5R55E Reverse piston damage

[cr125r847]

This is my first try posting pics, so work with me if they do not show up.

I'm rebuilding a 5R55E from a 1999 explorer and wanted to share something interesting that I have found inside:

This pic is the end of the reverse servo piston shaft. The end of the shaft is almost completely chipped away, which ended up causing the transmission to go bad and many hard parts to get wrecked.


I bought a used reverse piston off Ebay and received this:

The end of this shaft is pitted and cracking, just like the one that was originally in the transmission.
I just wanted to give everyone a heads up to very closely inspect all of the parts that go back into the transmission when rebuilding it. Damaged parts like this could easily go unnoticed and cause the transmission to fail soon after rebuild.

One question that I have though, is some of the exploded diagrams of the 5R transmission show a spring under the reverse servo piston and some with no spring. Anyone have any information on this?

 

[BrooklynBay]

The spring was used in the A4LD.

 

[cr125r847]

Do you have idea why the spring is no longer needed?

 

[BrooklynBay]

The spring helped pull the piston back. The electronic valve bodies have a different fluid map compared to the A4LD so maybe they felt that the spring action of the band with gravity would be enough to pull the servo back. I guess the fluid could also push it back if it gets directed into the opposite side of the servo.

 

[cr125r847]

That makes sense.
I think the hardest part about rebuilding the transmission is figuring out what parts to order when replacements are needed. Ford has made a lot of changes to the internals.

 

[BrooklynBay]

This is one reason why rebuilders have such difficulty with them. Almost every year has some sort of production change (seal sizes, seal materials, numerous center support variations, different torque converters, shaft lengths, servo piston shaft lengths, thrust washer thicknesses, torrington bearing updates, check ball configurations, valve body variations, gasket thicknesses, bolt lengths, seal depth, solenoid production changes, servo & cap sizes, modulators on the older models, modulator pin lengths, clutch pack plate numbers, TRS & DTRS, etc). I'm sure that there are even more things than this.

 

[Cobraguy]

That's also why a factory Ford reman trans is hard to beat. They get all the latest updates.

 

[BrooklynBay]

I once bought a factory remanufactured transmission, and it was a soft parts rebuild. It was an 88 transmission with 86 & 87 hard parts. It had no updates at all. The transmission had problems from the beginning, and even though it was under a 1 year warranty, they did nothing for me. It failed in less than a year, and I had to rebuild it. I'm not saying that all of them are like this, just that this was the first, and last time that I will buy one from Ford based on my previous experience.

 

[cr125r847]

That is the reason I'm rebuilding mine. It is taking me a lot longer to rebuild the transmission myself, but I am making sure the correct things are getting done to the transmission.
It's really a learning process though.

 

[cr125r847]

I looked at another servo piston shaft today and saw the same pitting and cracking on the edges, like the second picture above shows.
I ended up ordering a new one, which only cost $10.
This is probably a part that should be automatically replaced when rebuilding this transmission.

 

[BrooklynBay]

Where did you order a new one from? Was it on EBay?

 

[cr125r847]

I had the guy at a tranny shop in town order it, so I'm not sure. It is not from Ford though.
I figure if the Ford shafts crack like this, a different company's product can't be any worse.

I'm picking it up on Wednesday, so I'll find out then.
The other thing I found out about the shaft is they come in different lengths that are specified based on the number of notches on the shaft. Mine is a 1 notch.

 

[BrooklynBay]

Compare both of them when you get it to make sure that it's the correct one. I would recommend using the TransTec Vition D ring kit instead of the standard O rings.

 

[cr125r847]

Another thing, I think I'm done buying used parts off Ebay. Most of the parts that I received were for an a4ld and the piston shaft was cracked. The guy is sending the correct parts out asap, but this wouldn't have happened if I could have inspected the parts before buying them.
I could have obtained all of these parts locally for a lot cheaper.
Live and learn...

 

[cr125r847]

The rebuild kit that I bought has a lot of Transtec parts in it. I'll have to check if I got the D ring.