DIY Tesla Drive Unit Repair

[howardc64]

C/P from evclinic:

Our new coolant system cant ever ever again let coolant inside stator.
Our new stator cant ever ever get low isolation or overheating problems
Our new stator should increase range and power, decrease heating of the system
Our complete LDU assembly should last at least 700000km

If this is true, then its really good news. I want a P100D model, but untill now the fear of replacing LDU every xy K miles was a deal braker...

Do you think its true what the evclinic is saying and that even the LDU can be "fixed" properly?

My understanding is EV Clinic use triple lip seal. Currently I only know 1 triple lip PTFE seal supply for this LDU from small Chinese company via Aliexpress. Many DIYer worry poor quality from aliexpress seal. But from every LDU rebuild I have seen, they ALL use this seal. I can easily confirm from their pictures, videos etc. Personally I think there is no magic about PTFE seal, just need to have the right hardness blend (and the mating shaft surface MUST be properly prepared) Other big seal vendors such as SKF, Saint-Gobain, Parker have custom seal divisions but they seem to only focus on high volume OEM business. I doubt any small quantities are provided. But maybe EU with higher right to repair culture have other triple lip seal sources for small quantity for shops such as EV Clinic. Anyway, if I had to guess, I think EV Clinic use Aliexpress seal.

Finally, will a triple lip seal with properly finished rotor shaft surface last 700km? Personally I feel that is too optimistic. Seal and/or shaft will wear as I noted in above thread post depending on hardness of PTFE blend material and shaft metal alloy blend hardness. But I do believe EV Clinic so far shows the best rebuild process I have seen. Their video actually show carefully prepare the rotor shaft surface via chrome plating.

Almost all the longest lasting LDU we have seen are all early made factory original new LDUs. I'm guessing they last because 1) pristine new rotor shaft surface 2) triple lip PTFE seal. All the Tesla remans are single lip seal and what appears to be unrefinished rotor shaft seal surface. So if EV Clinic do good job on shaft surface preparation, maybe 300-400km is possible? We have heard some original LDUs lasting over 150k miles. But also its not clear who is careful checking LDU for leaks. Leak doesn't mean LDU is dead immediately. It depends on how much leak rate and how far leak progress inside LDU. It is difficult to find people willing to climb under the car, remove belly aero pan, check speed sensor even 2x/year.

I think the history of Tesla LDUs is early cars had LDU changed out frequently due to other problems (drive load clunk, non ceramic bearings micro arc welding noise) so reman process started quickly and unfortunately it seems to be a fairly poor reman effort. Therefore many car's LDU suffer from this problem but some people luckily never changed from original early new LDU and seem to have no leak for long periods.

Of course Tesla is now installing LDUs without rotor cooling. But this just started so the public do not yet have longevity data. I did quick research on how rotor fails with high thermal ( link )

I know this thread and openinverter threads are long with many posts. LDU coolant leak seems to be a science project for everyone including Tesla. Tesla found no solutions in 10 years after talking to many seal manufacturers (I talked to many, they all said Tesla / tier 1 supplier contacted) Eventually, not cooling rotor with coolant is the current solution after so many costly remans.

 

[brainhouston]

C/P from evclinic:

Our new coolant system cant ever ever again let coolant inside stator.
Our new stator cant ever ever get low isolation or overheating problems
Our new stator should increase range and power, decrease heating of the system
Our complete LDU assembly should last at least 700000km

If this is true, then its really good news. I want a P100D model, but untill now the fear of replacing LDU every xy K miles was a deal braker...

Do you think its true what the evclinic is saying and that even the LDU can be "fixed" properly?

They sound like Elon's twin

Anyhow, none of this is necessary anymore since Tesla went to bypass the rotor coolant now on - U drive unit
Everyone else will catch up soon n do bypass too (can easily be done DIY style)

 

[LonelyMS]

How much is the new LDU from tesla?

 

[howardc64]

How much is the new LDU from tesla?

Probably locale specific so you should inquire SC near you in EU.

New (and reman) rev U LDU will no longer have leak problem since rotor cooling is deleted. Older rev new LDU may not last as long as early ones. I suspect once Tesla went to single lip seal for reman LDU, they may have just used the same seal for new also (I have seen on Rav4 EV, original new LDU + single lip seal, fairly early rev)

 

[brainhouston]

How much is the new LDU from tesla?

from ppl posting invoices here, its about $5k for base n $7k for Perf version.

 

[philip295]

How conductive is G48/water coolant ? I'm just wondering if the rotor shaft cooling had a secondary design purpose. I watched a Weber YouTube about a hyundai drive unit, which had carbon filaments touching the rotor shaft, to save bearing arcs. Could the rotor coolant have been designed for the same reason? Then with ceramic bearings, no need for it?

 

[mr_hyde]

My understanding is this is the reason they went to ceramic bearings - the very first motors had arcing problems. The G48 does conduct some but certainly not like a carbon brush. Your question is one of the many things that 'could go wrong' with a major design change. As more of these go into circulation, there will be more data and time will tell...

 

[ajbessinger]

FYI folks, QC Charge's first batch of production rotor cooling delete manifolds are in. These allow for a complete elimination of the rotor cooling seal that is the cause of so many failures on these drive units. Pricing starts at $599 for the manifold. For shops or people doing a lot of rebuilds, bulk discount pricing is available for 10+ units.

The manifold also has built in provisions to add oil cooling for the rotor for the folks that want it. The oil cooling hardware is not yet available to purchase, but can be added at a later date (or I suppose if you're really daring, you could try to DIY your own system).

If you're interested in ordering, you can order at this link, or call the shop at +1 (760) 798-0342

COOLANT DELETE Tesla Large Drive Unit

Don’t let a leaking rotor seal in your Tesla motor cause expensive damage! All of the cars with the Tesla “Large Drive Unit” (formerly the “570A” motor) have the fatal flaw of leaking coolant (cars listed below). This leaking coolant issue will short out the stator (field windings), seize and...

qccharge.com

 

[mr_hyde]

Alex, quick question on installing the oil option later: As discussed briefly in the Facebook group, the leaking seal will pretty quickly destroy itself when the car is driven 'dry'. If someone has a leak today and opts to install the coolant delete now, I presume adding the oil coolant later will require pulling the LDU and installing a new seal to hold back the ATF that would then be cooling the rotor. Do you have a timeline for when the coolant parts will be sourced and available as part of the kit and/or a guess at the additional costs?

Bonus question - Do you have test units out in the world running the temperature sensor and if so, what temperatures are you seeing? Bonus, bonus question, do you have deltas on those temperatures between input and output under various conditions?

 

[ajbessinger]

Alex, quick question on installing the oil option later: As discussed briefly in the Facebook group, the leaking seal will pretty quickly destroy itself when the car is driven 'dry'. If someone has a leak today and opts to install the coolant delete now, I presume adding the oil coolant later will require pulling the LDU and installing a new seal to hold back the ATF that would then be cooling the rotor. Do you have a timeline for when the coolant parts will be sourced and available as part of the kit and/or a guess at the additional costs?

Bonus question - Do you have test units out in the world running the temperature sensor and if so, what temperatures are you seeing? Bonus, bonus question, do you have deltas on those temperatures between input and output under various conditions?

Yes, retrofitting it with the oil cooling later would necessitate pulling the motor and removing the manifold so that the seal and tube could be installed.

I don't have an exact timeline for when the oil cooling parts will be available, but likely later in the spring. For the vast majority of applications, the oil cooling is gross overkill, but it's there if you want it... Keep in mind that even from the factory, the amount of cooling the rotor got was pretty minimal, with the bottleneck being a hole ~ 1/8" (~3-4mm) in diameter.

Hopefully we will have some data available at some point as to the amount of cooling that the oil system provides, but I don't have that as of right now. As far as measuring the temperature of the rotor itself, there's not really any feasible way to do that in a way that would give any useful insight as to what is going on inside.

 

[mr_hyde]

Thanks Alex. People who might want the extra cooling might be people towing an RV with a Model X or people who spend every weekend at the dragstrip or track with their DL? Safe to say people who occasionally squirt up the onramp or make a passenger giggle with a occasional launch are probably fine with the uncooled rotor?

 

[ajbessinger]

Thanks Alex. People who might want the extra cooling might be people towing an RV with a Model X or people who spend every weekend at the dragstrip or track with their DL? Safe to say people who occasionally squirt up the onramp or make a passenger giggle with a occasional launch are probably fine with the uncooled rotor?

Pretty much. Personally I wouldn't bother with it, unless for something like a LDU used in a high performance conversion or racing application, or maybe something where higher power is needed for extended periods of time. But the provisions are there for anyone who wants it.

 

[asavage]

Both with and without the oil cooling loop are great aftermarket options, and I hope these will make it to production (unlike Tony's battery health monitor for the RAV4 EV, and his Model 3 cells retrofit, "coming soon" projects, which never made it to fruition, though he posted them both as for-sure-gonna-happens).

You will want your web guru to fix a couple of typos over on the storefront: the GM spec lubricant is "Dexron", not "Dextron".

COOLANT DELETE Tesla Large Drive Unit :

I see two things while nearing the end of Jan2024:
1) The web page that describes this product continues to mis-label Dexron as "Dextron";

2) There is now a one-star review of the product (obviously, not of the product) from a frustrated potential customer who cannot obtain any communication from QCP. This was my experience years ago as well -- when we had a $21k transaction on the table with Tony, he would neither return emails nor voicemails -- which is one of four reasons I advise people to avoid Tony Williams' enterprises when a reasonable alternative exists.

I assume that the one-star review will shortly disappear.

I like the idea of QCP's replacement/upgrade coolant manifold a lot, and Alex has been more forthcoming with information than anybody else at QCP has for years, but I've read a lot more hype from QCP than reported results over the >decade I've followed them.

 

[ajbessinger]

I see two things while nearing the end of Jan2024:
1) The web page that describes this product continues to mis-label Dexron as "Dextron";

2) There is now a one-star review of the product (obviously, not of the product) from a frustrated potential customer who cannot obtain any communication from QCP. This was my experience years ago as well -- when we had a $21k transaction on the table with Tony, he would neither return emails nor voicemails -- which is one of four reasons I advise people to avoid Tony Williams' enterprises when a reasonable alternative exists.

I assume that the one-star review will shortly disappear.

View attachment 1011050

I like the idea of QCP's replacement/upgrade coolant manifold a lot, and Alex has been more forthcoming with information than anybody else at QCP has for years, but I've read a lot more hype from QCP than reported results over the >decade I've followed them.

I'm not going to defend Tony's lack of communication here (he's certainly not the easiest to get ahold of at times). I will say though, that for most of the month of December, the shop was shut down for moving/setting up at a new location, and of course nobody was there over the holidays. I myself am not present down in San Diego anymore, as I am working on opening a second QC Charge repair shop in the Portland area. I used to handle quite a few of the emails and phone calls, but being that I'm no longer present, I'm not involved in the day-to-day operations down there anymore.

I do believe the customer in question regarding the review has been addressed, and you are certainly not the first to take notice of it. The review will remain on the site for the foreseeable future (we do not remove reviews, regardless of the reason). The first batch of delete manifolds are indeed in stock and a number of them have been shipped out and/or installed already. Tony and one or two of the other guys from the shop (not sure if I will be going yet or not) are actually going to be installing a bunch of these in the SF bay area next Sunday on a bunch Toyota RAV4 EVs, and maybe a Mercedes B-Class or two? No Model S/X unfortunately since it's just going to be a one or two day thing, and they take too long to fit into the schedule (RAV4 and B-Class on the other hand can be installed without removing the motor, so it only takes about an hour or two for the whole process).

The manifolds are of course also available for local pickup/install at QC Charge, or to be shipped out for DIY or installation at another shop. At least they will be until stock runs out, which it sounds like may happen sooner than was initially expected. It will probably take about at least a month or so to have another larger batch made to meet the demand we're seeing.

 

[Hank42]

For temp sensor, I think easiest is to put hole in end plate and point IR right at the end of the rotor. Can read after stopping or more advanced install for live reading.

IR sensors are tricky when measuring temperatures of metals and must be compensated for - could be tricky with grime and corrosion vs new metal etc:

Infrared Emissivity Table

www.thermoworks.com

 

[Z3ds]

Hi everyone I just discovered that I have coolant on the speed sensor of my model s. After researching and reading this thread I came up with this procedure to make a very easy “coolant delete”. It just uses Jbweld to block off the passage way leading up to the rotor. And block the top port where the pipe connects. May be sandwich a block off plate between the pipe amd the manifold?
What do you all think, this should work right?

 

[howardc64]

Hi everyone I just discovered that I have coolant on the speed sensor of my model s. After researching and reading this thread I came up with this procedure to make a very easy “coolant delete”. It just uses Jbweld to block off the passage way leading up to the rotor. And block the top port where the pipe connects. May be sandwich a block off plate between the pipe amd the manifold?
What do you all think, this should work right?

Have had similar thoughts. I wonder if JB Weld will seal completely from minute leaks against the coolant media?

 

[Z3ds]

Have had similar thoughts. I wonder if JB Weld will seal completely from minute leaks against the coolant media?

I guess jbweld then rtv sealant on top of it? I think the cavity going up to the rotor is has a rough surface and jbweld might be just enough the psi of the coolant flowing can’t be that high.

 

[brainhouston]

Hi everyone I just discovered that I have coolant on the speed sensor of my model s. After researching and reading this thread I came up with this procedure to make a very easy “coolant delete”. It just uses Jbweld to block off the passage way leading up to the rotor. And block the top port where the pipe connects. May be sandwich a block off plate between the pipe amd the manifold?
What do you all think, this should work right?

keep in mind the top port flows coolant farther thru the metal pipe so if u block it, you'll need to splice another way for it at the entrance port...

edit: also i'm not sure about leaving dry seal up there, not sure what will happen if it overheats/melts/smokes etc...

 

[Z3ds]

keep in mind the top port flows coolant farther thru the metal pipe so if u block it, you'll need to splice another way for it at the entrance port...

edit: also i'm not sure about leaving dry seal up there, not sure what will happen if it overheats/melts/smokes etc...

You’re right I really dont like the idea of just blocking the port and not use the pipe. So I revised the plan. Instead of abandoning the pipe, a tee fitting will be used to supply coolant to it. An ac block off kit can be used to block the port on top.