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What is this broken part in my transmission/OD?

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K

kozelding

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My overdrive has started to lose pressure (again) when hot. I pulled off the cover to the accumulator, and out flowed a sea of metal shavings along with this....


My transmission was "rebuilt" < 10k miles ago, and I've always noticed a good amount of metal shavings (steel and brass) in the oil before now - but nothing quite this large.
 

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That is the overdrive bronze thrust washer. Moss lists it as 866-560. It is pretty troubling that it's broken because I can't think of a mechanism that would do that. I think you're going to have to pull it apart again.
 
That washer isn't really a wear item. I suspect your overdrive was improperly shimmed at the last rebuild and you didn't have the proper clearances. It was probably too tight. You are almost certainly going to have to remove the overdrive from the tranny but accessing it shouldn't mean and complete stripdown of the overdrive. The question is whether there could be more damage from the too-tight clearances hidden inside. At a minimum I wouldn't take it back to that shop.
 
Ah, thank you so much - I see it matches the Moss photo too.

I have to admit part of me was tempted to clear out the shavings from the ball valves and accumulator and hope for the best, but I see now that would be asking for serious trouble.... I have noticed an occasional "thrum" at low speeds (40-45 MPH) with the OD engaged, so there have been other clues that not everything is healthy.
 
Its possible ???? That when they mated the OD to the transmission it was not done carefully enough and the thrust washer was broken due to misalignment during assembly and it was just a matter if time before it failed .
When you mate OD to transmission everything has to line up perfectly (yes even the stars) as well . You cant force anything or you will bend break twist or generally F something up .
 
Bob_Spidell said:
Here's what mine looked like after 200K miles (the OD worked fine when removed):

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View attachment 59821
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I don't think it is the one at the one-way clutch/annalus gear, I think it is this__much more fragile__one, between the sun and planetary gear set.

IMG_7157.jpg


Note: it is bronze, I just have applied a dry-film lubricant polymer coating on it.
 
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