Like many of you, I have(well, had) a 47RE trans that was in need of an overhaul.. While I could have easily sent a check worth half the value of my truck to Suncoast or Georend, I decided to try to tackle the overhaul myself. Since I have never seen a thread on this, I also decided to capture the process as well. In total, I have apparantly taken 167 photos!
About myself, I have never rebuilt an automatic before this one. I have been through various FWD manual transaxles, and did a few shift kits(with low levels of success). I have never torn down an automatic completely, but last year I built my confidence when I rebuilt the overdrive unit.
First, this is not intended to replace the need for the factory shop manual! The purpose of this is so you can see the steps, and determine if you feel comfortable performing this job, and to let you see what some of the parts look like and any special tips I may have to offer.
Second, the scope of this thread will be overhauling the main portion of the transmission. If you need a how to for removing the trans from the truck, this is probably above the level you want to be at. For valve body disassembly and assembly, there are other threads. For the overdrive portion, I did a complete write up on rebuilding the overdrive unit in the truck without removing the transmission from the truck last year. You can follow that thread for the OD unit
First here is a cutaway of the 47/48RE transmission.
Lets get started.
Jack up the truck, and remove the transmission.
Slide the converter off the transmission and drain it.
Flip the transmission on the front end, and remove the valve body.
Remove the accumulator piston and spring.
Remove the overdrive unit by removing the 7 bolts. See my other thread on removal of the OD unit and overhaul at https://www.cumminsforum.com/forum/98...n-rebuild.html
Remove the OD piston spacer, and the thrust bearing. Note the lip on the ID of the thrust bearing and its orientation.
Find a suitable stand for the transmission to set it on the outlet end. A nice mud tire rim would be perfect, all I had was an old VW wheel I had to space off the floor using 2x4s.
Remove the bolts for the pump. Remove the pump. I didnt realize I forgot to take pictures of this, but the best way would be to use two slide hammers to pull it out. The bolt holes in the pump are threaded. I dont know the threads, but they are the same as the OD unit. If you don't have a slide hammer, you can make one out of some long all thread, a pair of sockets and a pair of nuts. What I did, which I dont recommend, but I did, was to lift the trans out of my make shift stand and lower it onto the floor quickly and let the shafts pop the pump loose from the body, and then I used a pair of OD unit bolts to lift it out of the casing.
Once the pump is out, remove the intermediate band. First, loosen the adjustment jam nut and back the screw out. As you can see, mine had no adjustment left!
Squeeze the band together, and remove the band strut and wedge anchor.
Lift the band from the casing.
Lift the front and rear drums out of the casing by the input shaft.
Lift the front drum off of the rear drum. Notice that brown spacer ring on the rear drum face. Do not lose it!
Lift the intermediate shaft and planetary gear assembly out of the transmission case. Place it temporarily in a stable place, such as a rear rack on a quad, LOL..
Two things to not lose track of, or forget the orientation. On the input end of the intermediate shaft, first you will see a thrust washer.. followed by a spacer. DO NOT LOSE THESE.
Lay the components out in a safe place.
Remove the reverse drum, and sprag, and OD piston retainer. I did not take photos of these at tear down, so here are the installation photos in reverse.
First, remove the snap ring from the middle of the drum.
Then remove the thrust washer
With the thrust washer and snap ring removed, remove the drum.
Once the drum is removed, remove the rear band. The pins for the rear band and band lever slide out of the back of the casing.
Remove the sprag. Notice that one side of it has ribs on the outer diameter that fit into the race in the casing.
With the sprag removed, you can see the race for the sprag. Do not try to remove this, it is pressed in the casing.
Flip the casing over, and remove the OD piston retainer by removing the screws from the casing.
Carefully pry the OD piston retainer from the casing. I used a pair of screwdrivers to gently lift it from the casing. Installation is alot easier.