Drive Unit Replacement Poll

[evp]

I went in for my appointment to get the Drive Unit replaced this morning. They said "Oh, no, we can't do that. We don't have any drive units." I asked why they would tell me I need a new drive unit and then fail to have one when I show up for my appointment. The service manager said "Nobody in the U.S. has any drive units. They've been embargoed. I think there are 20 of them in Norway." OK, so why is that? He doesn't know. I pointed out that it reflects poorly, not only on him personally and the service center, but on Tesla the company, that they don't have the part available to fix the issue.

So, we went out and drove the car on a quiet street while a tech stuck his digital recorder out the window to get a clean recording of the milling noise, in the hopes that engineering department back at the mother ship might boost the priority of replacement when DUs become available again.

Speculation on WHY there are no DUs available? I'm sure conspiracy theories will come fast and furious ("They need all the DUs on the planet to support the Model X release." "Something happened on the production line and they can't manufacture DUs fast enough to keep up with the production rate." "It's Obama's fault. Somehow.") My personal most-likely scenario: they've finally figured out what's causing the problem, and there's been enough bad press that they don't want to install even one more DU that will eventually fail. So they're pulling them all back to open them up and replace the defective part, and we'll see them popping back up at Service Centers "real soon now".

 

[ohmman]

Speculation on WHY there are no DUs available? I'm sure conspiracy theories will come fast and furious ("They need all the DUs on the planet to support the Model X release."

I have to say it's disconcerting, to say the least, that two forum members have been denied drive units they expected. The phrasing at my SC struck me as odd as well, when I dropped the car off. They said something like "we received 4 drive units, and they'll be allocated by VIN. We believe you should get one of them." Well, my appointment was specifically for the drive unit. Why else did I show up? This seems to somewhat echo evp's experience, though I was fortunate enough to receive my drive unit (installed today).

It will be interesting to see if this continues.

 

[tinm]

@evp, was your appointment at the Denver service center?

I just had a drive unit replacement done there . . . on Saturday. Maybe I got the last drive unit? They never mentioned anything about there being a shortage or an embargo. They just determined I needed a replacement, and presto.

 

[pgiralt]

@evp, was your appointment at the Denver service center?

I just had a drive unit replacement done there . . . on Saturday. Maybe I got the last drive unit? They never mentioned anything about there being a shortage or an embargo. They just determined I needed a replacement, and presto.

If you have a copy of your invoice, what was the part number for the drive unit they used as your replacement?

 

[tinm]

If you have a copy of your invoice, what was the part number for the drive unit they used as your replacement?

Right from the repair order:

Any significance to that part number? Good? Bad?

 

[gene]

I was told today drive units will arrive in 3 weeks. The milling noise people speak of is annoying but will not result in the car becoming immobile. It's just a sound, so not a high priority at the moment. The hypothesis that the Model X is requiring all drive units that they have is possible. If one's car wasn't drivable or dangerous, that would be a problem to be upset about but the bit of noise, a small fraction of what an ICE makes, I'm going to be be patient about.

 

[Maaz]

had mine replaced at about 26k miles for the buzzing noise. they told me it will most likely come back.

 

[hpham007]

The hypothesis that the Model X is requiring all drive units that they have is possible.

This maybe possible but unlikely. They can't use remanufactured drive units in a brand new car. Also, the X is heavier and with the claimed 10,000 pound towing, the drive units in the X will face way more stress than in the S. If they use the same DU, I can't see them lasting very long.

 

[Forty Creek]

had mine replaced at about 26k miles for the buzzing noise. they told me it will most likely come back.

And so they will replace it again when it does?

 

[yobigd20]

this tells me that they either don't know what's causing the issue or they don't know how to solve it.

^^^^ definitely this.

 

[yobigd20]

Right from the repair order:


View attachment 90222

Any significance to that part number? Good? Bad?

Looks new , version N, not remanufactured.

 

[mknox]

They never mentioned anything about there being a shortage or an embargo. They just determined I needed a replacement, and presto.

My Service Center told me that they were working through a list of "proactive replacements" on certain cars that had been flagged as needing new DUs. I thinks that's Tesla-speak for "Recall". Since my "buzzing", "milling noise" or whatever you want to call it is only "cosmetic", I would be lower on the priority list, but would get it done. They told me that the majority of DU problems are with the P models, and since mine is a non-P 85, I might have a part sooner.

 

[shelbri]

I believe I have the same milling noise and had it reviewed with the Service Center this Monday. They indicated it was considered "normal" but that if the volume or pitch changed, I should again bring it to their attention. They also indicated that the sounds were recorded and sent to Fremont for the engineers to review against known noises to ensure it is the same issue. They indicated that it will not impact usability or performance but Tesla is reviewing and may introduce a revision or potentially just add additional noise insulation. Either way, since I have now registered the issue with my car, I am covered for anything that may develop in the future.

 

[apacheguy]

What causes the milling noise?

 

[mknox]

What causes the milling noise?

To me, it sounds electrical. I imagine it is loose windings, likely in the inverter, vibrating to the frequency of the alternating current passing through.

 

[evp]

I'm voting against electrical, because I expect the same thing would happen during regen, or in reverse, if it was electrical. In my experience, that never happens.

 

[qwk]

What causes the milling noise?

It's supposedly caused by arcing going through the rotor bearings. Fix is replacement DU.

The other noises are,

Clunk=> not enough grease on rotor spline. If it gets bad enough, the spline strips, and car won't move when power is applied, and grinding noise is heard. This is what most DU failures are attributed to.

Drone=>improperly setup gearbox. The SC fix is shims inserted through the axle shaft holes.

 

[apacheguy]

It seems to me these explanations of the milling noise would impact performance and efficiency, no? Maybe to a lesser extend WRT loose windings but still.

 

[ohmman]

I received my freshly repaired car back today. RMN drive unit, nice and silent. Warranty note mentioned 'excessive milling noise', which I guess indicates there can be less than excessive noise by Tesla's standard(as some have encountered in this thread.)

I asked my advisor about the 'quarantine' and he indicated there was a new, better fix in the pipeline. For whatever that's worth.

 

[mknox]

I'm voting against electrical, because I expect the same thing would happen during regen, or in reverse, if it was electrical. In my experience, that never happens.

My first unit was replaced due to a loud low frequency hum that occurred under both power and re-gen, but not at zero power. My current one has the high frequency buzz but only under power. The thing is, the noise goes away if I modulate the pedal so power is zero, then comes back as I press down, even though the car remains in motion. If it were mechanical, I would expect the noise to be there all the time since mechanically, the wheels are always connected to the spinning motor and reduction gear.