Drive unit problems explanation by Elon

[glhs272]

Are there any indications of this problem occurring in cars produced after they extended the warranty? If not, why does it seem to happen repeatedly to older cars even after having the drive unit replaced? If they really can't seem to solve it, that worries me much more than the problem existing in the first place.

I finally ordered a car after the D announcement, AWD and the drive unit issues being the only things holding me back, but I couldn't have imagined this still being an issue. It's scary.

Don't be scared. They have solved it. I had my drive unit replaced over 14,000 miles ago. The original unit never died and only made a slight noise like the differential gear wasn't quite shimmed properly. The replacement unit has been completely silent and working perfectly. Tesla seems to be taking a "goodwill" approach and replacing any problematic drive units that happen within the reasonable life of the car. This really isn't an issue anymore.

 

[dhanson865]

Are there any indications of this problem occurring in cars produced after they extended the warranty? If not, why does it seem to happen repeatedly to older cars even after having the drive unit replaced? If they really can't seem to solve it, that worries me much more than the problem existing in the first place.

I finally ordered a car after the D announcement, AWD and the drive unit issues being the only things holding me back, but I couldn't have imagined this still being an issue. It's scary.

Did you order a D? I'm going to assume the D is more reliable than the regular S in that having 2 motors spreads the load out, same or better acceleration but from two ends of the car instead of one meaning a reduction in how focused the forces are in the rear.

They can also let the computer reduce tempatures in the rear motor by shifting load to the front any time the rear motor gets hot. Metals tend to last longer under wear if the wear is at a lower temperature.

I'd have to assume the D configuration is superior in so many ways it would be time consuming to explain all of them. I'm going to go have lunch instead.

 

[Urtie]

Don't be scared. They have solved it. I had my drive unit replaced over 14,000 miles ago. The original unit never died and only made a slight noise like the differential gear wasn't quite shimmed properly. The replacement unit has been completely silent and working perfectly. Tesla seems to be taking a "goodwill" approach and replacing any problematic drive units that happen within the reasonable life of the car. This really isn't an issue anymore.

That's really good to hear. I should explain that I am not worried for myself (the warranty took care of that), but for Tesla. I really want them to succeed.

Did you order a D? I'm going to assume the D is more reliable than the regular S in that having 2 motors spreads the load out, same or better acceleration but from two ends of the car instead of one meaning a reduction in how focused the forces are in the rear.

They can also let the computer reduce tempatures in the rear motor by shifting load to the front any time the rear motor gets hot. Metals tend to last longer under wear if the wear is at a lower temperature.

I'd have to assume the D configuration is superior in so many ways it would be time consuming to explain all of them. I'm going to go have lunch instead.

Yes, a P85D. I agree that it might reduce wear, but it's also twice the number of potentially malfunctioning drive units. I don't believe that Tesla considers it acceptable that they have had to change them after, what seems like to me, a pretty consistent number of miles, so it just worries me if problems still exist. It would be indicative of a very hard problem to solve.

I hope we get to hear from more people like glhs272 who had their problems solved permanently!

 

[mhpr262]

What would be the trade off with straight cut gears?

A god-awful howl and whine.

 

[ModelS1079]

Don't be scared. They have solved it. I had my drive unit replaced over 14,000 miles ago. The original unit never died and only made a slight noise like the differential gear wasn't quite shimmed properly. The replacement unit has been completely silent and working perfectly. Tesla seems to be taking a "goodwill" approach and replacing any problematic drive units that happen within the reasonable life of the car. This really isn't an issue anymore.

Nearly 10 months later, I am wondering how your new drivetrain is performing. Any more sounds? Thanks

 

[supratachophobia]

Nearly 10 months later, I am wondering how your new drivetrain is performing. Any more sounds? Thanks

Id like to know as well. But also post what revision replacement he got, especially if he still isn't having problems. It's the last letter on the part number located on your repair order.

 

[glhs272]

Nearly 10 months later, I am wondering how your new drivetrain is performing. Any more sounds? Thanks

Ugh, need to totally eat my words on that post. I believe this was posted after the first drive unit replacement. When I got that drive unit, it actually seemed even better than the original unit that came with the car (smoother, quieter). That replacement was a Remanufactured Rev A unit with shim. It worked great for a good while, thus felt OK thinking the issues were fixed. Then around 24K miles after replacement a slight milling sound developed, never got very loud. When the car went in for an annual last May, Tesla says it's loud enough to be replaced. So now running a REMAN Rev M unit. I guess we will see how this one holds up. Got about 5K on it now. One thing is for sure, I won't be crowing about how Tesla has their drive unit issues resolved until I can get over 100K out of one. At my rate of 25K a year that will be a while. But I will post updates. Thus far, these have been annual drive unit replacements. So unless the drive unit quality is actually getting worse, I won't have anything to update until June 2016 to see if it is milling again by then.

 

[islandbayy]

Ugh, need to totally eat my words on that post. I believe this was posted after the first drive unit replacement. When I got that drive unit, it actually seemed even better than the original unit that came with the car (smoother, quieter). That replacement was a Remanufactured Rev A unit with shim. It worked great for a good while, thus felt OK thinking the issues were fixed. Then around 24K miles after replacement a slight milling sound developed, never got very loud. When the car went in for an annual last May, Tesla says it's loud enough to be replaced. So now running a REMAN Rev M unit. I guess we will see how this one holds up. Got about 5K on it now. One thing is for sure, I won't be crowing about how Tesla has their drive unit issues resolved until I can get over 100K out of one. At my rate of 25K a year that will be a while. But I will post updates. Thus far, these have been annual drive unit replacements. So unless the drive unit quality is actually getting worse, I won't have anything to update until June 2016 to see if it is milling again by then.

My current motor is mirroring your issues exactly. Getting my third drive unit this friday.

 

[hpham007]

Just an interesting subnote, Mercedes will stop using Tesla drivetrains:
Mercedes B-Klasse Electric Drive: Künftig ohne Tesla-Technik - AUTO MOTOR UND SPORT

 

[yobigd20]

Just an interesting subnote, Mercedes will stop using Tesla drivetrains:
Mercedes B-Klasse Electric Drive: Künftig ohne Tesla-Technik - AUTO MOTOR UND SPORT

and a different article in English, lol: Mercedes-Benz Ends Battery Partnership With Tesla Motors Inc For B-Class EV

 

[Lump]

and a different article in English, lol: Mercedes-Benz Ends Battery Partnership With Tesla Motors Inc For B-Class EV

OEMs begging to buy Tesla drive units & battery's were last years hype, we have moved on to bigger & better...Tesla will now own the shared mobility services market according to Adam jonas.

 

[AmpedRealtor]

OEMs begging to buy Tesla drive units & battery's were last years hype, we have moved on to bigger & better...Tesla will now own the shared mobility services market according to Adam jonas.

You mean the shared mobility market that will see thousands of Tesla vehicles driving themselves and their passengers around town autonomously? Pipe dream. Never going to happen. Sounds like Mr. Jonas doesn't understand technology very well. Anyone who thinks we are going to have truly autonomous cars by 2020 where there doesn't need to be a driver in full control are smoking an unusual brand of crack. Tesla will be out of business or acquired by someone else before we have true autonomy.

 

[supratachophobia]

You mean the shared mobility market that will see thousands of Tesla vehicles driving themselves and their passengers around town autonomously? Pipe dream. Never going to happen. Sounds like Mr. Jonas doesn't understand technology very well. Anyone who thinks we are going to have truly autonomous cars by 2020 where there doesn't need to be a driver in full control are smoking an unusual brand of crack. Tesla will be out of business or acquired by someone else before we have true autonomy.

This guy.... Again.

 

[apacheguy]

Tesla will be out of business or acquired by someone else before we have true autonomy.

While I highly doubt we'll have full autonomy by 2020, I'm curious as to what the basis is for your quoted statement?

 

[mknox]

While I highly doubt we'll have full autonomy by 2020, I'm curious as to what the basis is for your quoted statement?

When I was a kid in the early '60s, I was promised that flying cars would be ubiquitous and we'd have jetpacks for local trips :biggrin:

 

[Krugerrand]

While I highly doubt we'll have full autonomy by 2020, I'm curious as to what the basis is for your quoted statement?

I believe it was meant as a 'when pigs fly' type of statement. AmpedRealtor doesn't believe the world will ever see what he defines as 'true autonomy', let alone by 2020, and that there's a greater chance of Tesla being out of business or bought by another company than the former happening. Oh, and he also thinks anyone who feels differently on the topic is most surely smoking an unusual brand of crack. Of course, I may have that entirely wrong.

 

[Johan]

I'm sticking with regular crack for my weekday smoking.

 

[supratachophobia]

Tesla has never reached out to me ever. Are they only doing this in areas that are not heavily-populated by Tesla owners? It's hard enough to get a service appointment that isn't a month out, and even harder to get valet service or a loaner, I can't imagine them actively looking for more cars to work on.

They have an spreadsheet with your real-name --> username. It's updated when they figure out who you are. It's harder if you VIN number isnt in your sig obviously. They actually tracked me down by reading my post history, finding what options I had on the car (which was a rare config), and then calling up the narrowed down list (4 apparently) one by one.

- - - Updated - - -

I believe it was meant as a 'when pigs fly' type of statement. AmpedRealtor doesn't believe the world will ever see what he defines as 'true autonomy', let alone by 2020, and that there's a greater chance of Tesla being out of business or bought by another company than the former happening. Oh, and he also thinks anyone who feels differently on the topic is most surely smoking an unusual brand of crack. Of course, I may have that entirely wrong.

He isn't the only one. Johnny Cabs are not in our future by 2020 to be sure. Maybe we can get there with drive-by-wire embedded roads.... maybe.

 

[SR22pilot]

No way by 2020 but 2030 is a possibility. Google's cars are already doing an impressive job. If you look at the potential in the EyeQ 3 chip in the Model S you will see a lot of potential. Watch this video:

https://youtu.be/kp3ik5f3-2c

 

[neroden]

One platter-shaped axial ball bearing inserted between the "blunt ends" of the gear axle and the gearbox casing on each side for the axial loads, and one ring-shaped ball/needle bearing pushed over each end of the axle for the radial load ... if that is really the cause I wonder why it wasn't caught in testing. Maaybe they just varied the torque load and didn't reverse it or not often enough?

From the buildup video it looks like the deep-groove radial ball bearings in the gearbox are insufficient to carry the axial thrust loads induced by the helical-cut gear sets, especially when the torque load reverses. Some sort of bi-directional thrust bearing is needed to carry these axial loads.

This is the first plausible explanation for the recurrent drivetrain problems I've seen. This would account for:
(a) the progressive damage/wear which requires replacement
(b) the "thunk" on reversal developing as damage develops (the axial "play" increasing over time to where it allows for a sharp thunk)
(c) the "cicada" or "milling" sound at medium power levels developing as damage develops (the bearings getting damaged or out of alignment by the axial forces)
(d) the development of "lag" on reversing

Tesla Engineering, I hope you're reading this. Is there some way for someone with better contacts to escalate this possibility to Tesla Engineering to make sure they're aware of it?
Improving the support for these axial forces would probably require a fairly significant drive unit redesign, but nothing which would cost serious money in the *long* run -- and the new drive unit would probably still fit in the same space in the car, so it would be a very viable retrofit.

If this is correct, the drivetrain life can be extended by avoiding aggressive reversing form forward to reverse (or vice versa).