Unknown plug or piston 4R75E

[TommyJoe]

My wife's 2005 Expy lost 1st and 2nd gear. Trans shop said fried, 2400 to rebuild.
It is now on my bench. Re-Build many of trans over the last 40 years and I have a dilemma.

I am sure because it was build on 01-02-2005 that might be the jinx.

As I removed the trans pan, a piston or plug fell from the pan. I think it is a plug because I find no holes
that it fits in except for the dipstick tube hole.

I have seen this before but this is my first 4R75E that I am rebuilding.

Any ideas before I continue.

 

[collazoscesar]

They told me when the trucks were built they let that plug fall into the pan. I drove myself crazy trying to figure what it was..it's nothing...its from production and a plug from the dipstick.

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[TommyJoe]

That is what I figured, they had the trans already primed and the torque filled and the dipstick went in from the top.
Just wanted to ease my fears.

Thanks Much!

 

[Bain64]

Plug is from factory just like collazoscesar said. It means the pan was never dropped until now, possible the transmission was under-serviced over the last 13 years.

 

[1955moose]

Ok I'm not a big tranny expert, but have rebuilt my share in my day, and took a trans class in my early days, mid 70's. Why would Ford make an item that just lays in an oil pan of transmission? That's kinda asking for trouble bobbing around in there. What's the logic there? Betting burned clutch plates and band, for no shift Condition! Let us know what you replaced?

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[Bain64]

Moose, I agree it's quite strange! My understanding is that the plug keeps contaminants out of the transmission via the dipstick tube hole before fluid (or maybe the dipstick tube) is added. FordTechMakuloco explains it in one of his transmission videos.

 

[1955moose]

So its at the end of the tube? The 05 uses a regular dipstick that extends into the pan, I still don't get where it's plugged into? Seems kinda weird, but that's Ford for ya.

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[TommyJoe]

Called a Ford Trany Tech and he said that is exactly what it is, might have even been put back in at service. Stupid but it is a EXPY.
Found my trans problem, a common failure, I think it should be a recall item from how many of the input drums fail because of the
cheap design. Here is a picture of the fail point. Causes loss of plate contact and not friction!

 

[blue oval guy]

Is that a weld failure on the outer edge? how does that separate on that input drum? I have never see that.

Thanks

 

[TommyJoe]

I am told several thing, one is extreme pressure, two poor design, three poor design, four poor design!
4 out of 5 techs that I have talked to says poor design..
Just for information, the trans was re-inserted today. after replacing the drum and some misc bearings, it drives great. It is the original Transmission and engine. Has been serviced carefully as the original purchaser was a traveling sales person. My wife out approx 60k miles on it and then the failure.