Transmission input damper

Damage to any part of the damper disc leads to its further destruction. Therefore, it is unlikely that your damper problem could suddenly stop reminding you of itself.

See this topic.
Is this transaxle dead? | PriusChat

You may have other engine and transmission problems that need to be diagnosed carefully. Problems do not always come out in the form of codes. Pending codes can sleep for a long time while the engine is already in a stage requiring intervention.

 

I don't know I'd probably start first with making me sure the engine is in good shape the compression between cylinders is pretty damn close and all of that sort of stuff before I start wanting to pull the engine forward or the transmission back for sure generally a mechanic stethoscope is a good thing to be playing around with during this 20K of hoopla. Anytime you can get the stethoscope out and spend time listening and sometimes you can get right there where you need to be by listening even a long metal bar stuck on the transmission or the engine with your ear near the end of it can work stethoscope would be better but hey. I mean pulling the engine out of a generation 2 was a breeze I mean it's stupid ridiculous easy people with physical impairments can even do it that's almost like changing an engine in an Old 74 Corolla or taking it out I'd want to try and get that as sussed out as possible before I start undoing lots of engine to transmission bolts. But if the rattling comes and goes like you can drive the car a good portion of the day with nothing going on and then all of a sudden pull up to a stoplight and it starts rattling as it's idling down to shut off sounds like the engine's going to almost jump out the car? Then the torque plate would not be a suspect at this point in my mind something else is going on that's causing an imbalance that may be causing the torque plate springs to slam just while that's happening then it goes away for the day or while you're driving or whatever is going on I had a generation 3 doing this I got tired of fooling with it and just left it when the guy who has it now fixes it who I know very well if he figures out what's wrong and doesn't just change the engine I'll post it up and let everybody know as far as I know he's taking the engine and transmission out and taking the thing apart he has plenty of time.

 

Rough starts you say...

My impression is that most of the time when one hears the input damper acting up on a 2nd (or 3rd) generation Prius at startup it is because something on the engine side of it is not right, the engine isn't smooth enough, and the input damper cannot quietly absorb the difference. Best not to let that fester because (also my impression) all that abuse can eventually damage the damper, and that will be a pain to fix.

 

Internal engine problems I wouldn't expect any kind of code are you kidding me there's no way the computer can know if a rod bearing is worn or something like that not realistically yet on anything like this. But yeah absolutely that's what happening . It will surely be interesting to see pictures of what you find because I haven't really seen this on the two the three does this like all the time.

 

Used transmissions with motor generators are so numerous compared to other hybrid parts that they are handed over to scrap metal. The most reliable part of the drive. You can practice removing and disassembling the transmission. Post detailed photos and videos in this thread.

 

There is a little access window on the bottom of the car that allows a view of the damper plate. Normally there is a plastic plug in place to keep it clean. It pops out and then you can see part of the damper plate through the hole. If some of the springs have broken and fallen off the parts should be right there as it is the low point in the disk shaped cavity. Given the age of that plastic plug it is possible that it will break when it is pried off, so be prepared to buy a replacement cap.

 

Now I have to go out and look at my transmission that's out of the car there should be a place you could drill a oh I don't know quarter inch hole or something whatever you can fit that little camera doodad through I'm going to walk out there in a minute this should be doable but then you got to take it apart anyway because if it's not that it's the transmission so tada. I'm betting on internal transmission more than the flex plate at this point because if the flex plate was really damaged as in springs pieces popping out they would have been down in the bottom there some dust something sharp pieces to poke your finger whatever so we'll see when you get it separated you may have enough room with a jack under the transmission and everything more or less disconnected to pull it back just enough to stick your camera down in there but I'm imagining you're just going to see what is it the Three springs or whatever sitting in their holders there's not really any way for them to get over heated and get damaged that way so slamming and not breaking and still being intact I would think they'd be okay and then after you verify that I guess transmissions coming out rare but it happens.

 

Is it possible on this engine for the flywheel nut to be a little loose? If there is any play at all one can imagine that the flywheel might rattle a bit when the ICE starts/stops, since it could move up and down a bit on the splines, or if the splines are conical at all, it could move a tiny bit perpendicular to the shaft.

 

To be honest I'm not even sure that this car has a conventional single nut holding the flywheel on. Looking at the first few minutes of this video:

The flywheel and the damper are integrated. At 33:00 in the video, where they have the CVT taken apart, it does appear that the shaft that goes through the transmission has splines that might engage with the center hole of the flywheel. Can't tell for sure. In this video:

at 20:51 it does appear that those splines are engaged with the flywheel (both in Gen 1 and Gen 2, which are both out on the table).

Finally, in this video:

at 18:19 they show a motor just pulled from a car, with the flywheel still on the motor, and it rotates to a position and lighting where the grooves to match the spline are finally visible. So power from the flywheel/damper does seem to be transmitted using those splines to the transaxle.

What is holding the flywheel to the engine though? Looking at the manual... OK, on page EM-89 there is a diagram. The flywheel part of the flywheel/damper is attached to the motor with 6 bolts around the center hole, then the damper part of the flywheel/damper is attached to the flywheel with 6 bolts near the outer rim. So the 6 inner bolts are not visible until the unit is split into the two pieces.

And the answer is, there is not a single big nut/bolt holding this part to the motor. Seems unlikely that enough of the 6 + 6 bolts would be loose at the same time to allow the flywheel to rattle around relative to the motor. Damage to the splines interface is still possible though.

 

I've one out on ground and one in hand it mounts like a flywheel on that bolt circle

 

The damper disk springs will be destroyed faster. The splined connection fits tightly into the damper and if something in the spline starts to be destroyed, the teeth start to wear off, then the transmission will simply lose connection with the engine. There will be no return to operation. It's a one-way street.