Large Drive Unit Milling

[TSLA_maybe]

2014 MS85...just started having the milling noise about a month ago. Didn't notice it at first until one day the music cut off and heard it faintly for the first time. It's now the very noticeable at low speed, high pitch at higher speed noise that other thread users have posted about. And as others, the car drives and works as usual. Wondering how long others have put up with the noise and just kept driving until it failed, or not fail. It hasn't annoyed me enough yet to get it replaced so thinking to just keep going until it gets to me or it fails.

Also, since its been mentioned as the supposed cause is coolant leaking, over the past 1.75 years, I've had to add some G48 every 6 months or so. In total, I've added a little over a full gallon.

 

[NV Ray]

Assuming you're out of warranty.

A true test will be checking your speed sensor for coolant. If there is coolant on your speed sensor then your choices are drive until you get alerts or address the issue now. In most cases getting alerts will result in going to Tesla for new or reman replacement ($5k-$7k with 4 yr/50k mile warranty) because some independent professionals will not address your issue as they consider your drive unit too far gone.

Or an independent professional can address now, before you get alerts. (Still around the $5k area with probably a year warranty)

If you go with Tesla, insist on latest "U" version. If you go with independent, ask about the coolant delete remedy which is the same thing as Tesla's U version.

Here's my recent post on replacing my RDU - Proactively replacing RDU/LDU

Here's how to check your speed sensor -

 

[TSLA_maybe]

Assuming you're out of warranty.

A true test will be checking your speed sensor for coolant. If there is coolant on your speed sensor then your choices are drive until you get alerts or address the issue now. In most cases getting alerts will result in going to Tesla for new or reman replacement ($5k-$7k with 4 yr/50k mile warranty) because some independent professionals will not address your issue as they consider your drive unit too far gone.

Or an independent professional can address now, before you get alerts. (Still around the $5k area with probably a year warranty)

If you go with Tesla, insist on latest "U" version. If you go with independent, ask about the coolant delete remedy which is the same thing as Tesla's U version.

Here's my recent post on replacing my RDU - Proactively replacing RDU/LDU

Here's how to check your speed sensor -

Thanks for the info. I'm now contemplating proactively replacing it if the newest version solves that coolant issue.

 

[NV Ray]

Thanks for the info. I'm now contemplating proactively replacing it if the newest version solves that coolant issue.

Both Tesla's U version and the similar aftermarket coolant delete are less than 6 months old. So not time tested. Part of the reason I went brand new replacement RDU with Tesla. At least I've got 4 yr warranty and can be one of their test cases

 

[TSLA_maybe]

Both Tesla's U version and the similar aftermarket coolant delete are less than 6 months old. So not time tested. Part of the reason I went brand new replacement RDU with Tesla. At least I've got 4 yr warranty and can be one of their test cases

I'm ok with being test case with the warranty.

 

[Usher]

2014 MS85...just started having the milling noise about a month ago. Didn't notice it at first until one day the music cut off and heard it faintly for the first time. It's now the very noticeable at low speed, high pitch at higher speed noise that other thread users have posted about. And as others, the car drives and works as usual. Wondering how long others have put up with the noise and just kept driving until it failed, or not fail. It hasn't annoyed me enough yet to get it replaced so thinking to just keep going until it gets to me or it fails.

Also, since its been mentioned as the supposed cause is coolant leaking, over the past 1.75 years, I've had to add some G48 every 6 months or so. In total, I've added a little over a full gallon.

Assuming I had the same noise as yours, I put about 4 years / 75,000 miles on my P85 since I first heard the noise. I planned to just drive on it until it failed, but ended up selling the car and upgrading to a new one when they offered the free supercharging transfer.

 

[TSLA_maybe]

Assuming I had the same noise as yours, I put about 4 years / 75,000 miles on my P85 since I first heard the noise. I planned to just drive on it until it failed, but ended up selling the car and upgrading to a new one when they offered the free supercharging transfer.

Thanks for that data point. This is what I'm thinking of doing as well...driving it until failure or if the noise gets to me. Though if this new version of the LDU resolves the coolant issue and with warranty, I may bite.

Did you have to refill the coolant during those 4 years/75k?

 

[Usher]

I never had to refill the coolant while I had that car.

 

[TSLA_maybe]

I never had to refill the coolant while I had that car.

Thanks again for the data. I'm gonna have to check coolant intrusion at some soon when the warms up a bit here in the northeast. I suspect my LDU may have the intrusion and assuming may fail sooner, so now thinking more about doing the proactive replacement.

 

[JamesMS13]

2014 MS85...just started having the milling noise about a month ago. Didn't notice it at first until one day the music cut off and heard it faintly for the first time. It's now the very noticeable at low speed, high pitch at higher speed noise that other thread users have posted about. And as others, the car drives and works as usual. Wondering how long others have put up with the noise and just kept driving until it failed, or not fail. It hasn't annoyed me enough yet to get it replaced so thinking to just keep going until it gets to me or it fails.

Also, since its been mentioned as the supposed cause is coolant leaking, over the past 1.75 years, I've had to add some G48 every 6 months or so. In total, I've added a little over a full gallon.

I’m in your same boat, 2013 Model S 60 with a replaced 85 kwh battery. Heard the milling sound in the same way as you, my music volume was low and I heard the whine. To be quite frank I have no plans of changing the DU until it takes a SH*T. I spoke with an ex Tesla tech, he’s actually worked on a lot of these pre 2016’s he said that I shouldn’t even worry about it the DU still has a lot of life in it. The sound is bugging me but I’m assuming with time I’ll get used to it maybe you will too! To me it’s not worth spending that much money on my 10 year old car I plan on selling the car in a year or two anyways. It’s really up to you if you feel like you can comfortably afford that repair I’d say go for it!

 

[TSLA_maybe]

I’m in your same boat, 2013 Model S 60 with a replaced 85 kwh battery. Heard the milling sound in the same way as you, my music volume was low and I heard the whine. To be quite frank I have no plans of changing the DU until it takes a SH*T. I spoke with an ex Tesla tech, he’s actually worked on a lot of these pre 2016’s he said that I shouldn’t even worry about it the DU still has a lot of life in it. The sound is bugging me but I’m assuming with time I’ll get used to it maybe you will too! To me it’s not worth spending that much money on my 10 year old car I plan on selling the car in a year or two anyways. It’s really up to you if you feel like you can comfortably afford that repair I’d say go for it!

That is my thoughts initially as well. However with the latest version that NV Ray mentioned with the coolant delete, I'm contemplating the replacement since I'm having to refill the coolant about every 6 months. I'm just assuming that the coolant is leaking into the LDU. Have you also had to refill your coolant in a certain interval?
I plan on keeping the car for as long as possible plus I got a replacement battery a year and half ago. I just put in a request to see what a replacement estimate cost would be around here in NY. May nudge me one way or the other. Anecdotally, today has been the warmest day (mid-60s) around here in the past months since the sound started, and it seemed not as bad, or perhaps I may be getting used to it.

 

[JamesMS13]

Welp, update… I heard the milling noise few days ago and today I woke up to head to work and received the Vehicle May Not Restart warning. Guess I’m an unlucky one, car is going into service on the 12th hopefully the DU is no more than 6k. I’ll update you on what happens, also no I’ve never had to add coolant.

 

[JamesMS13]

 

[tm1v2]

Those of you running into the milling sound now, on 1st gen RWD Model S, is this your car's first such failure, or have you experienced multiple milling sound failures over the years?

As a data point, our P85's drive unit was replaced under warranty for the milling sound around 2015-2016 if I recall correctly. It's probably been 100k+ miles on the replacement drive unit without the milling coming back so far.

 

[JamesMS13]

I went to Tesla Service today, my car is still on its original drive unit it took approximately 104,000 miles and 11 years for it to start milling. Assuming your drive unit was replaced the Model T DU you are still prone to the coolant leakage issue. The new Model U as said in this forum has the coolant delete so if we all get it replaced we most likely won’t run into a DU issue for a long time. Now as for your Drive Unit only time will tell making it past 100k miles with the first version drive units is rare. I watched a study about these DU’s and the guy said most T model Drive Units go out about every 33,000 miles, now I don’t know how much of this is true but the way you drive the car really matters on how long your DU will last.

 

[JamesMS13]

I guess tesla was feeling a bit nice? I got quoted just at the 5,000 dollar mark for a reman U model DU, I’m going to go ahead with the replacement, the fact that I am going to receive a 4yr/50k warranty as well with the replacement makes it a great choice to go ahead with the replacement. I’ll send the invoice later!

 

[maximizese]

We bought our 11/13 built S85 used from Tesla late in 2018 with 59K miles on it. Literally hours after driving the car home I got a low coolant warning, so I took the car into our local Service Center to have that checked out and have the rear window defroster replaced. Months later I noticed the drive unit was getting louder with a milling sound between 15-30mph. Months after that we started getting sporadic "car may not restart" messages that would appear and disappear within seconds and not reappear for weeks. Finally at 92K miles, the car announced that it will do a systems performance check and reboot the next time the car turns on.

After the reboot, I had various warnings from:
top speed and acceleration reduced
regenerative braking system disabled
car may not restart

Tesla Roadside advised me to drive to my nearest Service Center parking lot just in case the car doesn't start again.; it didn't. Service Center checked the logs and told me the drive unit will likely need to be replaced since it was logging impedance out of range. Tesla replaced the drive unit (Q revision), HV contactors, pyro fuse, coolant, 12V battery, and installed the HVAC drain hose retrofit all under warranty. 42K miles later everything seems fine but I'm tempted to pull the speed sensor to check for coolant.

 

[TSLA_maybe]

I guess tesla was feeling a bit nice? I got quoted just at the 5,000 dollar mark for a reman U model DU, I’m going to go ahead with the replacement, the fact that I am going to receive a 4yr/50k warranty as well with the replacement makes it a great choice to go ahead with the replacement. I’ll send the invoice later!

Wow...uncanny timing. $5k for the latest LDU version reman'd with the warranty sounds good to me too. I'm still waiting on what my svc will come back with.

 

[NV Ray]

I guess tesla was feeling a bit nice? I got quoted just at the 5,000 dollar mark for a reman U model DU, I’m going to go ahead with the replacement, the fact that I am going to receive a 4yr/50k warranty as well with the replacement makes it a great choice to go ahead with the replacement. I’ll send the invoice later!

I recently saw a $5200 (base) Tesla quote for their U sport reman. Did it go down $200? There may be a price difference between the non-sport and sport RDUs.

Pic is recent Tesla quote for both new (left) and reman (right) sport U version. I opted for a new one for $800 more.

 

[JamesMS13]

Question, Tesla just randomly made changes to the invoice. The drive unit is missing and they want me to approve this now? Is this a mistake on their end?