Gearbox change difficulty?

Not really as long as you understand that this is a CVT that doesn't shift so I'm not sure what kind of shifting you're looking for sounds to me you like maybe having a problem with the mating of the engine to the electric motor so the engine is become weak or the electric motors become weak and there are problems matching the two gear wise driving wise not as in putting them together changing the transmission is very straightforward to fall out right on your head You mean you know it's just like any other automatic in the front wheel drive car take a Corolla a Nissan same other than removing a high voltage safety plug in the back and undoing a few sets of orange wire finger plugs that go in the transmission and they're bolted other than that there's the bolts going around the transmission You don't have to remove any flex plate or drive plate bolts as it just slides in so when the last bolt comes out of the transmission it can be ready to rip right out or fall out as the case may be so beware of that It is pretty straightforward and for aussie people that are on my toy mods list this would be a walk in the park on a morning.

 

If you have experience swapping engines, you won’t find it difficult

 

How did you arrive at "my gearbox is ill?" These things rarely go bad and junkyards are filled with unwanted gearboxes.

 

You don't really "remove MG1" or "remove MG2"; those are both inside the transmission and you just remove the whole thing from the engine. It's hella heavy for a transmission, something like twice the engine, largely because of the two MGs inside.

Maybe you meant remove the big orange cables that connect MG1 and MG2. Yeah, you do remove those.

 

My thought as well... If someone thinks they have a problem with a Gen1 transmisison, there's some history to that. But if someone has problems with a Gen2 or Gen3 transmission first thing I'm going to say is whoever did their diagnosis doesn't have enough experience to come to that conclusion. And because @deis doesn't offer any details as to how the diagnosis was done, let alone the symptoms that started the diagnosis, I'm fairly certain that once they swap the transmisison, they'll still have the same problem, unless it's just the transmission dampener which is a common problem on Gen3 when the owner ignores the rough running from a headgasket failure.

 

No I'm in the same boat as you was with the 2013 engine in isolation runs absolutely perfectly's as smooth as glass It's a JDM spec engine that are replaced a blown US spec engine and I mean it rattled itself to death couldn't save the parts. The transmission I don't know how to make that work in isolation because anytime their car is moving forward the reciprocating mass is turning whether you're in drive or neutral etc I'm not sure if I'm dealing with damper springs or what but I thought for about 3 months now the transmission's going to have to come out I have my old flex plate that goes with the old transmission that's sitting right here staring at me It had 235,000 mi on it. I ordered a transmission along with the engine when I bought it from out of country you know those 65 plus thousand mile things I thought it would be smart to have a transmission about the same mileage as the engine rather than a transmission with near 300K on it maybe I made a mistake I don't know I did use the torque plate that came with the newer engine. It looked newer than mine so I thought what the heck. I can tell you the throttle body that came with the engine was toast and gave me all kinds of codes and the coils that came with the replacement engine all those came out I put mine in course new spark plugs. So I'm back to this noise that's when I'm outside of the car and the person sitting in the car makes it happen that noise is right in between the engine and transmission your eyes go right to that space where the fat metal water pipe comes straight out of the back of the head about where the drivers gas foot when it's on the gas would be if you drove a straight line through my foot it would be going to that spot and then when I'm outside of the car that's what I'm looking at and touching and you can see the engine spinning over and running and it's not missing a beat even while the rattling and clanking is happening the engine is solid and stable there's no way it's because the fires getting put out or there's a misfire this is like some serious imbalance whether it's between the electric motor and the gas engine or something more than anything it really pisses me off I don't really care about this car I got five other ones that are worthy and worthwhile and you know my old lady wants to work on this piece of garbage kind of maddening but she's learned now she's figured out that the generation 3 isn't squat some people it takes longer.

 

The transaxle damper plate tends to break springs when (incompressible) coolant is leaking past the head gasket. There’s a black plastic piece at the underside, which I think can be pulled off to view bottom of that damper plate.

has the miles on the odometer been mentioned?

 

A leak-down test is similar to compression test, but more informative, AND easier to set up with a Prius. Engine needs just to be hand-cranked, to get the various pistons to TDC on compression stroke, and when there that cylinder pressurized with a special gauge set attached. Both the gauge readings and telltale signs (air escaping) bubbling help determine if head gasket is leaking, and how. This is something a competent shop could handle, requires compressed air, that gauge set, and experience.

simpler and more easily DIY’able is a boroscope inspection of the combustion chambers, preferably with coolant system pressurized. The camera should be capable of “looking over its shoulder”, to check for coolant tears leaking past the head gasket. Also check appearance of piston tips. With head gaskets leaks on gen 3 it tends to be coolant on cyl 1, or sometimes 2, and tip of those pistons accordingly appear much cleaner, what’s been called “steam cleaned”.

 

A three as it does seem to take forever to get to operating temperature for an internal combustion engine like versus a Corolla or something with the same engine and a radiator and a water pump. My Prius and my Corolla pull up under the carport next to each other we lift the hoods under the Corolla you will see the intense heat waves wafting up off the engine. Hit you in the face like you're standing near somebody running a plasma gun or a welding torch quite warm. You lift the hood on the Prius and you don't even know the engine's been running hardly unless you put your hand over the back side of the back of the valve cover so your hand is in the way of heat rising up off the exhaust manifold and that's about it touching around on the front of the engine and what have you now you never know it

 

Those springs take a beating whenever the engine is misfiring for any reason. Because of the way the engine and the transmission in a Prius interact, any cause of engine misfiring results in horrendous clatter from the gear train and eventual clobbering of the springs in the damper (which just makes the clatter even worse).

It is good every now and then to remember this classic article about a Prius that was let go for scrap price because of such a horrendous clatter, the result of misfires eventually traced to a single spark plug.

https://www.aecs.net/techniek2012/March%20prius.pdf

 

True, mustn’t jump to conclusions.

 

I said TDC, and was a little reluctant as I typed; acronyms can be obscure. It stands for Top Dead Centre. Again, a competent shop would know this stuff.

 

And how is it discovered that this car was sent away to the junkyard with a misfire the junkyard guy changed the plug and kept the car? I wish my car was as simple as a one bad spark plug hell even two I can't just keep changing them forever and hoping no misfire codes engine hand on top of it while the cladders going on the engine spinning away like it should be I guess I'd say and it's shutting off and turning back on like it's supposed to seemingly I just have this rattle that I can step right through with the gas pedal It's only going on in that middle wide band not in the red not down in the electric but right there in the middle It was clatters away You step through it get it to the red portion clatter gone. If you don't want to do the leak down test take the tray out pull the spark plugs out even a cheap camera looking up in there especially like an hour after a good run shut down let it sit Do the disassembly you're degas bottle and cooling system. Is under decent pressure by the time you're disassembled have the coils and plugs out and ready to shove the camera in droplets of water should already be forming in the cylinder of the misfire and you should readily see it then that should pretty much end all of the discussion I guess. Usually the kind of guys performing leak down tests are your folks that really know what they're doing they're not out to generally rob you out of a bunch of money or anything they're just performing this leak down test whoever's test it is however it works The snap-on version whatever and that's that they give you the results. Then from the time you received the results to getting around making an executive decision could be weeks if you have more vehicles than you know what to do with maybe never The mechanic in the shop don't care. Inspection cameras now are cheap can be borrowed from AutoZone too I think nowadays so and both operations are going to require the spark plugs to come out.

 

If you don't read the linked article, maybe you'll never know!

But yeah, it was pretty much that, with a few more steps.

 

I think I did read this article or the pages or the post when you posted it to somebody else the first time I don't remember all the particulars except obviously they sent the car away for a bad plug well we've put in two or three sets just messing around to see we don't think we have fake or bad plugs and the engine just is running smooth as all get out even while it's making the racket the engine well there's a video I posted on YouTube but some people have seen I guess The engine you can put your hand on it it's just running smooth while the clanking and cutting up is going on and then my video your eyes are drawn right down there to the water inlet or outlet on the back of the head where the transmission is connected to the engine.