Yaris hybrid as a motorhome towcar?

[TonyHSD]

Hi all, I have it wrong with my video example earlier, apologies, it applies for latest Prius and Corolla hybrid and seems like Yaris is completely different set up. P510 transaxle that is fitted to Yaris hybrid has a mechanical Parking brake operated with cables like standard auto and it’s possible to keep the car in N without been in ready mode, confirmed. The other major difference is that there is no coolant going through the bell housing to cool down the MG1 and MG2 stators, all is cooled down by the transmission fluid only. The major risks of towing with drive wheels on the ground I agreed with Toyota are overheating and catching fire. As you mentioned before once the car moves will generate current and where it goes I can’t certainly say but the power management device (ECU) or whatever is there actually is OFF so the current will go to inverter/converter unit and to the Battery, I think that answer the question why we can’t tow with drive wheels on the ground, it’s not because of lack of lubrication but because of extra electricity and heat generated but not managed. Maybe I am wrong but make sense to me. There a couple of examples that Tesla catches fire because of towing.

here we have the P510 transaxle explained 

Regards 

[Mike J.]

In neutral, there is no energy created, otherwise you couldn't move the car! The lack of flowing transmission oil/coolant is the issue as with older manual transmissions with oil pumps.

[Mick F]

27 minutes ago, Mike J. said:

In neutral, there is no energy created, otherwise you couldn't move the car! The lack of flowing transmission oil/coolant is the issue as with older manual transmissions with oil pumps.

This sounds right.

It's a lubrication issue, not a generation issue.

Mick.

[Mick F]

On 9/26/2019 at 1:23 PM, Mike J. said:

If I remember correctly, the engine will start if the speed is over around 42mph, so some protection if speeds are high and you are not using B mode.

Yesterday, I kept an eye on the EV light as well as monitoring the diagram on the screen.

Two long descents. One of 1.75miles and another or 2.6miles, the first I was coming down at speeds up to 60mph, and the second at the limit of 30mph.  The first, the EV was out but the car was showing a green regen power-flow without the pink of the engine running at all.  The second, the EV light was on all the way down.  No pink and never used B mode.

Therefore, for those descents, the gearbox wasn't being lubricated.  How would the gearbox feel if I'd been descending from Drumochter Summit the 20miles down to Pitlochry on the A9 at easily 60mph?

What about massively long descents in the Alps?

Surely, Toyota have sorted this?

Mick.

[TonyHSD]

Hi, why do you think the gearbox wasn’t lubricating, main lubrications comes from the spinning gear of the differential, it sends oil to the top of the gearbox and from there to the other gears and bearings. Oil pump is for extra lubrications and or extra cooling . There is a heat exchanger outside the box of some of the hybrid transmissions. Your car has only an oil that is lubricating and cooling the transmission, no coolant is circulating through. I think Yaris owners should change that gear oil more often than other hybrid owners, the guy from the videos said that the oil he drained prior to open the transmission for video and education was really dark. 

[Mick F]

So ............. the question still remains.

Why can't you tow a hybrid Toyota?

The gearbox is lubricated ........... and the MGs won't overheat as no power is generated in N with the power off.  The traction Battery is out of circuit.

I would like to read chapter and verse of technically why you can't tow one.  I understand Toyota say you shouldn't, but they don't say why.

Mick.

 

[FROSTYBALLS]

1 hour ago, Mick F said:

So ............. the question still remains.

Why can't you tow a hybrid Toyota?

The gearbox is lubricated ........... and the MGs won't overheat as no power is generated in N with the power off.  The traction battery is out of circuit.

I would like to read chapter and verse of technically why you can't tow one.  I understand Toyota say you shouldn't, but they don't say why.

Mick.

You need to pose the question directly to Toyota.

[Mike J.]

13 hours ago, TonyHSD said:

Hi, why do you think the gearbox wasn’t lubricating, main lubrications comes from the spinning gear of the differential

With the Rover SD1, oil goes down the middle of the mainshaft to lubricate items that won't get splash lubricated. My conjecture is that oil is also pumped down the middle of the two epicyclic gear sets (around the oil pump shaft) for the same reason. Check out holes in the shaft of the Power Split Device Planet Carrier.

[TonyHSD]

Correct, there are holes for that purpose. 👍

[Mick F]

20 hours ago, FROSTYBALLS said:

You need to pose the question directly to Toyota.

Ok, I can see that as an option.

To whom specifically do I send the query?

I may also ask why you can't tow WITH a Toyota Hybrid.

Mick.