broken transmission input shaft

I've not worked on this directly, but usually a rough running Gen3 due to headgasket failure will destroy the dampener plate in the transmission if the bad engine is driven for too long and this looks like it was taken to the next level. Many times we've talked about how the electric motors are powerful enough to snap the drive line, but this is the first time I've seen a picture of it.

Next step is to figure out if you're gonna have to replace the whole transmisison or a component within it by watching this video where they take apart the transmisison and explain all its components.

 

What's the miles, have you ever cleaned the EGR circuit and intake manifold, and if so at what miles?

First two links in my signature have more info. On a phone turn it landscape.

 

A rough running misfiring engine due to any cause will do that.

First it will make awful clattering noises in the transmission as it bounces the damper against the shock absorbing springs that protect it.

After driving long enough like that, the springs fall into pieces that you can scoop out the bottom of the transmission bell housing, and the clattering noises get even more awful because the damper plates are flat-out slamming their limits of travel with no springs there to protect them.

The power of the electric motors isn't really a factor. The mass of those motor rotors, along with the rest of the gearing, is enough to do the trick. Every slam of the springless damper plate against one limit of travel or the other pits the poor input shaft against all of that inertial mass.

Snap.

 

Yes, but the real question not yet answered is how much of the transmission has to be replaced when you have a snapped shaft in this particular location?

 

OP didn't mention the year. The answer to "will Toyota sell me an input shaft?" is yes; for example


2015 Toyota Prius Shaft assembly, input. Transmission, driveline - 3571047041 - Genuine Toyota Part


but the OP should be sure to look up the part number for the right year.

The answer to "do I want to take on a transmission rebuild project with a new input shaft?" might be different. It's a tedious job, and many of the bearings are preloaded by select-fit shims sold in a bunch of thicknesses. There's a slow process of test-reassembly, preload measurement, calculating and ordering the correct shims, then reassembling for real.

On the web site for Art's Automotive in Berkeley, CA, there's an old article about an old Prius transmission rebuild he did (it was a Gen 1), and why he decided not to do more of those. Part of the answer, IIRC, was that nearly all the needed shim sizes were in US warehouses and shipped right away, and then there was the one that showed up from Japan a month later.

 

you show a 2009, what year gen 3 are we talking about, and how many miles?

 

At more than $600 for a shaft assembly it seems like OP would be better off buying a replacement used transmission, which likely costs near the same and no disassembly/rebuild required.

 

while you are in there... if you want a lightened flywheel let me know... heck.. you might want the LSD, if you are feeling frisky!