Jebinc’s Plaid Vibration Experiment Results!!!

[Donsla MS]

The 4th time they replaced my shafts, they shimmed the front motor down about 1/2".

Interesting! The fact that technically, Tesla modified a factory built car to try and address a reoccurring problem is very telling!
First, I commend the shop employees and their manager for going outside the factory "box" to solve this problem.
Second, based on the Munro video and frequent freezing frame by frame, I still see only three motor mounts high above the DU output - driveshaft interface. My thoughts? Regardless of any potential over angling of the CV joint, an additional motor mount is needed. I would place this additional mount below the DU output, opposite of the existing mounts. Up to the 2020 Model S, a six ball Rzeppa joint is used. I can only assume the 2022 model S uses this same CV joint good for a total 55 degrees.. More to come!

 

[jebinc]

Interesting! The fact that technically, Tesla modified a factory built car to try and address a reoccurring problem is very telling!
First, I commend the shop employees and their manager for going outside the factory "box" to solve this problem.
Second, based on the Munro video and frequent freezing frame by frame, I still see only three motor mounts high above the DU output - driveshaft interface. My thoughts? Regardless of any potential over angling of the CV joint, an additional motor mount is needed. I would place this additional mount below the DU output, opposite of the existing mounts. Up to the 2020 Model S, a six ball Rzeppa joint is used. I can only assume the 2022 model S uses this same CV joint good for a total 55 degrees.. More to come!

Anyone know if the 2022s and recent builds still have the vibration issue, or is this affliction limited to 2021s? Key piece of data that is very much needed.
Edit: Anyone with a recent build here have this vibration? If so, please let us know.

 

[jebinc]

2/23/22 Update:

23 degrees this morning, so I took my .7” lowered Plaid out for another vibration test run and had no vibration. Will do more testing today and will advise.

At this point, we need to confirm my results by finding a volunteer, with this vibration, to purchase and install a set of @N2itive RSX-2 Plaid Links and run the same experiment, same settings.

So, who here will step up and take one for science?!

@WilliamG @EndlessPlaid @lbowroom @N2itive@SignatureSales @GroovaEV @uthatcher @sorka

 

[n2mb_racing]

2/23/22 Update:

23 degrees this morning, so I took my .7” lowered Plaid out for another vibration test run and had no vibration. Will do more testing today and will advise.

At this point, we need to confirm my results by finding a volunteer, with this vibration, to purchase and install a set of @N2itive RSX-2 Plaid Links and run the same experiment, same settings.

So, who here will step up and take one for science?!

@WilliamG @EndlessPlaid @lbowroom @N2itive@SignatureSales @GroovaEV @uthatcher @sorka

I might volunteer. I'm going to wait until they replace my half shafts, then install the lowering links. Then hope it doesn't come back...

 

[jebinc]

I might volunteer. I'm going to wait until they replace my half shafts, then install the lowering links. Then hope it doesn't come back...

Thanks, but I need a volunteer that will put the links on while they still have the vibration. To confirm the links reduce or eliminate the vibration. Then, feel free to get new shafts - if you can. Tesla won’t give me a second set of shafts, claiming the current policy is that this vibration is normal and no repairs are recommended. If they replace your shafts, we want to know about it!

 

[n2mb_racing]

Thanks, but I need a volunteer that will put the links on while they still have the vibration. To confirm the links reduce or eliminate the vibration. Then, feel free to get new shafts - if you can. Tesla won’t give me a second set of shafts, claiming the current policy is that this vibration is normal and no repairs are recommended. If they replace your shafts, we want to know about it!

I guess I could install them before the service to try and then raise the car back up later....

 

[Donsla MS]

I guess I could install them before the service to try and then raise the car back up later....

That's the spirit!

 

[Donsla MS]

This is from Rock Auto for a 2020 MS as this is as new as they go. This shows the six ball set up used in the inner CV joint discussed earlier. Would be interesting if someone with a new MS could crawl under their car with a digital protractor and actually measure the angles? I know, fat chance as one would need access to a four post lift to have weight on all four tires for static simulation...
The total limit angle is supposed to be 55 degrees but only half of that is of concern being 27.5 degree max downward angle from differential unit to wheel hub. Just think about the amount of pressure on these balls, even when divided by six, from the torque of the Plaid! Truly ludicrous!

 

[selfbp]

I’ve got the links and confirm vibration is still there when dropped 1” on lowest setting

Also still present on 1.5” drop. I had slight vibration prior to lowering, it hasn’t gotten worse in the past month since install I will say

 

[jebinc]

View attachment 772942
This is from Rock Auto for a 2020 MS as this is as new as they go. This shows the six ball set up used in the inner CV joint discussed earlier. Would be interesting if someone with a new MS could crawl under their car with a digital protractor and actually measure the angles? I know, fat chance.
The total limit angle is supposed to be 55 degrees but only half of that is of concern being 27.5 degree max downward angle from differential unit to wheel hub. Just think about the amount of pressure on these balls, even when divided by six, from the torque of the Plaid! Truly ludicrous!

It’s the balls, races and spline that get damaged (bottom right in picture).

@WilliamG

 

[jebinc]

I’ve got the links and confirm vibration is still there when dropped 1” on lowest setting

@selfbp Still there as no change or still there but less? How damaged were your shafts to start with, vibration wise?

Edit: I see you are not reporting on a refreshed MS / Plaid vibration, which is what this thread is about. Legacy MS shutter is widely discussed in other threads.

 

[jebinc]

I’ve got the links and confirm vibration is still there when dropped 1” on lowest setting

Also still present on 1.5” drop. I had slight vibration prior to lowering, it hasn’t gotten worse in the past month since install I will say

I see (from your signature) you are not driving a vibrating refreshed model s. This thread is for the refreshed MS and Plaid as the vibration is different from the legacy MS “shutter”.

 

[n2mb_racing]

View attachment 772942
This is from Rock Auto for a 2020 MS as this is as new as they go. This shows the six ball set up used in the inner CV joint discussed earlier. Would be interesting if someone with a new MS could crawl under their car with a digital protractor and actually measure the angles? I know, fat chance as one would need access to a four post lift to have weight on all four tires for static simulation...
The total limit angle is supposed to be 55 degrees but only half of that is of concern being 27.5 degree max downward angle from differential unit to wheel hub. Just think about the amount of pressure on these balls, even when divided by six, from the torque of the Plaid! Truly ludicrous!

I don't think the wheel torque from the plaid is any higher than the previous generation P100DL. If anything, it's actually slightly lower. You can see from the graph below that the slope of the HP curve at low speeds is lower than the 2019 Raven performance. That part of the curve is where the performance is limited by motor torque. It is essentially constant motor (and wheel) torque until about 50 mph. Then above 60 mph, it is HP limited by the peak discharge capability of the battery.

Now that I am looking at this curve again, though, I am noticing what is different from the Plaid and the prior generation is the torque between 40-60 MPH is substantially higher than previous generations. And that is exactly where this problem manifests. So, maybe previous generation didn't damage half shafts this way before because they never experienced this much torque between 40-60 rpm, where the harmonics setup this vibration? I don't know. But, the raw peak wheel torque that the half shafts have to handle is actually lower on the plaid...

 

[mswlogo]

I’m due to receive my Model S in 2 weeks.
This is B.S. this problem has existed for 5 or more years. My Raven X has it. Not buying another Tesla until they fix it.

 

[n2mb_racing]

I’m due to receive my Model S in 2 weeks.
This is B.S. this problem has existed for 5 or more years. My Raven X has it. Not buying another Tesla until they fix it.

Well, it's a different problem than the Raven half shaft vibration. Maybe related, but it occurs under very different conditions. I would reject delivery and wait before picking up your S. Especially with the new headlights and tail lights right around the corner. The headlights on the S currently are terrible compared to the model 3, even the old 2018 Model 3. Just tell them you will be out of the country and can't take delivery.

 

[mswlogo]

Well, it's a different problem than the Raven half shaft vibration. Maybe related, but it occurs under very different conditions. I would reject delivery and wait before picking up your S. Especially with the new headlights and tail lights right around the corner. The headlights on the S currently are terrible compared to the model 3, even the old 2018 Model 3. Just tell them you will be out of the country and can't take delivery.

Tesla already cut over on headlights on new VINs. No VIN assigned yet. I’ve had a Model 3 and a Model X and think headlights are better on the pre-refresh X (same headlight as S).

So how many years shall I delay delivery for this different but related vibrating drive shaft issue?

 

[n2mb_racing]

Tesla already cut over on headlights on new VINs. No VIN assigned yet. I’ve had a Model 3 and a Model X and think headlights are better on the pre-refresh X (same headlight as S).

So how many years shall I delay delivery for this different but related vibrating drive shaft issue?

Hmm. Maybe the plaid got new terrible headlights? My 2018 Model 3 has more even, brighter headlights than my 2021 Plaid S. The beam has all sorts of hot and dark spots.

I'd definitely check the car before accepting delivery to make sure you get the new projector lights.

I don't know about the vibration, especially since you won't be able to feel it at delivery. It seems to start around 1000 miles after delivery.

I'm going to try the lowering links to solve it. Hopefully that works for me too.

 

[mswlogo]

Hmm. Maybe the plaid got new terrible headlights? My 2018 Model 3 has more even, brighter headlights than my 2021 Plaid S. The beam has all sorts of hot and dark spots.

I'd definitely check the car before accepting delivery to make sure you get the new projector lights.

I don't know about the vibration, especially since you won't be able to feel it at delivery. It seems to start around 1000 miles after delivery.

I'm going to try the lowering links to solve it. Hopefully that works for me too.

Lowering links is a bandaid. As it is I’m pushing it going from X to S regarding clearance in snow and mud season. Not sure highest setting will be enough on the S vs X. I occasionally need it on the X.

 

[lbowroom]

The part I struggle with in this hypothesis about CV joint damage causing the vibration is this. Wouldn’t damaged shafts and CV joints be worse under stress and full load and not just in a small speed range under low throttle?

 

[n2mb_racing]

The part I struggle with in this hypothesis about CV joint damage causing the vibration is this. Wouldn’t damaged shafts and CV joints be worse under stress and full load and not just in a small speed range under low throttle?

Well, if the CV joints have stretched and have slightly more play, under light load they could vibrate from alternating between loaded and unloaded. Under heavy load, the torque from the front motor might keep the slack in the joints pinned tightly, preventing the vibration.

If that were true, then it might indicate that a software fix is possible. The solution would be to put a little more torque on the front motor under light load, to keep the CV joints from vibrating.

Well, now, come to think of it... We could test that using track mode. Hmm. Just adjust bias between front and back motors and see if the vibration goes away. I'll have to try that later today.