Tesla Large Drive Unit Rebuild (For a Toyota RAV4 EV) Part 1

[@vesslewiththepesstle]

This video is a masterclass in the difference between knowledge gained from a classroom/books/online and knowledge gained from experience and that is the same for everything we do in life, great job.

[@bschena]

This guy is impressive. Well executed tear-down accompanied by legit knowledge about what he's working on.

[@dnomyarnostaw]

Terrific Video. Well narrated, well explained and terrific demonstration. Fascinating to watch.

[@echoewest2685]

Watching a guy that knows what he’s doing is very satisfying. Thanks for sharing!

[@ItsElectric-hf2dt]

Totally blown away! Such a complex process, and you make it look so easy at the same time! My deepest admiration for what you do, and hopefully you'll inspire many young adults, like yourself, to take up a trade like this! We will need them, lots of them! A++ on the video narrative as well!

[@0dbm]

Walking those two meshed gears out together was amazing

[@idanko731]

Really enjoyed this. I have never considered an EV but seeing that they are practically giving away older Tesla vehicles. I don't know much about them and am curious how difficult it would be to repair them. Seeing you take apart this drive motor was a very educational, I'm impressed with your knowledge and excellent instruction. I am really looking forward to more of your videos and will need to watch what you already have. Please continue, you have a lot of potential in making this a channel incredibly popular for the EV DIYer.

[@HANZELVANDERLAAY]

Holy smokes....a lot of parts...well done...

[@bombero34fr]

Very nice job! Clear explanation. Thank you.

[@KENNETHFRANCIS-nl1gd]

You should do an online teaching segment. You are great at it.

[@Nat_Ryder]

You are a very knowledgeable and skilled mechanic/technician. How did you get your skill and knowledge, I don't think there are many guys with your ability. To me you are one of the most important people in our modern world of new technology. Great job. I hope they are training and developing more skill people like you. Thank you for dedicating yourself to a most difficult and important job that has to be done every day.

[@lejoshmont2093]

In the back of my mind I always though I was a little rough when popping out cv axles. My pry bar is of equal or less length and I have only removed them on jack stands. Watching you do it, in what seems to be a more realistic instance, puts me a little more at ease.

[@MrBulfur426]

Smashing works, I learned a lot, as an old tech engineer, rebuilding induction motors, I love your work.

[@Poitda31]

Love your work and the way you explain the details. Master Class!

[@armandvandenbroeck9095]

Well done! Good video, looking forward to part 2...

[@sudiptakiran]

It shows when someone knows his job thoroughly!!

[@davros517]

Excellent presentation and very instructive , thanks

[@whistlingdiesel]

Hey, you know Robert from Aging Wheels stalls with his Tesla powered Ford Escape project. Your knowledge could speed up the whole thing and a collaboration would be beneficial for you both. Just saying. Great job on the RAV4!

[@dorhocyn3]

Yeah, he really could use some help and he seems like a nice guy, now that he got the bus out of his shop he’s got a Lotta room to.

[@ferrywobma1836]

Great video. You are extremely suitable as an instructor. First calmly tell us what you are going to do and what we as viewers can expect and then implement it. I'm looking forward to part two. Greetings from the Netherlands.

[@idus]

Alex saved me at a charging station when o tore apart my tesla at a charging stall. Isolation issues of course. Thank you sir! Tried dropping by the vista location and I was told you opened a new location. I’ll miss taking you away from work with tech talk.

[@Nicholas-f5]

Absolutely amazing, in the field?

[@idus]

@@Nicholas-f5yes on the spot. Took the whole frunk apart right at the charging stall. Then comes a brilliant gent and pointed me right to the problem.

[@philbro1829]

Big thanks for your deep dive into this bit of VEHICULAR WONDERMENT... it's all news to me and I'm very grateful for the presentation !!! Thanks again 😅

[@aussietaipan8700]

My 2015 model S 85 is in great shape with only 40,000 km on the clock but I've heard they do have issues with the large rear motor. This video and the next gives me the confidents to repair the motor myself in the future, very detailed and concise. Thanks so much for presenting these video's.

[@AlexEVRepair]

Your best bet is to pre-emptively do a rotor cooling delete to avoid these issues in the forst place!

[@Dyt34]

Thank-you Ray Rain man on the electrical side of cars lol.

[@SuperUbuntudude]

I just stumbled across your site and I subscribe your very clear and decisive. I'm gonna enjoy your channel. Thanks for your hard work.

[@abqcleve]

My goodness! What a fabulous video of work I've never seen done before. I have to be honest: after watching this, it may be a long while before I get up the nerve to buy an EV! What a job! Thank you!

[@usa-ev]

Thanks for sharing your expertise! Very cool!

[@brunolagace1135]

Nice job. Explanation was really good!

[@b67fstb]

at 49:50 I would use some wooden blocks under the prybars to save the flange housing. Very good job btw !

[@paullarouche4648]

This video is so well done I couldn't stop watching even though I do not own an EV. Alex seems so young yet he is clearly a master at what he does and explains everything so clearly. Great post production as well. Can't wait for part 2.

[@AlexEVRepair]

It's already out! kzbin.info/www/bejne/fIGrd6J9rpWNers

[@javig5045]

Mechanic have always amazed me, how they remember where all those parts go, just incredible, excellent tutorial and very educational, thank's....Javi G.

[@kwinterburn]

Excellent video , on the DC old drives I used to do , we made a T Bar to turn the gear train , it was a square tube a foot long with two long bolts to turn the gear and a locating pin for the turning centre , you just dropped it in and it gave loads of leverage without damaging anything with pipe wrenches

[@davep800]

You've found your niche in automotive (or anything else) repair. Be good in your niche, and people will find you and beat a path to your door for years to come. I'm a 70+ year old ASE Master in ICE stuff, but know little about BEVs. I learned some stuff here. When discussing used EVs, the concern is always with "remaining battery life". I suspected there may be more pitfalls than "batteries", and I was right. Like the coolant leak problem in the early drive units you show here. I hope to see you address other "issues" with the EVs in future videos. Good luck to you with your vocation, and your youtube channel. You're off to a great start.

[@internet-of-things]

Great explanation! I see is simple enough to do myself. Best part is that these fine enviromentally friendly cars can keep going for years more thanks to your help here Alex!

[@freddie825]

Finally I found a vlog, your vlog to understand better EV's. I really wanted to learn this new technology, (more familiar with ICE). Thus, I have SUBSCRIBED and will follow you....keep it up with the excellent vlogs.....

[@williamclark6466]

Thank you for sharing this in-depth educational repair video.

[@privateuser-xp4nz]

You should try a wobble socket for those hard to get bolts

[@robeigner4390]

That's a crazy place for the disconnect, something that's very important to have easy access in case of fires and other issues.

[@martialme84]

This is an educational video and you have a very good way of explaining things. Thanks for making this for us!

[@LawpickingLocksmith]

This makes buying an old Tesla a major risk in Australia. Finding a technician here that can do this is like finding a needle in a haystack.

[@6Diego1Diego9]

or like finding a billy in the outback

[@ha1010rd]

You can find them but when they tell you the cost of repair you probably just want to buy a new or used car

[@moestrei]

Coonabarabran/NSW/Australia here, I repaired a BMS board (AU$80) inside the battery of my Model S and also changed the rotor seal (AU$28) of my LDU. My vehicle is 10 years old with over 400.000km on the dial. All service doc and software is readily available. Best and by far cheapest to run car I ever had. There we have it, your major risk.

[@LawpickingLocksmith]

@@moestrei Great to know! QLD is the dumb state. Here you get arrested for repairing small electronics for $2 per hour as being against the old ruthless regime that wants socialism over all. Mate of mine had his mod S crashed heaps of times because nobody knows how to drive here.

[@mark95b77]

Just wanted to say thank you for a very well done video! Side note: please place the forks of your lift flat on the floor, if you get distracted and hook your foot/ instep your in for a world of hurt. Thanks again

[@Nicholas-f5]

You're right

[@motorv8N]

Fantastic video - clearly presented and explained. Subbed!

[@michaelreeves8164]

Great explanation and work on this motor. You are an excellent teacher and mechanic. Part 2 soon please.

[@AlexEVRepair]

It's already out! kzbin.info/www/bejne/fIGrd6J9rpWNers

[@diyEVguy]

Very well explained. Excellent video to convince 99% of RAV4 EV owners to NOT fix it themselves haha

[@Nick-wr7vv]

no kidding when he started taking electronic boards out with little tiny screws. nope. hahaha. and the dealer would of said. would you like to buy a new car instead.

[@charlougas]

Extremely Informative!!!!! well done!!!!

[@walter2990]

At 51:00, I'd suggest that you place some soft copper stripes on the housing that you're prying against to remove the smaller gear. Otherwise, I've been enjoying the rest of the video! You're a VERY gifted mechanic and I'm very impressed with your knowledge and professionalism with this issue! The bigger issue is WHY they haven't addressed the issue of a "known" coolant leak issue on these cars!

[@Nicholas-f5]

There are battery class actions

[@christianadams4673]

Terrific video, Alex! Thank you!

[@chriswilson7493]

Super clear camera work, explanation and audio. Thanks. Not as much of a nightmare as I was expecting, but probably a unit from a damp and salty environment, or a more elderly one would be a different matter ;) You're an excellent teacher if you don't mind me saying so, thanks again for sharing your knowledge and experience! Will watch with interest how you clean the rotor and stator and reassemble the thing :) I wonder what that vehicle weighs? Plenty I'd imagine...

[@AlexEVRepair]

Thanks for the compliments! The RAV4 EV weighs in at just over 4000lbs (about 350lbs more than a V6 AWD 3rd gen RAV4).

[@jansmit4628]

Nice and good explanation of how to do this repair which won't be easy outside a garage environment. To rotate the primary rotor gear, you should create a kind of wrench which falls in square holes in stead of using the waterpomp pliers which is notary to murder all objects it is clamped on. If you do these repairs more often you could really benefit from having such a tool.

[@michaelhawthorne8696]

Nice job....enjoyed seeing and hearing your knowledge of this unit... You clearly know this motor and its foibles.... Your specially made motor holder is well designed too.....at first glance I thought you were trying to balance a wheel...🙄

[@PaulCTownsend]

Great job. Automatic transmission technicians are quite capable of doing this job.

[@johncostigan6160]

Absolutely fascinating. I'm stunned at the level of, and the sheer number of different skill-sets you require to repair these automobiles. Who engineered the part of turning the main bearings to access bolt heads? Elon? I spent a year assembling AMC Gremlins. Who am I to complain?

[@johnkeelan]

What an amazing tech!!

[@floridasaltlife]

Make you up a Vise Grip Slide Hammer for that cast aluminum cover and there is no damage on that smooth sealing surface. Just remove the vise grip bolt and add an all thread rod and a small sliding steel weight and a double nut at the end to bang against. Old wrench here !!!

[@rawl91]

Hey Alex, Great content, I hope you work on a Chevy Bolt in the near future future, keep up the good work 👍

[@williamclark6466]

I was surprised to see you using a steel-face hammer directly on housing surfaces. I suggest using a soft-face deadblow hammer instead.

[@philoso377]

Nice video and presentation. Learned about coolant intrusion. I wonder if there is anti rust coolant on this part?

[@michaelcoghlan9124]

Thank you very much indeed for this video. It has been very useful. ❤. Good luck. M

[@Kenshin_Tran]

Whoa i was expecting a rebuild but not so in depth as you are. Great stuff! What does a job like this generally cost? This looks like a butt load of work

[@robeigner4390]

Compared to an ICE engine the Tesla motor is relatively easy to remove without many parts to disconnect. There are several things that need to be removed to get the motor out but nothing like removing fuel injection, alternator wires, spark plug wires, several belts along with worrying about gas lines full of fuel.

[@buzzbierbaum4026]

Great Video I just found your channel Amazing amount of details & video !! Working At Benz Dealer there just so much on tear down, we don’t get into due to warranty. It’s great to see hands-on inner workings and stuff we don’t get to take part!

[@AlexEVRepair]

Stay tuned for my upcoming video on a 2019 Smart EQ (that Mercedes canceled the battery warranty on), that's going to be an interesting one!

[@buzzbierbaum4026]

@@AlexEVRepairnice look forward to it

[@buzzbierbaum4026]

@@AlexEVRepair I definitely am will be interesting to see the inside of the Frenchie HV Battery

[@andyc8836]

Dude your like a drive scientist

[@LordCakeskull]

You could do with a giant C-spanner like you use to adjust sports suspension for turning the rotor by that parking pawl rotor, be a lot easier than the water pump pliers. Should be pretty easy to make on a laser or plasma cutter too.

[@ljprep6250]

Well done, Alex. Did you used to have a shop in Vista, CA a couple years ago? I saw a video and think you were in it.

[@AlexEVRepair]

I used to work there (and am still "partnered" with them). Just moved up here to Portland and opened this shop about 6 months ago.

[@williamclark6466]

Some more specialty tools (such as a spanner for rotating the parking cog) could help.

[@noelelnolo9642]

Alex, great video and explanation. Never knew Toyota had a Rav4 with a Tesla motor. Would like to know how much is all this work u r doing.

[@appomattoxross6751]

39:30 Wobble bit socket time.

[@johnwhitehurst474]

On Channel locks weld a stud on both sides so it becomes a tool to fit the notches on your main Gear, I think you said. Never saw one before but am ret Transmission man also. sometime one makes their own special tools. If there is not one patent it.

[@cristerhelin8532]

True professional!

[@doglegjake6788]

Excellent video

[@wholeheartedglobal316]

A masterclass.

[@JamesMiller-vi7ib]

Excellent video I just wonder what the parts and labor cost. Whenever you have new technology, you have new problems!!Cooling water leaking into the electric motor, what a hassle and a headache and expensive

[@Soapy555]

Good stuff 👍

[@Gersberms]

Amazing work. I would almost think that the RAV4 EV could have been the ideal car: a car built with Toyota experience, but with the electronics from what I consider the re-inventor of the electric drive train. Sadly Tesla once again shows they don't have the experience it takes (yet).

[@AlexEVRepair]

Well, they certainly didn't have the experience when these cars were built (over 10 years ago now). The LDU was Tesla's "first try" at building their own motor from scratch, and it definitely has issues... I've heard that the guy who designed it was an industrial motor engineer, and designed it like one would an industrial motor, rather than something that operates in the comparatively harsh environment of the automotive world. Suffice it to say he's "not around" at Tesla anymore. The 2nd gen and up Tesla drive units on the other hand tend to be pretty bulletproof in comparison. The first 2nd gen drive units (referred to as the Small Drive Unit) first started going into the Model S in late 2014, and share basically nothing in common with the LDU, apart from the fact that they use induction motors. Nowadays, Tesla is on their 4th generation drive unit, which uses a permanent magnet motor and "hairpin" design (cheap, robust, and efficient).

[@Gersberms]

@@AlexEVRepair I see. Munro always said they make a lot of changes. I've seen videos on the designs on Munro Live's channel but didn't get a real sense of the timeline. Doesn't the model S Plaid use a combination of permanent magnet and traditional rotor design?

[@AlexEVRepair]

Yes, saying that "Gen 4" (or even Gen 3) motors are permanent magnet is a bit generalizing on my part... Really they are a mix of both depending on placement. Any Tesla that has gen 3 or newer motors uses one permanent magnet motor, and if a Dual (or Tri) Motor version, induction motor(s) on the opposite axle. The reason for this is that induction motors can be put to "sleep" and remain connected to the wheels, while permanent magnet motors either have to be disconnected from the wheels, or always have some power flowing though them while in motion. Placement of permanent magnet vs. induction depends on which model/variant. Model S/X newer than 2019 (Raven or Palladium) use a front permanent magnet motor, and rear induction motor(s) (older models use ONLY induction motors front and rear). Model 3/Y are the opposite way around, rear permanent magnet, and induction front (on dual motor models of course). Cybertruck is a bit odd because it goes both ways, the regular dual motor version uses permanent magnet rear and induction front, but the "Beast" tri-motor used induction rears and permanent magnet front. Other manufacturers all have their own approaches when it comes to using multiple motors on their EVs. Some utilize a mix of motors like Tesla does, while others use clutch packs to disconnect the wheels from the "non-primary" motor when it's not needed. Tesla actually does this on the Semi, which is their only vehicle to utilize axle disconnects.

[@allterrainrandy2587]

​@AlexEVRepair how does the plaid do it?

[@audelioespinoza1934]

Bukele el Presidente de El Salvador dando in gran discurso y catedra para los Presidentes de Latinoamercs

[@megamanguy]

36:28 "Wherever I can get the best purchase" Fancy wording there.

[@christophersherratt7299]

This may sound silly but why run the coolant through the motor why not run a conditioning pads around the out side or use a direct air cooling from outside funnelled around the stator??? I think that would work ????

[@solonutiket564]

It seems like it would be an advantage to have the design engineers repair these before designing new ones.

[@benkanobe7500]

Alex, great job explaining and showing the process. I read the notes under "more" and have an important question. We have not taken the out of warranty car to Tesla yet. I have two identical 2015 Tesla Model S P85 Ds. From the rear, one of them makes a very high pitched spinning-up-turbo-sound (whine) from about 1 MPH to 20 MPH. It just started and can only be heard with the radio off and the AC with fan below "7". There is zero change in performance. The other "S" makes the same sound from 1-3MPH and always has. Is this the beginning of the problem you show here? Thank you for and recommendation(s). PS LOVE that engine stand! Brilliant.

[@AlexEVRepair]

A "milling" sound can definitely be a potential sign of coolant intrusion, but could also be caused by wear of the rotor or primary drive gear bearings, which is a relatively common phenomenon. Best thing to do would be to pull the rotor encoder sensors on both of them to check for any signs of coolant intrusion and continue to check them *at least* once or twice a year (or better yet, pre-emptively perform a rotor coolant delete before coolant intrusion begins to set in).

[@benkanobe7500]

@@AlexEVRepair Thank you Alex! Both cars have less than 40K miles and the one making noise (mine has done it since new and it has never become louder or longer) is my wife's and she drives it on "Chill" 100% of the time and conservatively. If it is wear, that would be strange. Your counter part in San Marcos/Vista area by me has a very, very bad reputation "Tony" and so I will need to perform the inspections myself. Thank you for the help. I wish you were closer! I would just take it to you and say "fix it". Thanks again for such a great KZbin and for the advice on doing the inspections. I will do that. Does Tesla put in the the nonconductive bearings (like the newer S's have) or do they just put in the exact same thing that is in the car now?

[@AlexEVRepair]

The wear issues aren't really associated with driving style, more just part of how the motor operates. With the steel bearings, they end up acting as a "discharge path" for energy buildup in the rotor to dissipate to the case. This essentially causes "arcing" within the bearings, and causes irregularities in the bearing races, leading to noise. It's not a "critical" issue, as long as it doesn't continue to get noticeably worse. Both of your cars should already have non-conductive rotor bearings (which started being implemented sometime in 2014), but the primary drive gear bearings are still regular steel bearings on all factory LDUs. On my rebuilds these days, I typically install the non-conductive bearings on the primary drive as well to avoid those noise issues in the future. They're quite a bit more expensive than regular steel bearings, but well worth doing while the motor is apart.

[@benkanobe7500]

@@AlexEVRepairGot it! Thank you. I take it Tesla will not "rebuild" and add the non-conductives and only R&R with new or Tesla rebuilt? I wonder what it would cost to have my wife's car sent to you and then I could just road trip it back (?) I don't think other than Tesla I have any options (any more) in San Diego area. I really appreciate your honest responses and as old retired Wrench, it was great to see all your good and highly skilled work.

[@AlexEVRepair]

No, Tesla does not do rebuilds at the service center level (instead they get sent away to be "remanufactured" and then re-sold again). They also of course won't retrofit your existing drive units with rotor cooling delete either. The only thing they can/will do is put in a new or remanufactured drive unit, which should be the latest "U" revision (released towards the end of last year), which is equipped with a factory rotor coolant delete manifold. At last check, the cost to have that done at the service center was somewhere in the $7-8k neighborhood (~$6k for the drive unit + R&I). As far as I know, the bearing setup in the current motors is the same as it has been since ~mid-2014, which is non-conductive hybrid ceramic bearings on the rotor, and conductive steel bearings throughout the gearbox. Though I haven't had a Rev-U motor apart to confirm the bearing setup is the same, I've certainly had plenty of newer (2020+) motors apart that still retained that same setup. As far as cost to transport, I could put you in touch with a transport broker I've worked with a bunch in the past if you'd like. I'd imagine the cost one way to be somewhere between $1,000-1,500 from San Diego. Feel free to give me a call or shoot me an email if that's something that you want to look into.

[@irgtk]

I was wondering if a strap wrench would be a better choice instead of the water pump pliers. Is there any chance creating burrs with pliers?

[@andrevanrooyen7789]

Excellent !

[@FrankBrown-c5l]

Good grief, I've seen it all now. A car mechanic who knows what he's talking about. Usually, it's a case of, "This, that and the other need replacing at a cost that will bankrupt you".

[@scapp9507]

Bolt sizes are determined by their diameter, not by the size of socket that fits the head. You don't use a 1/2" socket on a 1/2" bolt and you don't use a 17mm socket on a 17?mm bolt. A 10mm bolt usually requires a 17mm socket and an 8mm bolt typically has a 13mm 'across the flats' head.

[@johnchildress6717]

You are a very skilled tech.highly.I am glad I Watched and will not own an ev.Thankyou.

[@KO-pk7df]

Great video, I love this generation of the Rav4 Mine is the 2010 Limited. But I have read about these electric versions that were sold in special programs. But I did spot what I believe is a mid to late 60s Kawasaki in your shop. Is that a project your working on for a battery/electric conversion?

[@AlexEVRepair]

The electric ones were only sold in California to meet the state's Zero Emissions Vehicle credits, essentially as a stopgap until Toyota could build the hydrogen fuel cell Mirai (which has been a complete flop). A total of 2538 RAV4 EVs were built from 2012-2014, as well as around 70 Scion iQ EVs (their target was to build 2600 EVs for that 3 year period). Since then, the RAV4 EVs have been exported not only all over the place. Last I knew, there were several hundred in Norway, as well as a bunch more in Ukraine, Jordan, Costa Rica, U.S. Virgin Islands, Alaska and Hawaii, not to mention the vast number of them across the rest of the U.S. and Canada. It's hard to say how many stayed in California vs. going elsewhere, but I'd estimate it's about 50/50 these days. And yes, that is a 1967 Kawasaki A1-SS, which I first converted to electric during my freshman year in college nearly 10 years ago. In fact, if you look back through the old videos on this channel, you'll see a few short videos I made about it. It hasn't been on the road in several years now though, and I'm currently in the process of completely rebuilding it with a totally different powertrain, so stay tuned for some videos on that!

[@fredpinczuk7352]

@@AlexEVRepair Nice work and great write up. It was a little more than a stop gap, originally Toyota had an agreement with GM to supply all powertrain (motor, BMS and Battery) for their RV4 California EV program, since GM had bought a Japanese supplier right under there nose and right in their own country. Only problem was, 3 years in. GM decided to sell the patents and trademarks to a oil company who turned around and buried them. All the while filling and winning a lawsuit against Toyota and imposing a 15 year gag order. Toyota had no choice but to pivot and use drivetrains from a little unknow company in San Fran called Tesla (Way before Eloon and the Model S ever came out). If it wasn't for GM greed and shortsighted. Tesla would never have become what it is today.

[@Nicholas-f5]

​@@fredpinczuk7352insightful: Chevron was the culprit, wasn't it on the large format lithium patents being held back a decade?

[@fredpinczuk7352]

@@Nicholas-f5 Yes, correct.

[@ele4853]

Sir! After all this work you are going to keep the statue with 30 Mega Ohms of insulation resistance? I would replace if less than 100.

[@phiiz3r]

You can tell this has taken many of these apart before .

[@raystevens687]

Would a 2 prog gear puller work on that small gear.

[@emilianotaala1734]

This electric vehicle is easy to repair when you have the knowledge of basic electronics and repairing electric motors.

[@rossr6616]

So, did Tesla cheap out on the seals? or was there a vibration/heat problem? or?

[@Karlkn]

As a new subscriber, I purchased a, new to me, 2022 Model S LR, anything I should be worried about??

[@raystevens687]

Did you make that motor stand or did you buy a factory built stand. I was just curious.

[@raystevens687]

I'm surprised that Tesla didn't make that part from stainless steel.

[@mortegasr]

Can owners be proactive and "drill a small hole" in it? Draining is cheaper to diagnose if it occurs.

[@AlexEVRepair]

For one, a hole would have to be drilled in the correct location as to not cause any damage of course. A drain hole can help evacuate coolant that leaks, but doesn't fix the root cause of the issue, which is the rotor coolant seal. It could buy you some time, but is ultimately a "bandaid" fix. As I mentioned towards the beginning of the video, diagnosing the issue is as easy as removing the rotor encoder sensor (aka "speed sensor") and visually inspecting it for signs of coolant. The key is catching the issue BEFORE catastrophic damage occurs, which is why it should be inspected regularly, I would say AT LEAST twice a year; and even that is no guarantee that you'll find the issue before it causes damage... This customer got lucky, in that the coolant didn't damage the inverter or cause a major loss of isolation in the stator, which would have resulted in a much more expensive repair. The permanent fix for this issue is to bypass the rotor cooling, and eliminate the seal that fails, which I will be going into more detail with in part 2. Tesla has done this with their latest revision of the LDU (Rev U), but unfortunately they have not made the manifold available as a standalone part. Luckily, there are now several aftermarket rotor coolant delete options as well, including the QC Charge manifold that I played a major part in the design of. Installing a rotor coolant delete can of course be done preventatively before any leakage occurs, and avoids having to perform a full rebuild in the future.

[@mortegasr]

@@AlexEVRepair Only intended to provide real time indication by finding "piddle on the garage floor. Fix necessitates as you say.

[@bubferner2146]

If a 2012 MS has a low iso condition in the RDU, would it likely be repairable like this or is there a high likelyhood the inverter been damaged?

[@AlexEVRepair]

If you have low isolation, it's likely that the stator has suffered from too much coolant intrusion... In some cases they can be recovered if they're not too far gone, but in my experience, that often isn't viable. Whether or not the inverter is fine is impossible to say without performing a teardown to see if it was exposed to coolant. Typically if the only codes present are for loss of isolation though, the inverter is *probably* OK.

[@christophersherratt7299]

And on the speed sensor why don't they use a rubber bung as you tighten the bolt it compressors the bung forming a very tight seal that would not leak ????

[@AlexEVRepair]

The speed sensor isn't the source of the leak, The actual leakage point is the rotor coolant seal, which just happens to sit directly adjacent to the speed sensor.

[@timmeah1]

Great video Alex! Random question, but do you have ASD? I do, and I thought I could see it in you. Whether you do or not, your attention to detail is wonderful and you have such a wonderful way of explaining the info to be very accessible and easy to understand.

[@daytonpyro]

1.55K subscribers, plus 1

[@rawl91]

How many miles on that motor?

[@markusdd5]

lol I was not aware they actually put the large drive unit in these.

[@AlexEVRepair]

Yep, and in the 2014-2017 Mercedes B Class ED/B250e as well!

[@markusdd5]

@@AlexEVRepair this one I knew about. And they were stupid enough to not want supercharger access so the car became useless

[@Nicholas-f5]

​@AlexEVRepair the small motors are used for DIY EVs

[@hollisinman6989]

talk while doing use voice over if needed, south main auto, chef john(do not talk then do). focus on this car only. if needed use the lead in on the bolt removal for side notes. speed up of bolt removal is very good. might want to show the removal bolt 1 and just the end of 2 and three see cutting edge engineering. Karen is very good at the finer points.