I will be meeting with a key designer/engineer of 5R55s

I am in school to become a licensed mechanical engineer. A key engineer that formally worked for Ford in the design of the 5R55E teaches sophomore classes at my college.

I have always been enthuestic about the design of the automatic transmissions and was excited to learn that he teaches at my college.

I am planning on going into his office and asking him a list of question I have for him concerning the design and development of the 5R55s. If anyone wants me to ask him a question concerning the design and development of the transmission, such as "why was this done", "why did you not to this way", etc. post here and I will ask him when I visit him and reply.

Thanks.

I suppose a " wth can you do to keep these things from going to crap" would be a good start. There seems to be so many Explorers with 5R55E transmission failures when you can neglect/dog/abuse a 4R70W and they run on forever.........

best operating temperature?

The external cooling loop begins opening when the internal fluid temperature reaches 150 degrees. What is the optimum temperature range for best fuel economy, performance and durability?

Could we be working on a new Podcast?

Who thought tool steel gliding on soft aluminum was a good idea?

i had mine rebuilt and everything tests fine but i still keep getting the p0741 trouble code.
the transmission shop that rebuilt it swears that everythign tests fine. why is my O/D light still flashing at me then?

I'd be interested to learn more about how the cooling circuit of the 5r55s works.

What temp does it begin circulating fluid to the cooler?

Does it circulate fluid when the trans is running in OD?

What is the normal operating range that the trans was designed for? Mine runs between 150-170...but one time during heavy mountain driving it hit 190.

fair question...

ncranchero said:

I suppose a " wth can you do to keep these things from going to crap" would be a good start. There seems to be so many Explorers with 5R55E transmission failures when you can neglect/dog/abuse a 4R70W and they run on forever.........

Click to expand...

Though this seems a tough or unfair question at first blush I like it. The answer could be as simple as economics. Had to go lighter for weight savings (equals MPG economy), cheaper metallurgy inside, space/size change....lots of reasons.

It may be anecdotal evidence that the 4R70W is better but if that is what people percieve then they see it as their reality. Please find out why a new transmission was designed to replace the 4R70W.

The thing to remember in talking auto tranny design is the COST. The 4R70W started out of a robust transmission in it's own right. Became a darling in racing so LOTS of highpower mods available, etc.

The 5R55 started out of the C-3 Pinto transmission. Never a darling of anyone, no high power mods, etc.

From scratch, a new auto tranny costs hundreds (HUNDREDS) of millions of dollars to design and tool into prooduction. Wonder why we keep getting "re-treads" with wing ding mods to up or improve this or that? A lot of design work is fixing prior design upgrade shortcomings (like the servo pistons in the A4LD/44/55E/W/S etc..)

You're meeting the 5r55e designer? Punch him in the face for me.

Not really...lol

Did the engineer ever bother to answer any of these questions? Not much point to the thread if he didnt

Hitch: Some of these transmissions depend on a one-way clutch to provide ALL driving effort in some gears. One does so in "top" gear, O/D.

Please ask him if you can, what sense such a design foible makes. imp

So this post just died?

Rcodenewf said:

So this post just died?

Click to expand...

I think the OP was having a dream when he posted...

Totally. Or too ashamed.

Gotta admit it DID bring out a lot of comment on these damned transmissions!

Maybe I'll try this technique in one of my other forums.......imp