Tesla Large Drive Unit (LDU) Motor Teardown and maintenance

[blodg1]

Hello everyone, I joined so I could add the pictures of the new 1002633-00-U Base-Drive-Unit here for everyone. These were taken in an Orange County Tesla Service Center.

[howardc64]

Moodifying an existing manifold should be easy. The tube is difficult to press out, but shortening it up to the retaining ring should work. Then you only need a cover in place of the sealing ring that leaves enough space for the shaft and has a gap to the shortened tube. If the gap becomes too small, a hole can be drilled into the duct below the pipe. I could imagine that omitting the rotor cooling works for lightly loaded engines, but I don't want it for my sport unit! Plug.png

One more consideration for gap calculation is the 2x bevel washer on the outer bearing of the rotor. This will allow rotor shaft extend outwards some distance (I think @Johan guessed 0.5mm.) Don't know if the o-ring in the bearing bore will reduce the travel. Its not much resistance but the o-ring is not lubricated.

[howardc64]

Hello everyone, I joined so I could add the pictures of the new 1002633-00-U Base-Drive-Unit here for everyone. These were taken in an Orange County Tesla Service Center.

This seems to be a brand new LDU made in 2023. T23*** printed on the motor end plate shows it was first manufactured in 2023. And no R + number at the end means its wasn't a reman (R1 = 1st reman, R2 = 2nd reman etc). Can you confirm?

Quite interesting if Tesla is still making LDUs in 2023.

[howardc64]

QC Charge now selling coolant delete manifold for $600. Also have additional oil cooling loop kit. Note QCC said rotor will show heat marks with cooling delete. My rotor after flame sprayed shaft repair showed some rainbow color discoloration on the rotor surface from the heat. Probably sealer heat curing for the porous finish.

Spoke to a Roadster tinkerer. Its rotor isn’t cooled. Don’t know about the stator. Roadster motor is less power.

People that tried to track model S knows car slows down after a couple of laps due to heat. Presumable inverter sees the stator temp sensor too high?

https://teslamotorsclub.com/tmc/threads ... -7903410yb

https://qccharge.com/products/coolant-d ... fe30&_ss=r

[howardc64]

Roadster has a 185kw motor without liquid cooling in rotor or stator. Looks like just heat exchanger fins outside of casing with active air cooling.

Pic of motor in pg 2-3 of this link https://www.allaboutcircuits.com/news/t ... echnology/
Tesla info (search for string "cool") https://web.archive.org/web/20100704030 ... logy/motor

Model S base is 335kw and Sport is 475kw so quite a bit more than the Roadster for a heavier car. But also gets liquid cooling on stator windings.

Here is an EV motor thermal review paper. Probably best we can do without an induction motor engineer chiming in.

https://kar.kent.ac.uk/92656/2/Revised% ... %94ATE.pdf

Its a long read but some interesting bits are

- Section 5 Conclusions... pg 48 states low heat density motors are usually air cooled.
- pg 26 talks about using fins on external housing to aid heat transfer. pg 27 also talks a air flow dominating heat transfers inside the air cooled motors (usually fins attached to rotor shaft that act as fan blades)
- pg 48/49 talks about most heat is generated in the windings
- pg 49 Medium heat density motors deploy liquid cooling
- pg 49 For induction motor, rotor cooling consideration is strongly recommended.

Without knowing how to calculate heat density. Sounds like Roaster motor is low heat density and Model S is mid level. S motor is quite a bit heavier than Roadsters. Maybe 2x+ if just comparing stator+rotor. If the rotor liquid cooling is deleted, there are no robust air transfer mechanisms on the rotor's heat.

[Haapala]

Hello everyone, I joined so I could add the pictures of the new 1002633-00-U Base-Drive-Unit here for everyone. These were taken in an Orange County Tesla Service Center.

Hi! Great photos. Could you possibly be able to take the coolant connection from the motor? We would sure like to see how it looks inside. If the coolant really has been blocked from the rotor or not.

[ajbessinger]

We're building our own version of a "rotor coolant delete manifold". This one can be used either as a straight up coolant delete (like the Rev U drive unit), or oil cooling can be added on for the folks that want it. We expect to have production ready units in stock starting in January.
https://qccharge.com/collections/ev-par ... drive-unit

[peakay]

Is anyone collecting data on the coolant delete LDUs yet or too new? temps or longevity info?

[Jalihuse]

I would like to share some information about my car. It is a 2015 P85D model LDU. Currently, it has covered 59,000 km. Unfortunately, the seal has leaked three times already. Since there is no service center in my country, I could not get the engine replaced under warranty. Fortunately, the coolant did not enter the inverter, and only the stator was flooded. By drying it, I was able to restore its normal resistance. After the second leak, we installed drainage and a three-lip Ceimin CTLBDYW seal to prevent further leaks. After driving 7,000 km since replacing the seal, an error message appeared indicating a low level of coolant. My measurements showed that over 2 litres of coolant had leaked out through the drain. Currently, there are no resistance errors and the car is running smoothly. I am now considering installing a bypass to prevent any future leaks.

[asavage]

Is anyone collecting data on the coolant delete LDUs yet or too new? temps or longevity info?

Other than development parts, the only coolant delete manifolds in the wild are ones that Tesla has installed via reman units, so it's unlikely that we would have any information available to us (unless Alex/Tony/QCC elect to release such development information on their own manifold and testing, and I wouldn't hold my breath on that).

[howardc64]

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[howardc64]

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[Affe]

Hello.

Need some help whit my rebuild.

1. What side off rotor should beavel shim be? Coolant or gerbox side?

2. Coolant side rotor bearing feels like it has spun in that bore. Can i gule this whit loctight? Or do anyone know what play bearing should have in this bore?

[howardc64]

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[Affe]

diagram for another person that forgot

viewtopic.php?p=57800#p57800



Both of my rotor bearing has o-ring in the bore so no locktite was necessary for me. Have seen others without o-ring and they used locktite on at least the gearbox side rotor bearing. I don't know about the coolant manifold side.



I'd imagine locktite can make it hard to get it out again. Mine gearbox side rotor bearing was rusted to the bore due to coolant leak and took quite a bit of force to get it out. Have also heard of cases of this bearing got pulled off of the rotor and stuck in the bore during rotor extraction.

My worrys is about if my bearing bore is out off tolerance bearing ring can spin in that bore, it look like my old bearing have spun in that bore. Anyone had same issue ?

[howardc64]

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[SuperV8]

I read about this 1.2million mile model S the other day - which shockingly has had 13 replacement motors!
Seems even Tesla couldn't fix it! Would be interesting to know what kept failing on these - if it was the same coolant ingress problem?

https://insideevs.com/news/699413/highe ... 14-motors/

[howardc64]

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[howardc64]

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[canadasconvert]

I found coolant in the Encoder Wheel area as well and there was a slight score on the rotor shaft pipe. I drained the oil in the gearbox and didn't find any coolant in the oil as it was also still red & clear. The inverter housing is also clean and dry. For rotor removal, can you remove the motor rotor from the stator without splitting the gearbox? I was thinking of lifting the entire unit vertically with the motor on the bottom and gently "dropping" the rotor out of the assembly as you suggested. Any downside to trying this?

[howardc64]

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[Boxster EV]

A small update regarding my SKF seal and speedi sleeve.

I pulled the encoder whilst fault finding this issue. The wheel was still dry. A little residue on the encoder but that might have been from the silicon used to seat the seal.

Edit: forgot to mention that I think that's 17k miles on this set-up but I haven't done many miles over the past few months.

[muehlpower]

Does anyone know what happened to howardc64?

[jrbe]

Does anyone know what happened to howardc64?

Is it common for the forum to mark all of a users posts as deleted if they leave?

If not, I'd guess he started a rebuilding service for these and decided to take his info with him - but I have no idea for sure.

[P.S.Mangelsdorf]

Is it common for the forum to mark all of a users posts as deleted if they leave?

I don't believe so - there are certainly some long inactive accounts where their posts are still up, but I don't know what happens if you delete your account - actually I'm not sure how one would delete their account and all posts.