Drive Unit water intrusion

Drive Unit water intrusion

Has anyone had their Drive unit fail because of water intrusion? This is a replaced drive unit with only 23,000 mile. The 1st was replaced from milling noise at 47,000. I remembered passing over 4/5 inches max of standing water. The SC is claiming the drivetrain is done & not covered under warranty. Very surprised by this.. Is there a seal issue?

Boonedocks | 14 juni 2019

Just remind them of Elon saying this. Also he did not say it would void your DU warranty:

tes-s | 14 juni 2019

I guess it will come down to the definition of "brief" in Elon speak. soon

I don't know if the drive units are sealed or not - I'm pretty sure they are not supposed to get wet. 4-5" of water wouldn't even touch the battery, unless the car was set to low. I don't think that would be the problem.

Talk to Tesla again. If they don't cover it under warranty, then it should be covered by your insurance company.

procarl | 14 juni 2019

My first failed DU occurred at approx. 40,000 mi; cause: "Water in Drive Unit". Replaced with no questions asked. 2nd DU failed at about 68,000; again replaced, although cause was not indicated. Now at 117,000 mi with no further issues.

Silver2K | 14 juni 2019

Tesla does not have to replace the DU under warranty, because seals are wear items and it would take a seal failure to cause the intrusion.

jordanrichard | 14 juni 2019

Ummm, the driveunit is warrantied for 8 years, regardless of miles. 4-5 inches of water would not reach the DU. You don’t say what the issue is. What exactly happened?

viranjit | 14 juni 2019

My first drive unit was replaced at 20K mules due to a milling sound in March 2014.
Last month the drive unit was replaced at 76K miles due to "fluid ingress". Symptom was complete loss of power.

Replaced under warranty. I believe the drive train has an 8 year unlimited mile warranty.
2012 P85 Model S.

txakoli | 14 juni 2019

My 2014 Model S DU was replaced at 24000 miles due to “milling noise”. The replacement DU lasted until 39000 vehicle miles when it was diagnosed with “fluid intrusion”. I was getting multiple dashboard alerts but I wasn't left stranded.

Both DUs were replaced under warranty. No questions asked.

ST70 | 14 juni 2019

@Silver2K- that doesn't make sense...Tesla would have to make this a maintenance item. Where are you getting this info?

p.c.mcavoy | 15 juni 2019

Silver2K | June 14, 2019
Tesla does not have to replace the DU under warranty, because seals are wear items ...

@Silver2K - So I guess you would not argue with any auto dealer if the lip seal on the crankshaft of your ICE engine developed an oil leak while still under warranty.

A properly designed shaft or lip seal should not wear out for an incredibly long time. Most times one leaks there is an underlying issue, such as it got cocked under installation and not aligned correctly, is a concentricity or out of round condition between the shaft and housing, or a poor design that hasn't properly considered things like dust shields common on shaft lip seal used in industrial equipment.

afonse002 | 15 juni 2019

HI Jordanrichard,
I did not think my drive unit would be affected by such a simple puddle. The first thing was the warning light that stated Car needs service and car may not start showed right before reaching the mall. This happened in the highway, then drove to a busy shopping center. While standing in line to park, I was standing on a simple puddle. Then, I decided to park in reverse to do a quick errand, but the warning that the car may not start was still present. As I drove backwards into the parking space the car was kind of jerky (seemed odd), but I was not in a big puddle. I was considering getting off the car not afraid or concerned of getting my socks wet. Because of the warning, I may the decision to drive home instead. After a few hours, the car did not want to start because of not enough power to the MCU. The next day the car started and took a drive to see but the may not start warning came back on. I thought it was the 12v battery, but there was no mentioned of 12 v issue. The 12V warning came on 3 days later to let me believe that was the only issue until the car was checked by the SC. I take care of my car really well and don't do foolish acts. I feel that the DU has a seal issue.. At this point, I am trying to go with my car insurance as a last resort, but not fair...….

pgkevet | 15 juni 2019

If that seal is a wear item then why is it not scheduled for periodic inspection and replacement?

afonse002 | 16 juni 2019

I just remembered that the drive shaft seals were replaced due to a clicking sound while moving forward. The sound went away. This was about a year ago. I am going to remind them on the helpful info above & of the shaft seal replacements. | 16 juni 2019

While the drive unit is water resistant (i.e. splashes will not cause a problem), is it not waterproof. If the drive unit is submerged, water pressure may cause leaks into the electronics through air pressure seals. While normal rain, puddles, etc, would not be a concern, traveling through a flooded area has risks (on any car, not just Tesla). While 5" flooded area may seem like nothing, what will happen is the tires create a wake behind them - just like a boat. The faster you drive through the flood, the higher the wake crests. As the left/right crests meet in the center, I expect you could easily get 10-15" of water height. If there was a dip in the road surface, that 5" of water could be much higher for a short period. It might only take a few seconds where the entire drive unit is submerged.

Now there have been a few cases of people driving their Tesla through a flooded area. Some seem to be lucky and have no damage. There have been others that have the car totaled along with other ICE cars.

Now I have no way of knowing if @afonse was only going through a 5" flood, or perhaps deeper. The speed is a big factor too. Bummer to have to get a new DU, but at least it's something fairly easy to replace. I wonder if Insurance might cover it.

Silver2K | 20 juni 2019


I got that information from the mobile tech after I discovered oil on the pad under my front motor. I asked if it's covered under the motor warranty and was told seals are wear items and not covered under warranty.

rxlawdude | 20 juni 2019

@Silver, is it possible that tech was talking out of his rear?

NKYTA | 20 juni 2019

I had my traction batt replaced under warranty when I hit a large amount of thunderstorms in GA and the Carolinas in 2017 and it was determined that my 2012 S did not have the right water protection at the lead part of the battery.

This isn’t that.

Silver2K | 21 juni 2019

Rx, he may have been. After I saw st and PCs posts I decided to read the warranty and did see wear items are no other covered, but seals were not mentioned. I called into support and was told the seal is covered and not a wear part, but service has the final call. I asked for something that is written for owners to refer to in case service is wrong in their final determination.

Stay tuned :)

Silver2K | 21 juni 2019

No other/not

Silver2K | 27 juni 2019

The seal where the half shaft goes into the drive unit is not covered and is a wear part. I gently mentioned CS explained it's not a wear part l. The tech contacted the manager and covered it with another word from me. The tech said it was covered under my original warranty because it was noticed then.

Silver2K | 27 juni 2019

With/ without

ST70 | 27 juni 2019

still doesn't make sense...if it's a wear part then Tesla should have to state that it has to be inspected/replaced at a certain interval

Silver2K | 27 juni 2019

There is definitely a mix up somewhere