All work you do on your car is at your own risk.
❗ First, read the EV High Voltage Safety section below. ❗
EV high voltage circuits are deadly, so familiarize yourself with safety before starting. Generally, the most important step is to disconnect the battery pack from outputing high voltage to the rest of the car. All EVs have easily accessible method for this. It is designed for emergency services personnel in case of accidents involving EVs. Recommended literature:
Hybrid/Electric training - by DiagnoseDan @ youtube
Hybrid and Electric Vehicle Personal Protective Equipment (PPE) and Tools - by Weber Auto @ youtube
Effect of 7620V and a single pinhole in a rubber glove @ youtube (illustrates relevance of glove pressure/leak check; I could not find a similar video for EV DC voltages)
Loss of Isolation Diagnostics - by Weber Auto @ Youtube
Insulation Testing on Hybrid Vehicles - by Garage Gurus @ youtube
The final report from the famous "Battelle Study" ordered by NTSHA (especially check the figures in chapter 5)
Research on Electric Shock Prevention and First Aid for Electric Vehicles - paper @ Researchgate
A LDU rebuild job is an advanced DIY skill level. Much online rebuild info is from peope with access to good machine shop level equipment. It is possible for mid level DIYer who has done things like change transmission valve body, removed CAMs etc. But likely well beyond light DIYers. LDU rebuild is of similar complexity as say a clutch or automatic transmission torque inverter replacement job. Some additional nuances are:
Weight: This job requires equipment to handle the very heavy LDU (lower from car, lifting onto work table) and manipulating fairly heavy components.
Coolant seal: Installation require more precision/care than typical oil seals. But very doable once learned the simple techniques.
Bearings: Requires the corresponding knowledge and tools. It could require to play with bearings and shop press under time-constrained procedures like installing frozen bearings for tight clearance, press in coolant seals that has just been stretched and with applied sealant) Made mistakes in both. First times and time-constrained procedures are not a good combination.
EV builders making a custom car with this LDU are likely to experience highly corroded shaft surface for mating the coolant seal. The shaft likely contains rusted pits after cleaning which requires metal surface repair. The shaft is probably not stainless steel (see Q&A) and corrosion is likely if the LDU has been sitting idle for long periods because. LDU has likely been idle for quite some time, for example in a wrecked car sitting in salvage lots for long periods, and/or the LDU pulled and stored for long periods. Coolant will likely leak out if it hasn't already, air and oxygen enters the cooling system and rust the shaft exactly where coolant seal will mate to the shaft. The shaft surface has to be recovered to prestine condition for proper sealing. The best thing to do for long term LDU storage is to probably remove the coolant manifold If it wasn't just fully rebuilt with all coolant vacated from the system. It is maybe also not good to have seal sitting idle on coolant shaft for very long periods (months to years) because seal failure seems not only develop with mileage but also with just time.
In most cases, cars with failed/failing LDU will have no choice but to go to a Service Center (SC) as other rebuild options require shipping cost and time delays. Tesla's LDU replacements cost is rumored to vary wildly. Actual quotes of $4800 and ~$750 install (depending on regional hourly rates) exist for MS85 (source) and P85 (source source). But have also heard of verbal quotes for $6k + $5k install (probably can't be right). QC Charge has noted prices seems to vary wildly since Tesla replacement is their competition. A possible reason for the wildly varying prices could be Tesla's own price fluctuation or their app based service communication solution. The app's chat communications have multi hour delays on each text and seemingly attended by not very automotive knowledgeable people. Along with frequent mistakes and probably a changing corporate price sheet for diagnostic fee. Was quoted $450 diag fee just to look at a wet speed sensor out of warranty in which a picture was provided in advance and mid aero shield already removed. But all this falls on deaf ears with whoever is on the other side of the chat line. Anyway, the app communication inaccuracies and frustration level can be a huge deterrent to those seeking cost effective solutions such as a DIYer. So it's a scenario that produces much hearsay and strong negative feedback. Tesla's replacement units does not include any collateral damage mitigation modifications and use the same old failure prone seal with high collateral damage. However, it can be done at your local SC and comes with 4 year 50k mile warranty.
There are very few independent rebuilders in US so statistically will be far away from the customer. Generally, even independents such as 057 (NC USA) and Gruber Motors (AZ USA) send LDU rebuilds to unknown third parties. It is expected that the rebuild business ramps up significantly as 2015 Model Ss will start coming off 8 year unlimited mileage drive train warranty. So the "next" LDU issue after warranty will be on customer's dime.
See also: TMC Repair Shop Directory
Near the epicenter of Tesla development and manufacturing, i.e. Northern California, Johan was referred to independent shops that were the best bet (mid 2022). None of these shops do LDU rebuilds: LusciousGarage | CarStar | A1 Body Shop | East bay Collision center | Dynamic Autoworks | EV4UNow | MakeMineElectric. The following shops are our only hope:
Located in Ocala, FL and Amesbury, NA: https://www.electrifiedgarage.com
Recently another rebuilder was added: EVsRepublic.com/services/model-s/drive-unit
A well known LDU rebuilder is QC Charge (QCC) in Southern California. QCC does high volume of LDU rebuilds and have added a fair amount of modifications to reduce collateral damage (bearing damage and fry the inverter electronics) with this LDU design where the coolant leak is basically unavoidable over time.
A QCC rebuild includes: (source: TMC)
Replace rotor bearings with upgraded hybrid ceramic bearings,
Replace primary drive gear bearings,
Replace rotor coolant seal with an upgraded triple lip PTFE seal,
Inspect all parts of the drive unit for excess wear (splines, gears, etc.),
drain kit,
1Y warranty (for QCC's longevity estimation, see the Longevity Page). TODO
Cost in 2022 was about $2800 if you ship the LDU to/from their shop. And ~$4500 if you drop off the car there. Need to add the shipping charges to both cases. In Johan's case (mid 2022) it was $750 for 480 mi one-way Sacramento --> QCC, so roughly $1.56 per mile. So that would be $1500 for a return trip.
The folllowing car models have this motor (location of motor in patenthesis):
Tesla Model S (rear) | 2012 - 2019(?)
Tesla Model X (rear) | 2015 - 2019(?)
Toyota RAV4 EV (front) | 2012-2014
Mercedes-Benz B-Class Electric Drive (B250e) (front) | 2014
Tesla provided 8 year unlimited milage warranty on the drive train. Most owners have had the LDU replaced 2-3 or even more times during these 8 years. After this period, the customer has to pay for swaps or rebuilds. Cost is $7k+. Thats when customer screams bloody murder. The majority of the failure may be related to the seal coolant leak and the collateral damages.
Tesla has had many version of the LDU and most cars were getting LDUs replaced every few 10k miles with regularity. One 2013 MS has had the original (don't
know Rev) to Rev K and then onto Rev Q all in 40k miles. There are some differences between all these Revs. Following is not a complete difference list.
Differences could be from
Design changes.
Different parts bin? Some left overs from prior supplier? Different remanufacturing sites internationally?
Individual rebuilder's preference (locktite to secure intermediate shaft bearing's outer ring in some gearbox but not other).
Remanufactured to newer Rev spec except for some unchangeable areas (eg an o-ring track in the bearing bore).
Just plain old inconsistencies?
Anyway, we really don't know so just summarizing all observed differences for reference.
LDUs came with all RWD Model S and Performance Dual Motor Model S through ~2020. Through end of 2014, None-performance dual motor and MX used a different smaller drive unit (SDU) which is oil cooled with less leakage problems. Tesla delivered 57k MSs worldwide. 107K cars were delivered in 2015 (mostly MS, MX started selling in 9/2015) So roughly 75k cars have LDUs and at least two thirds of those are probably in the US. When factoring in a 5 year lifecycle per LDU before replacement, that is 40 LDU replaced daily worldwide.
pg 4 of the 2014 annual report outlining 57k cars sold to date
pg 32 of the 2015 annual report outlining 107k cars sold worldwide in 2015
In US, largest market in 2015 is CA, then FL, TX, WA, IL, NY and NJ | source
Key forum information repositories:
Key information contributors:
Johan van Ravenhorst (YouTube|TMC | myRAV4EV | OpenInverter)
Anonymous contributor