With five races to go until the Chase for the Cup, and 15 drivers realistically vying for 12 spots, every mistake on pit road is magnified. The difference between who qualifies for the Chase and who drives for pride the final 10 races could come down to avoiding one of these five common pit stop mistakes.

5. Loose tire. A wheel and tire assembly can become a dangerous projectile when struck by a car on pit road. NASCAR mandates that a crew member be in control of them at all times. Tires get loose most often on the exchange between tire carriers and behind-the-wall crew members. Why? The wheel assembly is hot and the tire has a lot of bounce to it. The man servicing the car also has to focus on getting a new tire to the changer. The behind-the-wall teammate has an awkward grasp, at best, of the tire from his standing position and has to ensure that the carrier has the new tire, too. This routine is practiced, but over time exchanges by every pit crew do get bobbled at some point.


4. Drop the jack too soon. The driver’s signal to go is when his car hits the ground after the jack drops. Everyone is in tune with this and timing is part of the jackman’s mental checklist. He is watching the service work. Every man waves or puts his arms up when his particular duty is completed. There can be no delay, however, in lowering the jack. Fractions of a second make a difference when racing other teams off pit road. But sometimes the jack is dropped, the driver leaves and work is not completed. Is that fifth lug nut tightened completely? Is there fuel that didn’t quite make it into the cell and is still in the dump can? The lowering of the car needs to occur at precisely the right moment.

3. Equipment removed from pit box. Air guns, their accompanying hoses and fuel catch cans are visually dramatic examples of this problem when they get caught on a race car in motion. More often smaller tools are the culprits – usually chassis-adjusting ratchets. The ratchet extensions fit into narrow holes in the rear glass with little room to spare. They are difficult to line up when a car is stationary in the shop. Factor in the amount of choreography that happens in a 14-second stop and sometimes the tools cannot be pulled out of the car in time and the driver takes off with a stowaway. The aforementioned problem of a jack dropping too soon can cause this miscue.

2. Driver misses his marks. All pit crews practice with a driver who stops in a defined area so that people and tools have enough room to get the job done in the confines of each track’s unique pit box. Prior to each race the crew identifies the left front car corner stopping point and places tape on that spot on the ground. The sign at which the driver stops on is lined up so he pulls up to it on each stop. As long as this happens, each stop is off to a good start. Sometimes a driver can miss when a car that is pitted directly behind him crowds his path, creating a chicane and altering his own trajectory. Other drivers are trying their best to make up time, all the time, and lock up the brakes at the last instant, sliding off the crew’s target.


1. Dropped lug nut. There are five of these potential problems for every wheel that is changed. Approximately two hours before the green flag, crews begin to glue lug nuts to wheels in preparation for the day’s tire changes. A weather-strip adhesive is used and is the popular choice up and down pit lane. Particular tire sets are planned in a certain order during the race. Gluing lugs too early will result in the adhesive becoming brittle and a lug falling off a wheel during a stop because the adhesive breaks. Gluing lugs too late results in the adhesive not fully curing and remaining gooey. Lugs can fall off wheels. This looks like a hot piece of pizza cheese. In a perfect world the air temperature and humidity would be identical every week and the chemical properties of the adhesive would remain unchanged over time. Lugs can fall off on the best pit crew on the best pit stop of the best race team.


That’s racing. 

(Patrick Reynolds is a professional racing mechanic who has worked for several NASCAR teams.)

Related links:
Five most important races remaining on Cup schedule
Top 10 NASCAR one-hit wonders