P85D LDU failure leak past rotor coolant delete by QCC

[utahski500]

Wish I had noticed issues with large drive unit earlier, but now out of warranty issue. 2/15 P85D 70988 miles.
$8022 to replace rear drive due to “moisture past RDU cover”. I am guessing it is the coolant past rotor seal failure. My questions: can I ask for my drive unit from Tesla once they replace it? Has anyone done the coolant delete fix from QC charge ($599)? Did Tesla ever have recall or fix for said issue? I honestly can’t believe there hasn’t been a class action. Thanks for your replies.

 

[brainhouston]

Did you make just one hole? On this photo someone also drained the bottom. Also what you're thinking about making a drain hole under inverter? The trapped moisture there is a common failure point but I can't find anyone who tried making a drain there without taking out the motor.

yes one hole and its in coolant manifold not motor cover like u pictured
i don't need to worry about inverter cause mine didn't start leaking yet, sensor was dry

 

[denonbike]

yes one hole and its in coolant manifold not motor cover like u pictured
i don't need to worry about inverter cause mine didn't start leaking yet, sensor was dry

Makes sense. No concerns about small bits of metal from drilling getting inside?

 

[j.harris]

Did Tesla ever have recall or fix for said issue? I honestly can’t believe there hasn’t been a class action.

They now offer a "U" revision LDU that has the rotor cooling bypassed. It's what you'd get for $8k they're asking.

Don't hold your breath on a lawsuit. They warrantied the car for 8 years and have replaced failed units under warranty with reman LDUs that also leaked.

 

[brainhouston]

Makes sense. No concerns about small bits of metal from drilling getting inside?

not really
maybe few small bits still there but they should stay on the bottom of manifold

 

[howardc64]

So I have an idea.. maybe a bit crazy but hey, at this point why not try.. Let me know what you guys are thinking.
So, there are some videos on YT about making the drain holes on the rotor side of the housing. But seems like you have to take apart the motor first in order to do that. I also learned that QC charge offers “storm drain” on the inverter side to prevent the moisture from building up and damaging the electronics, also done by taking apart the motor. I watched some videos where it’s clear that coolant accumulates on the bottom of inverter housing and just evaporates onto electronics.
Here is an idea - why not carefully make a couple of holes in the bottom of the inverter housing without taking the motor out? Can stick two tubes there so no dust gets in. The effort to get that motor out is massive and can’t be done on your own for most of us. But to get access to the bottom of the motor housing is super easy.
The downside is that leaking coolant will still be impacting the bearings and the stator, which could lead to an eventual failure due to rust. But I think the inverter damage is the main reason of the LDU fails.

I got 2014 85 with 150k on the original LDU motor and the seal is definitely leaking (based on the condition of speed sensor). No noise or any issues while driving so far.

Here is some guidance for an attempt ( link ) Very tricky with lots of issues and existing collateral damage will remain and further damage is likely as leak will not just seek out the drain for exit and likely some will continue to tour around the LDU.