John Kelly from the WeberAuto Youtube channel explains the inner workings of the first three generations of Fords hybrid transaxles.
Contrary to popular hearsay, there are no belts, only cold steel and aluminum!

 

John Kelly's video's are amazing. Easy to spend a weekend watching him tear stuff down.

 

Toyota has the MG1 and MG2 on the same shaft which is more efficient. They also have a patent on this design so Ford and Subaru (with the Cross Tek hybrid) have to use separate shafts for MG1 and MG2

 

Apparently, Toyota decided the Ford design is better since the tranny fits into a smaller footprint and has copied it - probably due to their cross-licensing agreement on hybrid tech for a period of time? Can't easily find confirmation of that on the net.

 

Some owners are apparently experiencing bearing noise, possibly because their vehicle never had regular eCVT transmission oil changes. The videos above show a multitude of bearings that require protection to ensure a long life.
In my manual Ford indicates:

"TRANSMISSION FLUID
Checking electronically-controlled Continuously Variable
Transmission (eCVT)
The eCVT does not have an underhood transmission fluid dipstick.
Refer to your scheduled maintenance information for scheduled
intervals for fluid checks and changes. Your transmission does not
consume fluid. It is designed to be filled for life. However, the fluid level
should be checked if the transmission is not working properly, or if you
notice some sign of fluid leakage.
Transmission fluid should be checked and, if required, fluid
should be added by an authorized dealer.
Do not use supplemental transmission fluid additives, treatments or
cleaning agents. The use of these materials may affect transmission
operation and result in damage to internal transmission components"

A TSB, technical service bulletin may have updated this original guidance that it is filled for life with a recommendation to change the fluid but I could not find one. The drain plug was not magnetized on our 2010 to collect swarf which I found disappointing. I will stick a small supermagnet on the outside end when I get a chance.

 

It's like anything else with bearings, lots of gears and two electric motors inside it: once the fluid that lubricates all those parts begins to break down with age, the lubrication suffers and the components begin to eat themselves up. This is an engineering reality as old as the ages which only began to be approached scientifically around the late 1800s. From Ford's perspective in this case, hopefully by the time the vehicle is out of warranty. Ford worded the manual carefully to avoid liability. The design itself is very good - even excellent - but Ford didn't make the maintenance obvious, and didn't want to tell people they could do it themselves. At least they left the drain and fill plugs in an accessible place. They didn't want anyone cracking these transmissions open to maintain them. If I was a Ford attorney, I'd give them a 10 out of 10 for their guidance. The attorneys help write the manuals, and their job is to protect the company from liability claims. Also, since these transmissions were designed by Aisin, all the lawyers have to think about the problem of international litigation. All these cars are the same way to one degree or another.

Check out Kelly's video on the Nissan Leaf vs. the Chevy Bolt/Volt. He actually reads from the manual and has to basically stop himself from laughing in a couple of places.

 

Also: It's fascinating to me that if you go out to 27:45 or so he talks about the hydraulic clutch in the first generation but doesn't have any idea what it does! It's got a hydraulic clutch in there with no fluid passages and apparently no reason to exist, and wasn't continued on the later generations, but it's riding around inside there for some reason or another.

 

Having a drain and fill plug is almost a luxury these days! I recall when I bought my Volvo many years ago, they had a free 2000km oil change which included the engine, transmission and differential. The transmission and differential had magnetized drain plugs too and I can vouch for the fact they worked!!!!! WOW!!!! On our 2010 Ford escape, someone cut a large hole in the inner fender liner to access the fill plug. Only problem is that it's in the wrong spot!. Too bad they didn't see the prescribed cutout hole marks Ford had printed on the inner fender beside where they cut. I didn't want to cut another hole since the inner liner would look like swiss cheese. Still, another little known secret tip every DIY owner should know about.

 

Yes indeed, and I suppose we should count ourselves lucky. That's why it's so important for the "good guys" like FTMakuloco, John Kelly, yourself, and some of the other people on this forum who go out of their way to help people out. FTM has a video about the liquid-cooled PTUs (power transfer units == transfer case) on their AWDs which have the PTU buried in such an inaccessible spot you need investigators from Scotland Yard to figure out where it is and then get creative in order to change the fluid. And even with the liquid cooling he says the lubricant breaks down after 20-30,000 miles and needs to be changed, or they grind themselves up. Maintenance records are a big deal, especially on any complex vehicle like these.

 

Prof Kelly is the main man!!! Just goes to show you that despite the simplicity of an EV, most owners live in ignorance of what's good, bad and ugly and the car companies AINT helping. I wonder what Tesla is doing in this area - owner's manual, do they have a heating/cooling system etc.....