The Garage King

The transmission can be removed without pulling the engine; however, you should use a "cherry picker" to support the engine from the lift bracket found on top of the engine, then disconnect the motor-mount on the passenger side of the engine bay. This allows the 1/4" movement (towards the passenger side) you will need to get the transmission out. Unlike the Ford Fusion Hybrid, Ford engineers did not leave enough space in the engine bay to allow safe removal of the transmission with the engine fully-installed. It is literally that tight in the C-Max engine bay, and that is why Hybrid & Electric Car Sales out of Franklin, TN, charges $500 more than the identical FH35 transmission repair service, compared to the Fusion. If anyone wants to attempt a repair of their HF35, I'm happy to share what I learned going through the entire process, in my garage, with the help of none other than my amazing brother-in-law, Steve.

We finally removed and split-open the HF35 in our 2013 C-Max Energi after 222,500 miles. The "grinding" noise had started ~6 months prior (~12,000 miles prior). This is the first serious problem we have had with this car since new. NOTE: I had changed the transmission fluid twice (first time @ 99,659 miles, the second time @ 200,657 miles). The interval recommended by Ford in the owners manual is every 150,000 miles(!). Three of the four roller bearings in our HF35 had severe spalling. I replaced all four roller bearings as well as the pump filter. In hindsight, I wish I had changed the transmission fluid every 50,000 miles; maybe that would have extended the life, maybe a lot, maybe a small amount. I think 100,000 miles was asking too much out of Mercon LV in the HF35 application, let alone 150,000 miles which Ford recommended. We ordered a 2025 Ford Maverick Hybrid (CVT), and I'll be replacing the transmission fluid every 50,000 miles, religiously. I have about ~$250.00 into repairing the HF35 in our C-Max. Transmission has been reinstalled and car has been test-driven: No more grinding noise. Hoping to get another 100,000 miles out of this car. If you are mechanically-inclined, have a "cherry-picker", transmission jack, and are willing to spend ~$100 on bearing puller tools (if you don't already own them), this can be done with the help of a second mechanically-inclined friend/relative, and not that much $$...

I just "rebuilt" the HF35 in our 2013 C-Max Energi (222,5000 miles) in that we replaced all four roller bearings, which were badly spalled. We did not index-mark any of the gears, and since they are all concentrically uniform, I can't forsee any issues. Learned a LOT from this process. If I could find all of the related torque-values somewhere, I could start a side-hustle. NOTE: Be sure to buy Ford-branded bearings. I didn't, and the BT4Z-4221-A equivalent I had purchased would not seat on the gearshaft, even using a 20-ton press. Removed that POS and replaced it with a new Ford P/N BT4Z-4221-A, and it dropped right on (heat bearing to 375 degrees F in an oven and chill the gearshaft with a chunk of dry-ice, for 30 minutes.