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Finally: How to rebuild your 47/48re

74K views 56 replies 32 participants last post by  rockin345 
#1 ·
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.

NOTES:
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 http://www.cumminsforum.com/forum/9...4-47re-overdrive-remove-teardown-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.

 
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#2 ·
At this point you almost have a bare casing.

Lets rebuild the clutches.
Note, I thought I had a 47RE. Apparantly the previous owner installed a 48RE which is slightly different. My front drum has 5 clutches, while the 47RE comes stock with 4 clutches. My rear drum has 4 clutches like a 47RE, however mine have 93 teeth, as opposed to 62 teeth. If you get to this point and find the same thing, if your rebuild kit is for a 47RE your thrust washers and clutches will be wrong!

FRONT DRUM:


Remove the snap ring from the drum.


Remove the selective steel


Remove the first clutch plate.


Remove the first steel plate.


Continue this until all clutch plates and steels are removed.


Note that the next disassembly steps require removing that snap ring that is under considerable spring pressure.


I quickly fabricated an ugly strongback to use on the press to compress the spring. You want to push down on the steel washer plate, but give room for the snap ring to expand. I used some 1x1 box tubing.




With the spring compressed, remove the snap ring.


Releive the pressure off the press and take the assembly back to the bench. Remove the snap ring.


Remove the plate


All of those springs are just setting there on the pins on the piston. Note the grouping, and remove the springs.


Once the springs are removed, remove the piston.


Here is the empty front drum.


Remove the seal from the front drum.


Remove the seal from the front piston.


CLEAN ALL THE PARTS.
 
#3 ·
Marinade your clutches in ATF.


GET SOME TRANS ASSEMBLY LUBE:


Install the lip seal on the ID of the drum. Note, that this is a lip seal, meaning that it has a lip. The lip needs to point to the bottom of the drum, since the pressure comes from the bottom of the drum, and is intended to seat the lip.



Same thing for the piston. This is also a lip seal, and the lip needs to point towards the back of the drum. If you install it backwards, the pressure will just blow the lip inwards and the fluid will seep past the seal.



Lube the hell out of the areas that the seals will have to seat against.


Carefully install the piston into the drum. Work it on by slightly angling it, and pushing it softly. The manual says you can use spatula tools to help with this, but I think they are full of crap. DO NOT TEAR THE SEAL.. Be slow and careful so you don't fold over the lip.


Once the piston is installed, install the springs.


Then set the retainer plate.


Compress the springs, and install the snap ring.


Install your first steel plate.


Install your first marinaded clutch.


Repeat for remaining steels and clutches.


Set the input shaft into the center of the clutches to line up all the teeth and center the clutch discs. Rotate the input shaft inside of the clutch pack as it drops one at a time into the clutch discs. Once you lined up all the discs, remove the input shaft.


The clutches should be lined up as shown.


Install the selective steel.


Install the snap ring.


Measure the clearance between the high point in the waves of the snap ring and the selective steel. I forget the range, but I think it was .070-.120. If you have too much or too little clearance, you have the wrong thickness clutches or steels or may need a different selective steel.


At this point the front clutch drum is assembled.
 
#4 ·
Rear clutch drum.

Set the rear drum up on the input shaft. I was a little slow to realize something to support this would be handy. Later you will see I supported this kind of thing on a large wire spool. Remove the snap ring.


Remove the selective steel.


Remove the clutches and steels like was done in the front drum.
Remove the pressure plate.


Remove the wave snap ring.



The drum will probably fall down like mine.


Remove the cushion ring.


Remove this plate, I cant remember what its called.


Remove the piston.


Flip the shaft over and remove the three shaft seals on the input shaft.


CLEAN EVERYTHING
 
#5 ·
Replace and lubricate the shaft seals.


Replace and lubricate the seal on the OD of the piston. Remember, this is a lip seal, and you want the lip to face the smooth side of the piston in this case.


Replace the ID piston lip seal. It fits in the groove inside the piston.


Lubricate all mating surfaces, and carefully install the piston just as was done in the front drum.


Set the drum in place to be installed. Notice in the next pics I got smart and supported the components. I used a cable reel and the rear band.



With the drum and shaft supported, insert that plate.


Then install the cushion ring.


Install the wave snap ring.


Install the pressure plate.



Install a friction, then a steel, over and over until all frictions and steels are installed.





Install the selective steel.


Use the front planetary to line up the teeth in the clutch pack. You can skip ahead to that section to see how to tear down that section, or you can use the entire intermediate shaft assembly too.


The clutches should be lined up and centered as shown.


Install the wavy snap ring.


Check the clutch pack clearance. It should be .025 to .040" if I recall correctly. Consult the manual. If it is too tight or too lose, you may have the wrong thickness clutches, steels, or selective steel.



The front drum is now built and ready for installation.
 
#6 ·
Intermediate shaft and planetaries:
Since I have a 48RE, I have 6 pinion planets. If I had a 47RE I would have had 4 or 5 pinion planets. Note that the thrust washers fit in little holes in the planets, and since I have a 47RE rebuild kit, none of the thrust washers would fit. I mic'd my thrust washers and found little to no wear, so I reused mine.

Remove the snap ring from the input side of the intermediate shaft.


Remove the front planetary set.


Remove the thrust washer between the front planetary and the shell.


Flip the assembly over, onto the shell. Lift the intermediate shaft out of the shell/sun gear.


Lift the ring gear from the rear planetary.


Remove the thrust washer from the rear planetary.


Remove the rear planetary from the sun gear/shell


Remove the thrust washer from the shell. Note that there is a spacer under the thrust washer, retained by a circlip. I did not remove these components, as my sun gear was in good condition.


Disassemble front planetary. Notice the plastic spacer.


CLEAN ALL COMPONENTS.



Lubricate the thrust washer and place it on the front end of the rear planetary set.


Place the rear planetary over the sun gear as shown.


Lubricate and install the other thrust washer on the rear planetary.


Install the rear planetary ring gear.



Lubricate the bushings inside of the sungear and insert the intermediate shaft.


Lubricate and install the thrust washer between the shell and front planetary.


Lubricate and install the thrust washer on the back side of the front planetary.


Lubricate and install the plastic spacer ring over the front planetary snout.


Install the ring gear over the front planetary.


Install the front planetary over the intermediate shaft.


Install the snap ring to retain the front planetary.


Intermediate shaft assembly is complete.
 
#7 ·
Servo's and other case stuff.

Clean the casing.

OVERDRIVE PISTON RETAINER.

Check the OD Piston retainer for signs of wearing and scoring, since the reverse drum rides on this.


Place a new gasket on the backside of the retainer, making sure it is orientated properly as to not block off flow to the OD piston.


Lube the retainer, and carefully install into the casing.


Torque the bolts to factory manual specification.


FRONT SERVO, AND BAND APPLY LEVER.
Using a 1/4" ratchet and extension, remove the plug from inside the bellhousing area for the front band lever.


Slide the front band lever pin out. You may have to tap the case on the bench to get it to slide out.


Remove the front band lever.


Remove the front servo cover. THIS IS UNDER SPRING PRESSURE. Use a C-clamp, and somethign that will sit flat on the cover to compress the spring. I used the discs for a taper roller bearing race driver. Compress the spring and remove the snap ring.



Release the pressure from the spring.


Remove the front servo cover.


Remove the spring for the front servo.


Remove the front servo piston and pin.


Here are all the front servo parts removed.
 
#8 ·
This is the installation of the upgraded Sonnex billet front servo. It comes in the front band kit from PATC.


Install the pin in the piston, and install the snap ring.


Install the teflon sea and d-ring rubber seal on the small diameter side of the piston. Lubricate liberally.


Install the sleeve over the piston, it should slide easily back and forth. Then install the seals onto the sleeve.


Install the large D ring seal and split seal on the piston.


Install the outer seals, and the inner O ring seal on the cover.


Remove the sleeve from the piston, and install it in the casing. Be sure to lubricate the casing!


Check that there are no burrs on the casing for the bore for the piston! Especially where you pried the snap ring loose(lesson learned). It should be nice and smooth.. Lubricate everything liberally, and install the piston.


Install the servo spring.


Lubracte the seals and casing for the cover.


Install the cover, compressing the spring with a C-clamp again, and install the snap ring.


Prepare to install the band apply lever. This is a 5:1 ratio apply lever which holds the band tighter. Stock was 3.8:1.


Slide the pin partly in.


Set the lever, and insert the pin fully. Reinstall the plug in the bellhousing area.


REAR SERVO:

Getting a C-clamp around the casing is nearly impossible. I compressed the spring by hand as shown then managed to get the snap ring off.


Once the snap ring is removed, remove the spring plate.


Remove the large spring:


Remove the piston


Clean all the crud out of the bore.


At this point, my battery went dead :(
Remove the pin from the piston by compressing the spring in a bench vice to get the pressure off the spring.
Assemly wise, is opposite of reverse except that I installed a billet rear servo kit from PATC.
 
#9 ·
REAR SPRAG:
Clean the race for the rear sprag spotless.


Lesson learned the hard way.. Do not lubricate the sprag prior to installation. Install it dry.


It should set down slightly in the hole as shown.


Install the upper rear band pin.



Lay the rear band in the casing. The two tangs on the band will go against the pin.


Lubracte the thrust faces on the reverse drum, but NOT the diameter of it that rides on the sprag rollers! The purpose of the sprag is to be a one way clutch. If you slop it up with lube, it won't work!


Lube up the snout on the OD retainer, and set the reverse drum into the sprag.


Test it, it should spin freely in one direction, but lock up if you try to turn it the other direction. If you can spin it both directions, something is wrong.
Lubricate the face for the thrust washer.


Install the thrust washer.


Install the snap ring.


Install the rear band apply lever and pin. The pin slides through the back of the casing, and the O rings go on the outer edge. The pointed end goes in first.

 
#10 ·
FINAL ASSEMBLY
Lubricate the journals of the intermediate shaft liberally with lube, and the ID of the OD Piston retainer.


Due to the fact I only have two hands, I could not photo dropping the intermediate shaft assembly into the casing. Set the intermediate shaft into the casing, and ensure the tangs in the rear planetary engage the notches in the reverse drum. Lubricate and install the spacer that hopefully you did not lose.


Lubracate the thrust washer and install in the input shaft. Note, it has 3 tabs, one of them is offset so it can only go in one way.


Set the input shaft into the shell/front planetary.


It should look like this when installed.


Install the front drum over the rear drum. I cant beleive I forgot to take a picture of that. Ensure the tangs on the front drum engage the tangs of the shell.

Set the front band into the casing. Note, this is an upgraded band from PATC. It is a rigid band, which means the body is cast steel instead of sheet metal. It has a heavy carbon fiber lining, is wider than stock, and greatly improves the holding power for 2nd gear. Highly recommended if you tow alot.


Back out the band adjusting screw, and install the wedge anchor between the screw and the band. This is a billet anchor from PATC.


Push the two ends of the band together with your fingers, and install the band strut. This is a billet strut from PATC.


Clean the pump, and replace the seals on the snout as well as the input shaft seal where the converter rides. Lubricate all seals, as well as the spacer.


Using tranny lube, install a new paper gasket and O ring around the pump body.


Install the pump, torque the bolts to the factory manual specs.


Adjust rear band. I'd list the spec, but its in the manual, and I forget it.


Adjust the front band.




At this point, you are ready to do the general installation stuff of the valve body, OD unit, etc...

To make things easier to handle, at this point I installed the pan, and got the trans under the truck and on the tranny jack. I then installed the converter(and an SFI flex plate) and installed that part of the transmission.

Once that was bolted up in the truck, I installed the OD unit, then the accumulator, and the valve body..

Then the transfer case and the rest of the mundane tranny install stuff.
 
#14 ·
Welcome! Hope it helps!

Sent from my Motorola Atrix using Tapatalk
 
#15 ·
Thanks great right up. The more I read the more I want to try a rebuild on my own and save$$$$$$$$$$$$
 
#17 ·
Seems like so does everyone, and mostly its the same stuff. I got the aftermarket parts from Patc. I would have bought everything from them but I wanted to be sure of what I had. Unless you are the original owner and know what's in there or its never been apart, you have no clue. That said, once I found out what frictions I needed I got them from Daaco. They are high energy raybestos and all of them including ones for the overdrive unit was like 85 dollars.

Sent from my Motorola Atrix using Tapatalk
 
#19 ·
After looking at the thread link that Chugginsmoke05 posted detailing BoostedOne's rebuild, I think I can handle it with the ASTG manual as well. I plan to do a TC, VB or shift kit, Flexplate, and billet input when I tear into it. Just trying to decide whether to go with DTT or Goerend parts.

Thanks again to everyone that replied. I will update when completed.
 
#20 ·
Marinade your clutches in ATF.


GET SOME TRANS ASSEMBLY LUBE:


Install the lip seal on the ID of the drum. Note, that this is a lip seal, meaning that it has a lip. The lip needs to point to the bottom of the drum, since the pressure comes from the bottom of the drum, and is intended to seat the lip.



Same thing for the piston. This is also a lip seal, and the lip needs to point towards the back of the drum. If you install it backwards, the pressure will just blow the lip inwards and the fluid will seep past the seal.



Lube the hell out of the areas that the seals will have to seat against.


Carefully install the piston into the drum. Work it on by slightly angling it, and pushing it softly. The manual says you can use spatula tools to help with this, but I think they are full of crap. DO NOT TEAR THE SEAL.. Be slow and careful so you don't fold over the lip.


Once the piston is installed, install the springs.


Then set the retainer plate.


Compress the springs, and install the snap ring.


Install your first steel plate.


Install your first marinaded clutch.


Repeat for remaining steels and clutches.


Set the input shaft into the center of the clutches to line up all the teeth and center the clutch discs. Rotate the input shaft inside of the clutch pack as it drops one at a time into the clutch discs. Once you lined up all the discs, remove the input shaft.


The clutches should be lined up as shown.


Install the selective steel.


Install the snap ring.


Measure the clearance between the high point in the waves of the snap ring and the selective steel. I forget the range, but I think it was .070-.120. If you have too much or too little clearance, you have the wrong thickness clutches or steels or may need a different selective steel.


At this point the front clutch drum is assembled.
too tight here and it will slam into reverse
 
#21 ·
Rear clutch drum.

Set the rear drum up on the input shaft. I was a little slow to realize something to support this would be handy. Later you will see I supported this kind of thing on a large wire spool. Remove the snap ring.


Remove the selective steel.


Remove the clutches and steels like was done in the front drum.
Remove the pressure plate.


Remove the wave snap ring.



The drum will probably fall down like mine.


Remove the cushion ring.


Remove this plate, I cant remember what its called.


Remove the piston.


Flip the shaft over and remove the three shaft seals on the input shaft.


CLEAN EVERYTHING
the top snap ring is the selective adjustment for clearance on this pack
 
#22 ·
Intermediate shaft and planetaries:
Since I have a 48RE, I have 6 pinion planets. If I had a 47RE I would have had 4 or 5 pinion planets. Note that the thrust washers fit in little holes in the planets, and since I have a 47RE rebuild kit, none of the thrust washers would fit. I mic'd my thrust washers and found little to no wear, so I reused mine.

Remove the snap ring from the input side of the intermediate shaft.


Remove the front planetary set.


Remove the thrust washer between the front planetary and the shell.


Flip the assembly over, onto the shell. Lift the intermediate shaft out of the shell/sun gear.


Lift the ring gear from the rear planetary.


Remove the thrust washer from the rear planetary.


Remove the rear planetary from the sun gear/shell


Remove the thrust washer from the shell. Note that there is a spacer under the thrust washer, retained by a circlip. I did not remove these components, as my sun gear was in good condition.


Disassemble front planetary. Notice the plastic spacer.


CLEAN ALL COMPONENTS.



Lubricate the thrust washer and place it on the front end of the rear planetary set.


Place the rear planetary over the sun gear as shown.


Lubricate and install the other thrust washer on the rear planetary.


Install the rear planetary ring gear.



Lubricate the bushings inside of the sungear and insert the intermediate shaft.


Lubricate and install the thrust washer between the shell and front planetary.


Lubricate and install the thrust washer on the back side of the front planetary.


Lubricate and install the plastic spacer ring over the front planetary snout.


Install the ring gear over the front planetary.


Install the front planetary over the intermediate shaft.


Install the snap ring to retain the front planetary.


Intermediate shaft assembly is complete.
this was 48RE gear train and your rear clutch had 48RE fibers in it
 
#23 ·
Boosted one and Baxy
Thank you both for the EXCELLENT info
 
#25 ·
You're welcome everyone.. Did it hoping it would do just that, boost someones confidence.
I have about 800 in the rebuild, including the tranny fluid and break cleaner which was 120 bucks itself. Note that from previous work, it already had a shift kit in the valve body, a GM gov press solenoid upgrade, and I reused my converter which is a single disk billet. I would have liked to do a new converter, but it just wasnt in the funding.

Baxy is right on the 48RE internals. I actually think its a 48RE trans with a 47RE valve body in it.. My OD unit was also full of single sided, 48RE OD Direct frictions.

And yeah, stock shafts.
 
#26 ·
I'm looking at building my trans sometime this summer hopefully,( depending on funds available lol), but this is by far one of, if not the best write ups I've seen on this forum.

My dad owned a transmission shop for 20 years ( sold in 2009) and is now a diesel mechanic for a drilling company, so I grew up in a mechanics world. Fortuantely for me, this will help me out a TON on savin some cash too. I've never done a rebuild totally on my own, but helped him tear down and rebuild several transmissions over the years. For someone who's never been through an AT before, you did a heck of a job man! Takes a lot of guts and mechanical ability to just jump in to a job like this. Nice work,and thanks again the awesome write up! :thumbsup:
 
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