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How to: 5R55E Rebuild DIY Diary

Replacement O/D Planetary

My replacement (used) O/D planetary arrived. It is not exactly the same as the original, but I believe it will work. New on left, old on right.

The reluctor ring is what I would describe as upgraded - more resistant to deforming - and there is an additional plastic ring in the first pic. There is also a retainer in the center for the input shaft. Any reason this part won't work?

I also decided to remove the transfer case for ease of installation, and while I was at it removed the shift linkage in order to replace that seal, and the tail housing to replace that gasket. There was a lot of caked on grease on the case, and while I was cleaning it, I decided replacing the external seals/gaskets was a good idea. Still waiting for a few parts, then I will begin reassembly.

The OD sprag was tricky to re-insert by hand, but I got it in. I have re-assembled the OD drum with new seals, steels, and frictions. The clearance was within spec, so the existing ring was fine. So far so good.

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Your new planet is from a 5R55W/S transmission, I have never swapped them into a 5R55E before. It may work, you need to check to make sure the little sun gear that spun the bushing out fits into the planet gears and the "star" washer that fits onto the little sun gear clears the plastic dam that the new planet has. Also need to make sure the planet fits the ring gear that is on the center shaft, if the sun gear does not fit the ring gear wont either.

The ring around the new planet is there for a speed sensor that the 5R55W/S has on the outside of the case, the sensor reads the openings on the ring as they pass by the sensor like the sensor on your center support reads the other openings that both planets have.

Re-assembly update

I've partially checked fitment of the replacement OD planetary, more to come on that. In the meantime, I began re-assembly.

Here we have the case "tail-up" with the extension housing resting on top:

I spent a fair bit of time de-greasing the trans and t-case, those things were nasty!

This is backwards assembly, but here is the parking pawl disengaged with the extension housing on, but without the parking gear in place (you have to put the parking gear in before the extension housing in reality):

And here is the parking pawl engaged:

Same shots but now with the parking gear in place (and a washer behind it):


I had always been curious about how the linkage did it's job. Now you know!

Here we have assembled the output shaft, reverse sprag, 10B thrust bearing, and reverse ring gear:
And a closeup with the snap ring on the output shaft in place:

Here we have the reverse planetary (with the #'s 8 and 9 thrust bearings installed, and 10A output shaft sleeve - basically a plastic cone), and the reverse band installed (with the reverse servo - the shiny bit at the top of the pic is the tip of the servo - temporarily held in place to hold the reverse band in place during re-assembly):

That's it for today...

Re-Assembly Complete

The forward clutch required quite a bit more air pressure to move the clutch pack than the manual suggests. The manual states that no more than 20 psi should be applied when air testing any of the clutch packs, however this one required something in the neighborhood of of 60 psi to move.
I believe part of the reason for this is pressure leakage between the drum and the center support (though it was impossible for me to verify). Here is the setup for air testing this drum:


Initially, I did not apply higher pressure. Thinking something was obstructing air flow, or possibly a bad seal, I disassembled the drum completely, then checked for air flow at the air inlet of the drum here:

I thoroughly cleaned and blew air through the ports in both directions. There was air flow through the port, though it seemed a bit weaker than it should have. I could not detect any damage to the center support or interior of the drum that would cause pressure loss. Does this indicate a problem? Hopefully this is normal with this drum. At any rate, I reassembled the drum and found that the clutch would move with higher pressure applied. I'm not sure why the manual recommends such low pressure when the trans experiences much higher pressure in operation. My guess is safety concerns.

Everything else went smoothly.

Here we have the drum assembled, checking the clearance with feeler gauges (.055 - .083 inches), I had to stack two to get the thickness required:

Next is the forward geartrain assembly, here are the pieces:

First we place the forward clutch into the intermediate drum (which air tested fine with low pressure) with the bearing b/w:

Next we insert the forward ring gear with the washer b/w:

Followed by the bearing then the forward planetary:

Followed by the forward sun gear/input shell:

That assembly is together. Next we turn to the overdrive assembly. Here are the parts:

First we insert the OD planetary into the center shaft/sprag with the bearing b/w:

This planetary is a replacement part from a W/N/S (not E) model, but the fitment seemed just fine in all aspects. Here we check that the sprag is doing its job allowing counterclockwise rotation but not the other way. Next we insert the front sun gear into the OD planetary:

Sidebar: the manual refers to the OD drum (and related parts) as the "front" drum - these terms are interchangeable in my mind. But front is too similar to forward, which is actually the drum in the rear of the case. The nomenclature could be better, but labeling and pictures help immensely in keeping it all straight.

I seem to have missed a photo of the "star" coast clutch adapter, but it pops right on the sun gear. No clearance issues with the plastic damn in the revised OD planetary.

Next we insert the forward geartrain assembly into the case along with the intermediate band and apply/anchor struts:

Followed by the #4 bearing then the center support (here you can use the input shaft to align the geartrain and the center support):

Next we insert the retaining bolt/cage through the bottom of the case as well as insert the TSS sensor and route the wire to the connector:

Next we insert the #3 bearing then the OD assembly into the case (there's the star adapter):

Followed by the OD/coast clutch drum then the OD band and apply/anchor struts:

I did not disassemble the pump, so next goes the input shaft, then bellhousing/pump assembly including the #1 washer:

Bolts torqued to 35 ft lbs.

Here's a money shot of the case as it stands proud on the stand :D:

Next we insert the servos, covers and snap rings (don't mix them up). The tool was not necessarry, just apply some pressure with your palm and they stick right in:

Next we torque the intermediate band to 10 ft lbs then back off 2 turns, followed by the OD band to 10 ft lbs then back off 2 1/2 turns. I had to be a little approximate here as the end of the adjuster bolts are square, which doesn't play well sockets, my only means of employing a torque wrench. So I used an 8mm wrench then stuck a torx bit in the other end of the wrench which connected to to torque wrench - this of course lengthens the lever and increases torque a bit, hence the approximation.

Tighten the locknuts do 40 ft lbs while holding the adjuster bolt in position. This had to be approximate as well as holding the adjuster bolt in place blocks the use of a socket - same problem:

If I had followed the order of the manual, my trans range sensor would still be off at this point, but I didn't, so clearance is tight in the intermediate adjuster bolt:

If you loosen the two mounting bolts of the range sensor you can get enough play to thread on the locknut and adjust the bolt, just barely.

It's time for the trans to come off the engine stand:

Stand plate off:

Next we insert the solenoid cable harness (I know my wires are in bad shape, but they are pricey to replace):

Next we install the valve body and gasket (you used a bolt template at removal didn't you? :D):

Note the manual valve is slotted into the shift linkage pin. Torque the valve body bolts to 90 inch lbs in the proper sequence. Next goes the detent spring, reverse servo gasket and cover (careful, the gasket is easy to flip around and misalign), pan gasket, and filter:

Next goes the pan - torque bolts to 125 inch lbs sequencing across the pan:

Almost there! Next we install the OD sensor and the output shaft sensor (top of case), as well as the vent pipe:

On the other side we install the heat shield:

All Done!!! Oh ya you still have to install it... and slap in the torque converter when you're ready

Here's a shot of my empty parts table and all the damn labels (this was a great idea):

And the parts table for those wanting to do something similar:

This was a long job, but it feels good to be done. Also, it gives me the confidence to tackle any other transmission issues i may have in the future on this vehicle or others. Time for a beer or four.

Torque Converter

I decided to take off the flywheel so that I could inspect the rear main seal on the engine:


Really not too bad of a mess back there. Cleaned up:


DON'T DO WHAT I DID!!! Learn from me and put the torque converter in before you drag the trans under the vehicle:


I wasted a bunch of time trying to mate the trans to the block before I realized that i didn't have the TC fully seated. I couldn't for the life of me get it all the way in while horizontal :D so I had to drag the trans back out, then after partially seating horizontally (so you don't dump out all the fluid), stood the trans up vertically (on some blocks so as not to put the weight on the output shaft) then jiggled and rotated until it slid home.

The manual indicated the clearance across the bellhousing to tip of TC shaft should be 0.43"-0.56":


Ya ya I know it's wood and measuring tape, but you get the idea - just shy of a half inch here, looks good.

Then before I dragged it back in there I temporarily put a C-clamp on to hold the TC in place. If the trans is tipped forward, it can unseat and/or fall out - no bueno (this is why I waited to put it in the first place - bad idea):


I've got it pretty much in place now, just struggling to line everything up again and stab it in - a little more patience and cursing should do the trick.


Just checking here, is the OD sensor on the top of the case unused in the E? (the sensor pictured above the DTR in the pic below) This makes sense with the simplified/one-way reluctor ring on the OD planetary, I'm just suprised that I have an actual sensor and not a plug if it goes unused. Otherwise I have no idea where the wire loom for this sensor is....

While I'm at it, here's a shot at getting the most difficult upper mounting bolt with 3 extensions cobbled together, probably 4 ft or so in length, + a u joint:

As you can see the access hatch is open, which is best to use for the other three top bolts. I found it easy to use a mechanics magnet to insert the upper bolts (then slide the magnet off sideways once you're in). The lower 4 can be done from beneath. The long extension approach on this bolt is much easier with the t-case out of the way.

There are 3 types of mounting bolts (out of 8 total), they are arranged by location below (i.e top middle 2 stubby bolts are the top 2 mounting locations, while the long 2 are the bottom locations, and the 4 mid-length are the side locations):

I saw that sensor on your case a few posts back and I thought how ironic that you happen to get a planet that has the correct ring on it to make it work.

So yes the sensor is just plugging the hole and you wont have a connector for it because its not used, but the sensor is working for the first time now but you just dont need it!

More Install Pointers

I thought I would share a few more pointers on the install process.

Here we have the location of the trans fluid cooler line bracket bolt:

It can be accessed through the passenger wheel well next to the oil filter. This frees up some movement in the steel lines to allow for easier removal.

Here we have the location of the fill tube nut/stud:

While it is not a difficult location to see (near top of fill tube), the downward angle required removal of the air intake box, and unbolting the coolant/wiper fluid reservoir (then sliding over to the air box location) in order to gain access.

The top passenger side mounting bolt for the transfer case is most easily wrenched through the access hatch:

This pic is looking backward through the hatch (sorry for bad lighting).

The bottom center mounting bolt for the transfer case must be inserted into the tail housing of the transmission before the crossmember is installed:

There is not enough room to clear the length of the bolt back to the mount otherwise.

JK did you see my note about the higher air pressure needed to actuate the forward clutch (post #44)? Thoughts?

JK did you see my note about the higher air pressure needed to actuate the forward clutch (post #44)? Thoughts?

I dont regulate the air pressure when I build transmissions, I have a air gun that can regulate the air pressure depending on how much you squeeze the handle but I dont know the pressures.

Its not uncommon for pistons in the drums to have bleed orifices or check valves to bleed off air or to regulate the apply, I dont have a loose piston laying around to see if this one has one or not, I believe it does. This can cause the drum to require more pressure to apply.

I would think you will be fine, as we will find out for sure as soon as you are ready to drive it.


I got it all buttoned up last week and it works!!! I am mostly pleased with the results, but I do have some observations after driving a few times:

1) There is a noticeable whistle or whine when idling in all gear selector ranges, this sound stops once the vehicle is in motion. It seems like the noise is coming from the valve body - which was replaced with a reman unit from Central Valve Bodies. I spoke with them on phone, and they were perplexed by the noise. They suggested re-torquing the VB bolts. I might give that a try.
2) Shifting between gears is generally very good - nice and firm. Although I have noticed an occasional clunky downshift (when coming to a stop) from 2nd to 1st. Shifting into gear (i.e. changing the gear selector b/w P/R/D) still seems a bit clunky - although this is not consistent, I have not noticed a pattern as yet (i.e. hot/cold). I am going to guess that the increased pressure required to move the intermediate piston is to blame, but I am speculating.

I am thinking about adding a temp gauge for peace of mind, although I do not plan on any significant towing. Time will tell how good of a job I did.

A huge thanks to JK for guiding me through the process, your help is greatly appreciated. Having been through this once, I can now pass the knowledge on to other members. :salute:

Well... 10,000 miles and a year later aaannndddd the trans failed again :censored:. It is exhibiting identical symptoms as to last time around. I'm scratching my head as to what I may have missed in the last rebuild that would cause such a premature failure. This time I will definitely install a temperature gauge (should have last time). At least I will be able to do the job faster this time, and not have to spend money on tools or the valve body.

I've got the trans out and partially disassembled so far. This time around I decided to pull the transfer case first (I used to think that was a tough job). With that out of the way it is actually possible (and easier really) to remove all of the trans to engine mounting bolts w/o using the interior hatch. You just need to use long extensions. While the front drive shaft really needs to come completely out, the rear driveshaft can be left attached at the rear diff. Got 'er pulled much faster this time. Still managed to make nice mess on the floor during initial disassembly though - maybe next time I'll do better there.

I've already got the pan and valve body off, and the trans mounted on the engine stand. I'll post some picks of disassembly this time, since I skipped that part last time around. At this point I fully expect to find the same damaged parts - input sprag (and consequently marred OD planet and input shaft), and toasted OD drum frictions. Might get away with less than $150 in parts on this one.

Imagine how pissed I would be if I had paid someone a few grand for a rebuild with a one year warranty...

I just reread your post and have to say that is a very nice and thorough write up and great pictures. I read that you didn't remove the pump from the bell. That could very well have caused the same type of damage from not getting the debris out of lube circuit. Also did you flush the cooler lines and cooler before installing repaired trans? The cup plug on the stator with the hole in the picture is how the OD planets get lube. That is a known garbage collection point in these units especially after OD planet failure. Hope you get this issue solved. I applaud you for taking on such a project. Most times our first build wont make it out of the garage let alone 10,000 miles!

gsbarry. Have you located the cause of your transmission failure? As through a job you did the 1st time I am curious to hear what you find.

I have to admit, I did not flush the cooler lines last time around :crazy:, that may well have contaminated the rebuild. I will definitely flush the lines this time. Any suggestions on what to use? Or is any off the shelf trans-solvent-in-a-can good enough? I also plan to add an in-line filter. Anyone know the direction of flow (i.e. which line is hot and which is cold)?

I picked up one of those plastic pump alignment tools for less than $20, hopefully they are good enough (vs the expensive metal ones). This way I can disassemble the pump and check for debris.

I guess another general question I am asking myself, what do you guys use to clean/wipe your parts off? I used shop towels last time around, and I'm wondering if this contaminated the trans with a bunch of lint dust - or if that even matters.

Sure am kicking myself for not remembering to flush the lines. I've been on holiday for a bit - will try to get through the rest of the teardown this week or next.

They sell a chemical for cleaning the lines called cooler cleaner. The lower line has pressure, and the upper line is the return.

Thanks, upper connection at trans is return.

Yes Kooler Kleen to flush cooler and lines. Did you replace Torque Converter? If not you will never get debris out of it unless it is cut and cleaned or replaced. It is a huge garbage collection point. If you don't replace TC I recommend not putting in an inline filter as they will clog and stop flow unless it has some sort of by-pass built in. Good luck!

This is certainly another possible source of contamination, as I did not replace the converter last time around. The ATSG manual shows a few things to check (leaks, stator/impeller interference, endplay) but appears silent as to the need to clean or replace. I recall thinking about this last time around, and my recollection is that since I did not have any hard parts shear or disintegrate (i.e. no significant metal shavings), that the converter was probably fine (although certainly there is friction material).
My reading from other forums is that cutting and cleaning is best left to the pros (which means by a new/reman unit). I have read that some folks drill a drain hole and clean with solvents, but that this is not a terribly effective procedure, and in fact may simply loosen debris, but not remove it, causing further contamination. I guess this job just got a bit more expensive.

It's looking like the few things that I failed to do likely re-contaminated the trans:
1) did not disassemble pump and inspect for blockage
2) did not clean cooler and lines
3) did not replace torque converter

Each of these things I recall thinking that it wasn't necessary as I had found the failure points, and didn't have siginificant metal shavings present. As it turns out, this was likely a mistake. This is a hard lesson learned - if you want it to last, there is no cutting corners.

Yeah the ATSG manuals just take bits and pieces from the factory service manual. Definitely not a step by step and parts are updated continually and procedures change. It's hard for me to keep up. Times sure have changed from the 350s and C-4s. The link you sent for converter looks ok. I am lucky to have a company that is local (well 90 miles away) but they deliver and will build any type of converter and have had great success from them. You have to have a lot of faith in a converter supplier that actually puts inside what they tell you they do. Years ago I had a bad time with DACCO converters and have never gone back. Just my experience. The drilling a hole and flushing worked on converters that did not have lock up clutch or clutches inside. I had a machine that was built just for that purpose.That friction wears the same as is in the transmission . I also sent you a PM.

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I did some more reading as to the best practices for cleaning trans parts. It seems like the most common solvents are brake cleaner and mineral spirits. Some even suggest that no towels be used at all, only solvent and brushes. A final go-by with compressed air also seems to be a good practice. I was certainly not that careful in this regard last time - I cleaned everything with shop towels. Live and learn.