Gadgetory

how many times he brought your car in for a front-end alignment and weren't entirely sure what was going on the car came out probably driving straighter and you were told it was gonna wear the tires less but in the middle there was kind of a black box so let's sort that out by introducing you to the big three of alignment camber caster and toe to help us I've enlisted the guy whose shop has done dozens of alignments on my car's ron Vasconcelos of dependable tire and brake in San Rafael California all right Ron first of all tell us what is toe that's the people mostly think of when their tires are out of alignment tow in tow out pigeon-toed duck toes yep okay okay toe Ian is going to wear the tires on the outside edge yeah toe out just gonna wear the tires on the inside edge so when your tires are kind of towed in pigeon-toed the outsides wear out more crack because we're kind of scrubbing as you draw exactly but why do you tow wheels in or out at all well you're pretty much toe in because you have friction as the car rolls down the road friction is pulling them apart okay as all the bushings move and all that kind of stuff if it's towed in you tow it in just a little bit and it toes out to about zero obviously everything gets pulled back by all the motion everything gets pulled back by them somewhat by the motion obviously some suspension systems are tighter than others old front-wheel drive cars used to tow them out because the wheels would pull them in Oh from the tour from the torque pulling it in so if your towed out or if you're not totally you're gonna have less forward stability you're gonna have you have tow out the car wants to turn on siddhart one dart right so if you're going down the freeway the car wanders just wandering a bit yeah it might have some toe out okay so let's now go to camber this is one people often misunderstand what is negative and what is positive camber negative camber the tire is leaning in at the top so it's squatting a little typically if you look at an old Volkswagen the rear wheels have negative camber a lot of it right Porsches these days have a lot of negative camber so when you have a lot of negative camber you're getting what benefit you're getting cornering benefits gonna handle better I dive into that corner that thing is kind of higher plant instead of leaning over positive it's gonna want to roll the other way so you're kind of pre setting it for the dig that's gonna get into the road and also if you're not driving the car hard you're just driving it back and forth down the freeway while the tires already sitting that way it's gonna wear an inside edge okay so it's a waste of performance if you really have an extreme negative camber correct okay so then the one that's trickiest of the of the big three is caster I still struggle with this one a little bit how do you describe caster to someone casters the angle between the upper ball joint and the lower ball joint with the lower ball joint leading that would be positive caster this is front of the car yeah the blower ball joint or the lower pivot of the steering of the steering okay forward is positive caster so that's like a bicycle fork correct and that is for what purpose why isn't that straight up and down stability a straight up and down caster angle would make for a wheel that nervously tracks left or right at almost any whim or input a little positive caster or leaned back in the angle the wheel pivots along calms this down a car will pull towards low caster say you have four degrees on the right side and three degrees on the left side the car is going to want to drift to the left because think about it the ball joint is going backwards it wants to go that way and all this stuff interacts car pulls towards negative caster pulls towards positive camber so you can have one one way and one the other in the car will drive straight where they're both over there go faster at now of these three why do they go wrong these are all big metal parts in here and people look at it so how could that every but well a lot of parts these days are made of aluminum yeah aluminum soft they do like aluminum because it's lighter weight aluminum is stronger per pound than steel but but easier to bend couple that with low-profile tires to transmit more Road impact to those aluminum parts and the fact that the joints and mounts that hold your suspension in place where and then allow things to drift and that's why you need an occasional realignment so when someone hits a pothole should they be concerned and if so why number of different things you can bend a wheel you can and suspension parts you can break the bead and attire you see a lot of people with bulge on the side of it what's happened is they've hit something so hard that it's broken the belts in there if I've hit something and I'm not sure if it did any damage or there any telltale things like can look or feel for um Sharon was straight before when I was going straight now the sharon wheels off while you're going straight while you're going straight it's something got bent give away shake now i hit that pothole now my car shakes is i'm doing 60 miles an hour down the freeway possibly been a wheel something like that many of us only get our cars aligned when we get new tires but notice things like pole or vibration is you drive a sign that things aren't aligned anymore and potentially costing you some tire life handling quality maybe even a little fuel economy more car tech demystified right now at see net on cars calm click on car tech 101