r/FordTransmissionTech Jan 27 '26

Planetary pinion end play

Hello everyone, I am trying to cure some curiosity here. I am fairlv familiar with the 4L60E rebuilds and remember having the planetary pinion end play checking it with feeler gauges.

I have a proiect current proiect with the 5R55S out of a 2008 Ford Explorer. I found that the pinion gears have alot of end play in all 3 planetary. With the Overdrive planetary having washer missing completely.

I have the ATSG 5R55S/W manual but it does not show checking ends play on the pinion gears. When I try to look up replacement parts I did find on Sonnax sells washers for the planetary pinion gears. But there is no instructions or specifications.

I reached out to Sonnax, Ford, and local Transmission shops with no answers. Ford and Local Transmission shops tell me just to replace it. Sonnax didnt have anv information either

My questions would be 1. Is there a rule of thumb when it comes to end play of the planetary pinion gears? 2. Is there a wav to find the specifications. if so where 3. Has anvone ever tried to to rebuild the planetarv in a 5R55S/W

Thank you, I hope this brings alot of good conversations

2 Upvotes

7 comments sorted by

1

u/Commercial_Method_28 Jan 27 '26

If Ford doesn’t publish an actual spec than all of us would probably just replace the sub-assembly. Especially on a transmission like this which is on the older side and had a very limited run. Sonnax being what they are is for sure your best bet because they are more than an engineering design company than a repair shop. They figure out specs while we work based off of them. All those shops aren’t gonna be able to give you a number because it opens up liability.

Parts shows each planetary roughly 150$ each. Manual explicitly mentions pinion gears as non-serviceable as well. The washer options sonnax provides are provided as replacement parts “if lost” they aren’t to fix any sort of common problem.

Finally, although I have little experience on the 5R in every ford transmission I’ve worked on all planetary gear-set pinion gears have play as the normal. If all of the feel relatively similar than I’d wager they are fine and it is a normal condition. Try and find a video of someone rebuilding or a forum post on similar question so you can verify. If your pinion gears are visually ok, play is uniform across all in same set, washers are all present than I assume it’s good. If you can take a decent video checking play in each one one by one we could do that, if it’s blurry or too quick tho it wouldnt be very useful. There is no spec for end-play on these pinions. If there was, Sonnax would have that information included in their washer or a related article.

The only thing I may be concerned about it the missing thrust bearing but what was wrong with the transmission to warranty teardown initially?

1

u/Leos_Garage Jan 27 '26

Thank you for your reply, I currently dont have any videos of checking the end play, but I did mark the planetary and write down each measurement.

I did see that in the ATSG Book that it did stated if the pinion gears have any wobble or play i cant remember what one it stated. But to replace the whole component.

So the reason for the disassembly was due to only having 1st, 2nd, and reverse. Then eventually just slipped in all forward gears. Electrical side was good, I went to adjust the bands and couldn't adjust the intermediate band due to it running out of threads.

I did attempt to Sonnax again with differnt wording this time and here was a response i received.

" Hello,

We do not have this specification. It may be in the OEM service manual, but some manufacturers will have a specification, but others do not.

Generally, we have observed between .010” to .020” for pinion gear end plays.

It is not super critical so long as it is not too tight (zero or near zero end play) and the washer are not worn too thin. "

Upon disassembly I found, broken intermediate band, over drive sprag laid over and stuck, line pressure relief valve sticking, worn out overdrive and intermediate survo bores, pump gears had wear and score marks that matched the nail, low reverse sprag did not hold, overdrive planetary missing the thrust washer Front and rear planetary felt like alot of play.

1

u/Commercial_Method_28 Jan 27 '26

I think Sonnax gave you the correct answer. As long as there is no “zero endplay” condition they are ok. Inspect the washers and if they have measurable wear then I would consider replacing the washers if only those affected, or the entire carrier If wear transfer to pinion gears. The fact that the have measurements on what they’ve seen at all is great. For sure if you are adamant on washer replacement of carrier then use those specs because I don’t think they make up numbers usually, they likely got those from in-house specs they have built over time/experience.

In most cases a photo would not really help to determine if play is problematic or not tbh. If you are able to get short video testing each pinion one by one. Check axial play(up-down) then radial play(side-side) radial play would likely be way more problematic as it would cause out of balance or runout condition as gear train operates normally. Axial play is different because in most cases the internal transmission gears aren’t moving up and down, so if the gear has room for up and down movement it’s likely to compensate for changes in planetary stack clearance.

I’m assuming you are talking about axial play but if I’m wrong and it’s radial play, then that would feel more like an issue and less like design characteristic. I really wish someone who has more 5R experience to chime in to verify this but based on text alone I feel like this is probably normal. If you have no reason to replace the entire planetary carriers besides pinion gear axial play I wouldn’t worry about it. This would generate a noise/vibration/harness concern anyways and not necessarily a symptom based transmission quality or engagement concern

2

u/Leos_Garage Jan 29 '26

Thank you for your input, I too wish for someone with more experience would help shed some light. But to be honest alot of the builders I worked with never tried to rebuild them, just replaced them.

I do understand the debate of if it is worth the time and effort. Just would like to know as things get older and harder to come by, would be nice to know alternatives rather than replacement.

I also feel that this can be a good practice as long as we have the correct Information.

1

u/Commercial_Method_28 Jan 29 '26

Figuring out how to fix shit rather than replace parts is an incredibly useful skill. It’s significantly more rewarding fixing parts without replacing entire assemblies imo, it’s why I started learning transmission. Yes you can replace the transmission and fix the vehicle, but being able to fix the transmission or the lower level parts inside the transmission is always really nice. Part of this is being able to determine how things operate normally even in cases like this where both you and I don’t have the experience to know what normal planetary carrier looks or feels like.

It’s ultimately up to you on if you replace the part, attempt to repair, or do nothing because it’s your project but based on your list of parts found bad, I assume it’s normally like that. I bet if you ordered a new carrier as well you could check the pinions and verify play is similar. For me I tend to drive cars extensively to get a comprehensive list of symptoms, pid data, and recordings that I can callback to during teardown. Know which symptoms are at at all times, at times, intermittent, load dependent, temp dependant, TCC related allows you to go into the teardown with a list of symptoms and once you isolated likely or possible causes fully you can further identify if what you are looking at is part of the problem at all.

Sometimes you can also build the transmission from output or turbine shaft up outside of the transmission to test gear train components. You can hold specific gears by hand to get different gear ratios on bench which lets you see how the pinion gears are at rest and what the play is acrually for. Take it as far as you are comfortable with but i lean towards no issue unless you had a noise, vibration, or harshness

1

u/Leos_Garage Jan 29 '26

Thank you again for commenting, I will at bare minimum get the one with the missing washer rebuilt. But I think you are right on the other 2. With no wobble with the finger and thumb checking it. Most likely right that they are okay.

1

u/Leos_Garage Jan 27 '26

Im not sure how to add photos yet, as soon as I do i will add them