Clutch or Transmission?

[KyeR]

I was recently given my moms 2012 Fista Se. Its automatic (at least i have no gear shiter). Wonderful car. ~178,000 miles on it. I love this car.

However im having some troubles. Im not a very car savvy person but im trying to learn.
The car shudders and almost grinds when accelerating. Mostly around 40-46 mph, and accelerating from a stop.
My father is a mechanic at his own shop, and an ex ford mechanic. He told me its the clutch chattering, and will need replaced soon.
However i took it into my local small shop for some unrelated stuff, and they told m my 'transmission is slipping in all stages of acceleration and deceleration'

Ive never felt a trans slip before, but im not losing power, and its not failing to shift. It just shudders? I was given the advice by my mom to gun it past the ranges in which it has problems. She said its had this issue for years, and it hasnt gotten any worse recently. (Though for some odd reason it seemed to get better for a bit after i got my tires changed)

I do plan on having it fixed regardless. It might just have to wait a little bit. But whats the most likley issue/explination? Is there an estimated price i should be expecting to get this issue fixed? Is there something that i can do to either fix it, or make it stable to drive until i can aford repairs? Or is it even worth fixing? I was given the car for free so i dont mind spending some money, but im not the most well off.

 

[Handy Andy]

Shuddering can be caused by many events - when you look at this design to make a manual transmission act like an auto - you can see that it takes a bit of finesse in the mechanics - into making a manual mimic an automatic using just a clutch and a series of servos staged to "touch" the plate and then also allow the plate and clutch itself to make contact - correctly, each time - much like threading a needle - getting it to accelerate and get it right every time.

It is sad to see where the effort tends to fail once the assembly begins to reach the end of it's useful life. The region that is causing the shudder is in the clutch and the flywheel plate - the servos are sandwiched between and due to a calibration problem (the ends of two extremes) that the grab of the clutch and the throw of the servos is at a point where the vehicle appears to shudder - its caused by that wearing of the clutch and it's plate - and the servos using their sensors - are not quite able to smooth out the grabbing due to the wear generates a level of free play in the system, so a bit of "overthrow" and "underthrow" is occurring - you feel this as shudder.

The shudder will get worse over time and you may even have to force it to re-arrange itself by starting out in low (the "L" in the PRNDL) on occasion so it's not getting too lazy in thinking it can stay in higher gears and just bump the servos to move as you accelerate - then you know it's getting closer to replace the box - time. Just remember you DO have to bump the shifter up once the LOW gear range is needed to go higher in gear

• - if you do this often enough you can use this method to help you in slippery conditions to let you obtain some speed to walk out and then bump the shifter up into Drive to let the system take over and gain speed.

It does make for a good study if you have moments in which to dwell on such things...

What makes this a fascinating study is how this was accomplished using speed sensors - variable resistor array - steeper motors and the gearing ratios used in the gearbox being chosen to allow the 6 gears to mesh and interact far faster than a human could. So this effort, along with those of the Formula 1 racing endeavors - using the slapstick and electronic gearing and shuffle "box" - rivals if not equals - the fuel delivery changeover from the Carburetor to Electronic fuel injection.

As far as "estimates" those results vary with the type of transmission - rebuilt, junkyard swapout or New - with the New obviously taking precedence of cost and drop in feasibility as well as ease to swap - being the highest cost of nearly $5,000 USD in some shops onto a simple drop and swap of the pull from a junkyard - might get away with a low as $500 if no more than a $1,000 in USD - but that's if the kids doing it are motivated - in all efforts to fix this.