Oil pressure warning despite the oil being full

Neat article! That's just for shock absorption. It was in one of the Weber videos -- gen 2 I think. I haven't seen anything that would break or slip other than the short amount of travel in that "clutch."

 

Search this site for "torque damper". I believe it is on the ICE shaft, and will prevent a complete lockup from rippling through the rest of the drivetrain.

 

@GotToMakeItTo275K I bet one of the moderators could help you change your username to MadeItTo274K, wouldn't even cost anything

 

It has more "travel" than you might be giving it credit for.



It really is built like any manual tranny clutch you might have seen: that is a friction-faced disc, sandwiched between a springy pressure plate and the flywheel. The only thing missing is a release lever to relax the pressure plate and disengage it. So the disc is always under pressure. But if you give it a good enough reason to slip, it'll slip.

The little coil springs surrounding the center of the disc are just there to absorb little bounces. All my past manual tranny clutch discs had those, too.

Edit: I think one other thing 'missing' compared to a manual tranny clutch is a pilot bearing in the center of the crank/flywheel. Maybe they decided none would be necessary as there's never supposed to be any relative rotation other than very rare slippage. The lack of a pilot bearing is probably why so many people happily report doing engine swaps and never mention needing a pilot tool to get the engine and tranny to mate back up.

 

Most of cars with manual transmission and transverse mounted engine don't use pilot bearings. Pilot bearing is not really needed if you don't have the short input shaft like (most of) manual transmissions on cars with longitudinally mounted engines.

Clutch alignment tool is only used when clutch (in a Prius torque damper and limiter) is installed. People don't need the tool because they just use the disc that came with the engine. But you actually don't necessarily even need the tool when replacing the disc. I've replaced clutch discs without the tool on some other cars.

 

I guess I've been reading the Gen 4 -> 3 engine swaps, where people are changing the flywheel.

I've replaced clutch discs without a pilot tool in my past life, thinking "that was easy!" and coming to regret it later in the job when I've got all three of my hands occupied trying to coax the transmission back up to the engine and it stops like there's a brick wall there. Which is why I keep reading about these trouble-free Prius swaps and thinking, kids these days, got it so easy.

 

Gen 3 and gen 4 Prius have a drive plate that you can't take apart. So "clutch" disc, pressure plate, and running surface for disc are always together. So only way for it to be out of alignment is for it to be bad. Then you would just need to replace it with good one. So you will not need (and couldn't even use) alignment tools.

When I haven't had correct aliment tool I just looked very carefully to make sure the disc sit at the center. Always went together just as easy as with the alignment tool. But yes lack of pilot bearing is one thing that makes it easier. But lack of pilot bearing also makes it harder to find the correct aliment tool.

 

Thanks for the fuller explanation. I was going by the Weber Auto videos I've seen and they all seemed to imply (but not really say) that it had limited travel. But I just saw one I hadn't seen and, while he still doesn't explain it, it sounds like it works much like a regular clutch but one that never relaxes its grip. Make sense to me!

 

Interesting ... as valde3 pointed out, Gen 1 and Gen 2 had an arrangement looking very much like a traditional clutch disc with a separate pressure plate bolted over it, only the pressure plate lacks the usual disc spring fingers to make it releasable. And glory be, there is a pilot bearing or bushing (31270B):



But later on by the Prius c (which is even the same engine), they had moved to a single "damper assembly", effectively a clutch disc and pressure plate perma-squished together, and no pilot bearing, nothing to line up, just bolt on and go.