Q: My wife is 5 feet 2 and has a driving posture that places her about 12 inches from the steering wheel of her 2010 Subaru Forester, even with the pedal extenders I have installed. Years ago I was convinced that this is pretty dangerous given the geometry and violence of airbag deployments. Should I be concerned about the risk of injury from a deploying airbag?
A: The basic rule of thumb is a minimum of 12 inches between the driver’s chest and the steering wheel/airbag. The crash management system in modern automobiles is engineered to make sure the sea belt/restraint system prevents the driver’s upper body from entering the “zone of deployment” prior to the airbag inflating.
So in this case the seatbelt is the critical factor. The good news is that her Subaru, like many modern vehicles and unlike many early-generation airbag-equipped vehicles, is equipped with front seatbelt pretensioners that will rapidly retract and lock the seatbelt in any frontal collision that triggers the airbag. The mechanism for this is an “explosively expanding gas” driving a piston that retracts the belt. This helps preventing “submarining” — sliding downward and forward in the seat — and helps prevent the upper body from reaching the airbag’s zone of deployment.
It would appear that you’ve done everything possible to allow the Subaru’s crash management system to work properly for your wife in the event of a serious frontal impact.
Q: Some new cars do not have much space around the tire in the wheelwell, which results in snow collecting and freezing in the small space. Could this affect how the brakes work?
A: Very unlikely. As long as the wheel can roll, the hydraulic pressure applying the brake pads against the rotors will force out moisture and debris as well as generating more than enough heat to melt any ice/snow in proximity. With that said, it’s always a good idea to knock off the large “icebergs” that collect at the rear of the wheelwells before driving. These can initially limit steering until worn or knocked clear.
Q: I have a 2002 Buick Century with about 180,000 miles on it. The transmission shifts smoothly when it first starts but after driving for a while it starts to “clunk” when shifting to the next gear. The transmission was rebuilt in 2010. Transmission “conditioner” was added a couple of weeks ago and it’s a little better, but not much. Any suggestions for eliminating the clunk except a $2,000 rebuild? Our son will be driving the car over the summer and we’d like it to last a while longer.
A: Does the “Service engine soon” light ever come on when the harsh shifting occurs? Hard upshifts or downshifts can be indicative of “limp” mode operation — a self-protective, high hydraulic pressure mode to prevent slippage/damage to the transmission. If so, a diagnostic scan tool may pinpoint the problem.
If no service light comes on, the problem may be mechanical. Even though the transmission has apparently been rebuilt, sediment or worn/binding valves or accumulator pistons may be causing the symptom. This might explain the temporary improvement from adding the conditioner. If the additive wasn’t SeaFoam Trans-Tune, give this a try.
Recognize that harsh shifts aren’t necessarily damaging to the transmission or drivetrain. Short of major work, I’d suggest continuing to drive the car until the symptoms worsen significantly. More gentle acceleration and/or manually upshifting/downshifting the transmission may improve shift quality.
Motoring Note: A hearty “thank you” to the armchair quarterbacks who commented on my response to the faulty fuel pump on the 2000 Ford Explorer that wouldn’t start in cold weather unless the owner tapped on the bottom of the fuel tank. In describing the additional amperage drawn by a worn/tired fuel pump, I should have said higher mechanical rather than electrical resistance. The additional mechanical resistance in the pump is what causes the increased draw of current I described.