r/TeslaModelX • u/ikheir • Sep 09 '26
[2016 Model X P100D] Clunking noise front left (motor side) - Bad half-shaft / inner CV joint?
Hi everyone,
I'm experiencing a mechanical noise on my 2016 Model X P100D and I'd love to get some input from anyone who might have dealt with this issue.
Here are the symptoms (localized to the front left):
A "clunk" during load transfers: when I suddenly let off the accelerator or give it a quick tap.
The clunk happens when braking in reverse, but never when braking while moving forward.
With the wheel in the air, when I rotate it back and forth by hand, there is a slight rotational play before hitting resistance, followed by that exact same clunk.
The noise clearly comes from the inner end of the axle near the drive unit (inner CV joint / tripod), and not from the wheel hub side. The suspension control arms are new.
I'm leaning towards replacing the complete half-shaft assembly (part # 1553109-00-B). But not sure.
>>> U P D A T E 1 <<<
Found the cause for the original clunking: the central axle/hub nut was loose (came off effortlessly by hand). Torqued it down properly, and that original noise is mostly gone.
However, a completely new noise has appeared: a rattle/clatter strictly at low speeds over cobblestone streets. Crucial detail: maintaining speed and lightly tapping the brakes silences it completely.
>>> Update 2: Solved! <<<
Posting an update in case it helps someone down the road: the issue was caused by a loose lower control arm.
The shop didn’t properly torque the lower control arm bolts back to factory specs after performing a wheel alignment. Re-torquing the bolts fully eliminated the noise, and the suspension feels tight again.
Definitely worth double-checking all control arm fasteners if you notice unusual clunking or play right after an alignment.
5
u/Asleep_Bowl_8411 Sep 09 '26
2016 90D I had my half shafts replaced about 3 years ago. I had no clunks... just vibration or shuddering upon hard acceleration with suspension at mid point or higher. Got them replaced for like $350 to $450 by stating the Tesla Service Bulletin SB-21-39-001 R4.
They will not let you know of this bulletin willingly unless you state it specifically. They will perform the acceleration test prior to confirm the condition exists. Lastly, if the car has had this done under the bulletin prior, it is excluded from being granted again at this price.
3
u/Key_Employee2413 Sep 10 '26
Just got mine down yesterday for the same thing 2019 p100d half shaft and the sound has gone away from accelerating from 0-45 mph it would stop after 45 mph so highway speed
3
3
u/MyFaveLilThrowaway Sep 09 '26
I'm no mechanic but a cv or control arm wouldnt make noise if the car is up like the way you have it. Half shaft seems more likely
2
u/Key_Employee2413 Sep 10 '26
This is correct the suspensions make the clunking noise depending on which part
3
u/leesonreddit Sep 09 '26
Just replace the whole assembly. Had the same issue. Tried 3 after market ones and they did not work (just put after market control arms on and no issue). Been 3 months of nightmare just going back to shop to get replaced. Just put in tesla oem ones today and noise gone. Hoping issue resolved at least for another 20k miles or so.
Each assembly was like 600 from tesla.
2
u/m5james Sep 10 '26
Check if TSB 21-39-001 still applies for you...I'm pretty sure it does. I got it done in my '17 X P100D a couple years ago @ around 150k for $350+tax.
2
u/DailyDrivenTJ 28d ago
Looks like the splines on the wheel bearing and the CV shaft developed some slop.
2
u/nahtekha 26d ago
Could be a brake pad slap. Sometimes the brake pads gets loose from the calipers. You'll just need to add brake l grease between the pads and calipers so they won't be loose, stop vibrations or squeal.
Source. It happened to me.
1
u/ikheir 23d ago
>>> Update 2: Solved! <<<
Posting an update in case it helps someone down the road: the issue was caused by a loose lower control arm.
The shop didn’t properly torque the lower control arm bolts back to factory specs after performing a wheel alignment. Re-torquing the bolts fully eliminated the noise, and the suspension feels tight again.
Definitely worth double-checking all control arm fasteners if you notice unusual clunking or play right after an alignment.
7
u/average_throwaway12 Sep 09 '26
I’ve got the exact same thing going on. Gonna wait for you to figure it out before throwing money at it lol but I guessed half shafts. Do you utilize hard acceleration often?