Hello,
Sorry to revive the thread AGAIN, but I as well as probably quite a few others that come across this thread would really love to find an answer. I'm sadly becoming discouraged that there is even a fix.
I bought a 2013 Ford Fusion Titanium about 2, maybe 2 and a half years ago @ 61,000 miles. When I bought the car, I never really noticed a very heavy shift and needless to say I had purchased an aftermarket warranty on the car for up to 95,000 or 3 years whichever comes first. I'm currently at 103,000 miles.
From 61k -> 95k everything seemed pretty decent. At 90-92k I had to have a tensioner pully replaced, an air conditioner compressor replaced (both $1,300 total covered under the warranty thankfully), and the pesky wheel speed sensor which took a crap in the snow I believe the second winter I had it and lit up the dash like a Christmas tree (I was so upset and relieved to realize that fix only costs $100 @ fords dealerships).
Anyway long story short, warranty has run out and I am noticing very hard shifts between 1-2 and 2-3 now. I have taken it to fords dealership which usually does my oil changes for me, and asked them to diagnose this issue. We determined the CV Axel (or whatever it is somehow is connected to the transmission fluid, I'm not much knowledgeable on cars) was leaking the trans fluid and my trans fluid was low 2 quarts. They fixed that, and did a drain/refill on my transmission fluid. The shifting went away for maybe 4-7 days and then it come back.
I was fed up, so I took it to a local reputable transmission shop to diagnose if its a transmission issue. This shop had said he's confident its not a transmission issue, but more an engine miss at heavy throttle.
Now its back in the shop for a wheel bearing replacement and I asked them to really look into the shifting issue. I suggested to do a tune up and maybe change the sparks/wires/coil packs. The tech has said he sees no shifting issue except for once as it was going down a hill. I'm still pretty confused on this because it happens all of the time with me.... I start driving and my whole body gets jerked around when it shifts in those gears. This is where I am at now with this situation. Tomorrow they do the tune-up service hopefully depending on the overall cost and I will see if this fixes my issues. Any suggestions/information beyond what this post already has (which isn't too much other than to replace the transmission etc etc) would be extremely helpful.