@muehlpower: I don't have time for this yet I can't let go :ugeek: : Very interesting design! It looks like the lip is CNC machined and definitely not formed using a mandrel. Some questions and remarks in random order (I may be dead wrong of course):

1) Does GFD have experience using this design ...

My earlier statement that my single lip Tesla seal was "worn out" was probably incorrect. Instead, it probably already had a smaller thickness from the start (in the reagion where it contacts the shaft) due strains induced by manufacturing and installation. I explain it in more detail on Youtube :

Here's my rotor shaft end measurement in millimeters (sorry British people and their colonies, no inches today). The resulting chamfer angle is ~9°, based on two measured diameters plus the shown 1.5mm chamfer length in axial direction. Of course maybe I made a measurement mistake. Could someone ...

If I summarize, I come up with a PTFE seal and a good shaft that only needs to be polished, or the use of a speedi sleeve with something for better heat transfer. The PTFE seal would then be the same. So I will ask GFD what the best material and design is. Shaft 55HRC, Ra 0.4µm, medium water/G48 ...

If you plan to use a Speedy Sleeve because the shaft surface is bad, then I would highly recommend using a thermally conductive epoxy to fill the microscopic gap between sleeve and shaft. Not doing that can (according to my heat transfer model) severely increase the seal temperature and cause early ...

Boxster EV wrote: ↑Mon Dec 05, 2022 3:08 pm Additionally, do you have a view on whether Nitrile rubber will be more durable than fluoro rubber?

Nitrile is worse than fluororubber. See also the graph on page 6 of this thread.

WimV wrote: ↑Tue Oct 04, 2022 10:46 am It looked like the white sleeve is embedded in the stator, so I don't expect water to leak in the sleeve.

Yes, the brown stator potting resin encapsulates the white sleeve in my LDU too.

@SuperV8: Thanks for that graph!

Increase of the shaft diameter is probably not a solution in this case. Here's why: Start with the requirement that the LDU must sustain a continuous maximum speed of for example 100 mph (161 km/h). This corresponds to 11479 RPM, given an assumed tire diameter of ...

Boxster EV wrote: ↑Wed Aug 31, 2022 6:35 pm @johan how are you getting on with the Toyota?

After some error message trouble (see here for a video log), I was able to put the car back together correctly. So far, the Chenming seals have run 80mi without leaks. I could not drive much yet, partially bc I was overseas .

@TastyGuac:
O-ring.PNG
The maximum inner diameter should be 24.25mm in order to fit snugly around the speed sensor ("circuit assembly switch").
Mine measured 23.85mm after taking it off the sensor.

The minimum outer diameter should (after assembly and straining) be 27.00mm in order to fit snugly ...

Speaking of seals, have any of you seen these? Seems like Tesla themselves have been trying these multi-lip seal designs. The bearings and new seals I bought on eBay came from Kiev, Ukraine where this shop seems to be too.


I logged into the official Tesla Parts Catalog and those seals are not ...

TastyGuac wrote: ↑Wed Jul 27, 2022 4:15 pm The rotor did NOT want to come out.

How did you get the rotor out? Did you open the gearbox, remove gear shafts, and hammered the spline end? Did you soak the rotor in rust remover of so?

Email from Electrified Garage: "Sorry we haven't gotten into rebuilding drive units they're typically too far gone by the time we see them."

That is the problem: Most Tesla drive unit owners are not aware that you have to periodically check the speed sensor for coolant leaks. QC Charge is pretty ...

One lip failure from the Chenming seal may be explained by looking here:
Speedy Sleeve.PNG
The left lip made contact with the cratered shaft surface, not with the sleeve. That explains failure of that lip. But what about the middle lip? That one should have functioned, right? Then why not? Maybe ...

Maybe the oil seal will go longer or check with a speedi sleeve?

The HMS5 V seal will most likely make contact with Boxter's sleeve, because there is at least ~3.5mm left to the edge of the sleeve (estimation based on pics above / DU CAD model shown below / SKF seal CAD, assuming the DU ...

@asavage: Thanks for contributing!

Ceimin is said to be a name brand owned by Chenming according to the person responding to questions in the chat here on AliExpress [edit:] and Chenming verified this in writing . I know that it is a common problem that "middle-men" act as if they are the ...

What were you all able to find on the coolant?
Any thoughts on this appreciated.


I use Zerex G48 too because my Toyota RAV4 EV Owner's Manual AND Toyota's garage manual prescribe it. The drive units are identical between RAV4 EV and Mercedes BED, except for the inverter electronics, so I expect ...

Vsevolod wrote: ↑Sun Jul 10, 2022 10:26 pm There are people who make a new surface with the help of spraying.

Yes: example of spray welding of tesla rotor on Youtube

Maybe we just have to live with a bit of a leak and install a drain and 12V pump it back to the coolant reservoir (drill small hole next to reluctor wheel etc etc).

Also check a good related thread on ENG-TIPS.com. From this thread (FWIW):

"Bear in mind that PTFE is a sintered product, inherently ...

Vsevolod wrote: ↑Sun Jul 10, 2022 8:08 pm Have you watched saint gobain? Judging by their catalogs, they may have worked or are working with Tesla.

I reached out by webform, email and phone, but no response so far.

Just to check this is the part:
https://simplybearings.co.uk/shop/product_info.php?products_id=308259&vat_inc=true&gclid=Cj0KCQjw8amWBhCYARIsADqZJoUbmTnS9R8kewNem1y80bWXyBKsGq2m9z0uk-19E7q7fagV-hfKEWIaAiCCEALw_wcB

The model number matches, but I could not find Simply Bearings in the SKF ...

This guy bought a replacement seal from HybridRevolt. I contacted both the youtuber and HR, but no reply yet.

I think that most of SKF's PTFE seals are custom made to order. The closest SKF off-the-shelf catalogue seal that matches the desired dimensions and is able to run at 12,420RPM is the rubber(!) seal model HMS5 V , but that one is "designed for oil or grease lubricated applications" ( source ). The ...

@Boxster EV: O no! Thanks for the update!

Guess what: SKF actually showcases "SLX"(?) PTFE seals with concentric cuts (as in my Tesla DU, see my previous msg) here on their website , repeated here:

SKF seal.PNG

So maybe SKF is the supplier after all. Or not, who knows. Also: "The majority of ...

@muehlpower: Thanks, it could indeed be a thread/helix/spiral to "drag" the fluid back to where it came from. I took some measurements (click to enlarge):

seal helix.png

So I think that the cuts are concentric , primarily for structural instead of hydrodynamic purposes. It would be nice if ...