Apply some assembly lube to the end of the intermediate shaft. Find the small thrust washer.



Install it on the end of the intermediate shaft.



Here's the planetary gear train looking in from the front of the transmission.



Whew! Long post. Next: rebuilding the rear clutch.

Part 4 Rebuilding the Transmission Main Case: Installing the Front/Intermediate Servo Piston and Lever

Now I'm ready to install the front piston and lever. The band gets installed with the front clutches.

I decided to upgrade this piston to a "no leak" item. The new piston has double seals as well as a rubber seal and bushing on the rod guide. It's all billet material as well. The old one just had a bushing. On the left is the original part. On the right is the upgraded piston. You can see the double seal rings as well as the rubber seal the rod guide for the piston rod. The spring and snap ring are reused. I upgraded the spring earlier when I installed the Transgo shift kit.



The smaller seal is a lapped teflon type. So spread a little assembly lube on the seal area and groove in order to hold it in place. Spread some fresh ATF on the larger metal ring seals. Offset the ring gaps by 180 degrees.



Then lube the bore of the servo with some fresh ATF.



Slide the piston down into the bore. It turned out to not be too hard. I had to coax the two metal rings a little. But, overall, much less effort than the rear piston was.



Place the piston spring onto the piston.



Lube the rod guide seal and bushing with a bit of assembly lube.



Then slide that onto the piston rod, seal facing down.



Make sure the metal sealing ring clears the groove for the snap ring.



Use some sort of c-clamp to compress the assembly a bit. The FSM suggests a valve spring compressor with a special end. I found this clamp to work fine.




Install the associated snap ring.



All tidy!



Now let's install the band lever. I upgraded this part as well. The OEM lever is a 3.8:1 ratio. I opted for a 4.2:1 ratio. Just a bit more holding strength. There is a 5:1 Mopar lever specced for high horsepower Hemi motors. I decided that may be overkill...although it was cheaper than the 4.2 lever.



Spread some assembly lube on the pivot rod.



Install it into its bore through the pump side (externally in the bell housing) just far enough so you can get the lever on.



Here's the orientation of the lever and it's slot in the case. The long end of the lever contacts the piston rod on the servo just installed. (Naturally I have no photo of the lever insalled! You'll see it later.) You can see the pivot rod to the left of the lever in the case.



Spread a little sealant on the pipe cap plug that holds the rod in place. You don't want this leaking after you've got the transmission buttoned up and into place. I used a little hi-temp RTV.



Torque that to 13 foot*pounds.



Here it is all in place and sealed.



Next: rebuilding the rear planetary assemblies. This could be a long one! I may break it up into a couple of posts.