Hammering Panels And Installing Missing Suspension Bolts: Tesla’s Repair Guidelines Are Insight Into Its Manufacturing Problems

Illustration for article titled Hammering Panels And Installing Missing Suspension Bolts: Teslas Repair Guidelines Are Insight Into Its Manufacturing Problems

Illustration: Jason Torchinsky/Tesla/NHTSA

We’ve heard it endlessly, and it’s still true: Making cars is hard. One of the ways this message is delivered to the masses is through the reports of manufacturing glitches, sometimes as recalls. For smaller issues, reminders may come in the form of Technical Service Bulletins, documents that car companies create to provide repair instructions for those issues.

TSBs often give us an idea of where things went wrong or were missed during production. We’ve explored TSBs for vehicles like the Alfa Romeo Giulia in the past as a way to try to get a better idea of why owners and members of the media were experiencing issues with the car. Let’s take a look at some Tesla bulletins relating to the Tesla Model 3 and Model Y to get an idea of the problems Tesla has been seeing in vehicle production.


One of the most recent bulletins for the Model 3 is SB-20-16-003, which instructs service centers to look for missing bolts on the busbars for the high-voltage battery that powers the drive motors. The bulletin states that “Certain Model 3 high-voltage batteries may not have a sufficient quantity of bolts for the contactor DC link busbars, which may prevent the vehicle from charging or powering properly” as these busbars connect the battery to the rest of the high voltage system.

The TSB follows up with instructions to inspect the terminals if bolts turn out to be missing, as the lack of contact may cause arcing burns on the joints or terminals. Tesla does not list the number of vehicles that may be affected, but says that the TSB applies to some Model 3s from the 2018 and 2019 model years. Technicians are asked to take photos of cars with missing bolts prior to repair.

Cars leaving the factory with missing fasteners is an uncommon issue in modern automotive manufacturing, as there are tools and procedures to prevent such issues. Most factories use nutrunners in conjunction with programmable logic controllers, or PLCs, that prevent a car from being released to the next station on the assembly line until all nuts are accounted for. Tesla makes use of some automation, but Model 3 production was also expanded at a hasty pace and came to involve a lot of manual processes, so it is not hard to see how something like this may have happened


Another TSB dives into clearance issues that might result in parts not sitting flush such as TSB SB-20-10-001, which applies to protruding charge port doors on the Model 3 and Model Y. The document instructs technicians to check the distance from the edge of the charge port door to the taillight assembly and to make a repair if it sticks out more than 1.5 millimeters.


The repair procedure involves removing the charge port door assembly along with the taillight assembly, and bending the sheetmetal behind them, either using a paintless dent repair kit provided by Tesla or a dead-blow hammer if that kit is not available. Technicians are instructed to protect the corners that are being hammered with tape in order to minimize paint damage. Once the corners are hammered in, technicians are instructed to apply touch-up paint if necessary to fix any paint damage.


Missing bolts are not just limited to the Model 3, as bulletin SB-20-31-012 for the Model Y states that some cars may have missing or loose suspension bolts, which are meant to hold the steering knuckle to the upper control arm. Since this is a potential safety issue, Tesla issued a recall bulletin, which means that all affected vehicles have to be repaired. (TSBs do not require a repair unless there is a customer complaint or a technician notices it while diagnosing another issue.) According to earlier reports, this issue affects 401 Model Ys.


One of the odder bulletins in the list applies to the whole Tesla lineup, specifically the Autopilot driver-assistance system. Bulletin SB-20-17-001 states that Autopilot could be affected by ASR-9 airport radar systems, which may cause electromagnetic interference resulting in Autopilot or camera alerts popping up on the screen.


The solution to the issue is a Tesla-developed electromagnetic interference shielding gasket that needs to be installed on the Autopilot computer in the Model S and Model X; On the Model 3, it’s installed on the main computer, where Autopilot functionality in controlled.

Monitoring technical service bulletins on the NHTSA website can be a good method of discovering common issues with a given car and learning what repair procedures look like, especially for secretive manufacturers like Tesla that seem to release repair information only where required by law.


While we said above that issues like missing bolts are “uncommon,” they’re definitely not unheard of, as Dan (we’ll keep his last name hidden), a quality engineer working for a major automaker, told us. Here are his thoughts on the suspension bolt TSB:

The thing everyone has to remember is that making a car is hard! Years of R&D, trial builds, and extensive training is no match for a line worker having a bad day and missing a bolt. These things happen. Sometimes, these are even out of the OEM’s hands as a supplier made the mistake. Missing bolts happen.

What is most concerning is that these left the plant with missing bolts that can impact the vehicle’s function. There should be some level of preventive measures to ensure parts are not missing, like marking bolts after installation/torque. The suspension service bulletin with the missing nuts is especially scary, considering the OK images don’t have any marking showing that those were properly installed. I certainly would like to not have the whole knuckle falling off the upper control arm resulting in a crash. Maybe Autopilot could handle that? /s


Dan continued, providing his opinion on Tesla’s charge port issue:

The flushness issue at the charge port is also concerning as that means somewhere in their stamping and welding processes, there is a large amount of variation. To me this says the processes are not well controlled allowing for a high standard deviation with fit and finish. It is tough to tell in pictures, but flushness concerns on the side panel like that could mean there are sealing concerns on the body in white where gaps occur between the stamped sheet metal. I think “The Drive” article on this mentioned rust on them already in that area meaning water leaks are occurring. But again, this is not unusual in manufacturing especially with new model maturation. It is unusual that these are very visually apparent problems and literally hundreds of eyes look at it without reporting the issue. Their final quality department should catch these so either their quality department is not looking for fit and finish concerns or they are finding these concerns and shipping cars without repairing them.

Overall, none of these issues surprise me. This is why OEMs who have been building cars for decades don’t have these issues nearly as much as Tesla. It takes time to learn from mistakes. You can have manufacturing experts on your team from the best companies in the world, and at the end of the day, they can’t control all of the variables that go into automotive manufacturing. Murphy’s law strikes again!

To me, these issues making it to market is the real concern for Tesla as it proves that they are more concerned about selling cars than building high quality cars. This makes them money in the short term. And clearly, they still are selling to a blissfully ignorant audience that is more happy to be behind the wheel of new tech than a good car. However, with the established OEMs catching up with EV offerings, I think that will really hurt Tesla’s reputation. Once you get past the Tesla cult, the average consumer will want a higher quality vehicle. If Tesla’s vehicle quality does not improve, they will hurt in the long run.


It’s worth repeating that this is one opinion from a manufacturing engineer working for a competing car company. Still, it’s always good to have input from engineering experts on these types of things. It’s also worth noting that Tesla boss Elon Musk himself admitted in a recent interview with engineering consultancy Munro & Associates that Tesla has struggled with manufacturing, especially as the company rapidly ramped up vehicle production.

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