Acceleration Shudder On The Model S and X
While most know about the tire wear issues that the Tesla Model S and X suffer from, many all-wheel drive models also suffer from what’s become to be known as acceleration shudder, or vibration that comes from the front end of the vehicle while you’re accelerating. This problem can also present itself as clicking or clunking sound from the front, oftentimes while you are accelerating through a turn. If you don’t have the issue yet, you quite likely will so it’s critical to prevent it before it starts to avoid costly repairs. Despite how common the issue is, It’s important to note that vibration coming from the front of the vehicle could also be coming from another source such as unbalanced tires or Tesla’s built in lane-departure warning, but that type of vibration would happen at different times and not just during acceleration. If you have a vibration or shudder coming from the front of the vehicle while you are accelerating then you most likely have the common acceleration shudder problem, which is destroying your half-shafts (drive axles).
To explain why this happens, we’ll take a trip back to 2014, when Tesla added another motor to the front of the Tesla Model S to make it an all-wheel drive car. This was a great idea, except for the fact that they used the original Model S platform, which was designed as a rear-wheel drive vehicle. Tesla decided not to redesign the platform but to use the same chassis and work within the constraints of that design. This essentially meant mounting the new front motor/gearbox higher up than would be ideal for the longevity of the half-shafts (drive-axles). Mounting the motor so high up increases the downward angle of the half-shafts and therefore increases the stress and binding forces within them. With such a heavy car, high torque motors and the steep angle of the half-shafts, over time certain parts inside the half-shaft will fatigue and become marred. As the half-shafts roll over these imperfections the car will have shuddering or vibration. Ideally the half-shafts would need to be more on-axis to eliminate the cause of this issue. This issue is even more common on the X because it sits higher up and therefore puts the half-shafts at a greater angle making it more prone to damage.
Tesla does not currently have a permanent fix for this. If you have this problem right now, Tesla will replace both half shafts and also install a new left front drive unit clevis mount. This will typically solve the shudder problem for a little while but it will come back, from as quickly as 500 miles to as long as 10,000 miles. Tesla may not cover this repair under warranty, because they consider this a “wear and tear” issue. Much like worn tires not being covered under warranty, so you may have to fight for them to replace everything for free.
An online poll suggests that approximately 70% of Model X’s have suffered from the acceleration shudder issue alone. There is currently no permanent fix from Tesla. N2ITIVE ‘s Alignment Kit 1 will reduce the premature wear on your half-shafts (drive axles) to help prevent the onset of this problem. This kit allows your half-shafts to be more on-axis with your wheels to reduce binding that causes damage.
At N2ITIVE, we have engineered a kit to reduce the angle of the half-shafts which reduces wear and prolongs their life. By installing our Alignment Kit 1, also known as our Acceleration Shudder & Inner Rear Tire Wear Kit we reduce premature half-shaft wear and completely eliminate the inner tire wear problems in one shot. Installing our kit will pay for itself many times over during the time you own your Tesla in the cost of tires alone. If you suffer from the inner tire wear issue that so many of us have then you could easily double or triple your tire life, since your tires will now be in a perfectly symmetrical alignment and wear evenly. Beyond that, the safety factors alone are essential. Everything you need is included in the kit. Installation can be performed by the home mechanic or you can take it to a local alignment shop that has experience with installing and aligning adjustable control arms.
Our kit includes 3 main pieces for the 2012 -2020 models. First is a set of our RSX series ultra-precision lowering links. These allow you to easily and super accurately lower your Tesla slightly to help bring the half-shafts closer to a straight angle and reduce binding. We recommend setting them to the -4 or -5 setting. You can go lower if you want but the ride quality will suffer if you go too low. Only a slight drop in vehicle height is required to reduce wear on your half-shafts. Our links go down to -13 if you really want to go for the lowered look. Our ultra precise lowering links are easily and very accurately adjustable to allow you to set the ride height of your choice.
Also in the kit for the 2012 – 2020 models is our new SX-2 and TSX-2 adjustable camber and toe control arms. Both of these adjustable control arms are installed in place of your current rear control arms to allow you to set a perfectly symmetrical alignment. For the 2021+ model S and X Teslas the kit will come with our RSX series lowering links and our new SX-P2 rear adjustable camber arms. The 2021+ kits do not come with adjustable rear toe arms since the OEM rear toe arms are already adjustable.
The end result of having it installed is a car with significantly improved tire wear, reduced binding and wear in your half-shafts, increased firmness for far better handling and agility and improved aerodynamics. Plus you’ll get better mileage than the same Tesla without our kit. Even if you don’t yet have the common front end acceleration shudder/vibration it’s worth installing this kit to help prevent your expe
