Every now and again while braking, my car will pull to the left. Anyone happen to know what's wrong?

 

it happens when you brake really hard... it is torque steer since our car is usually not going perfectly straight. You need to grab on the steering wheel really tight.

 

probably not torque steer. torque steer is what happens when one drive shaft is shorter than the other, more power tends to travel the shorter shaft and it will pull the wheel in that dirrection (under accel).

braking problems? hmm, are you stopping on un-even surfaces? like is there a dip in one side of the road when you are braking, the wheel will jerk quickly in the dirrection that the dip is and you will have to hold steady.

if it is something constant, you may have a problem with your braking system, one of your calipers is frozen, clogged lines etc. frozen caliper will tend to be a constant problem, a clogged line, depending on how clogged it is, may just be under hard braking, or any time you brake. it is best to bring it to a shop you trust and have them diagnose it. braking is the most important part of a car, and if that gets screwed up by you not fixing it propperly, or a shop with dumbbutts working is not what you want to do with your car.

safety is key, don't skimp on money in this department.


[Modified by samagon, 9:56 PM 11/3/2002]

 

torque steer happens becuase the turning point is not on the drive line. Not because of shaft diff. It can happen in any kind of acceleration. Braking is also considered negative acceleration.

If you want to read up on torque steer, go to autozine, they can explain better than me.


[Modified by RedGSR, 5:27 AM 11/4/2002]

 

http://autorepair.about.com/library/...bldef-763a.htm
TORQUE STEER
Definition: The annoying tendency of some front-wheel drive vehicles to pull to one side when engine torque is applied. In other words, you step on the gas and the car wants to steer right or left. By redesigning the power train to use equal length half shafts between the transaxle and wheels, the tendency towards torque steer can be greatly reduced. The other cure is to keep off the gas.

this is what most people think of when torque steer is mentioned.

here is the article from your website..

http://autozine.kyul.net/technical_s...handling_6.htm
If the car is FWD, the steering offset D will introduce torque steer. This is because the tractive force will try to pull the center of contact patch of the front wheels forward, thus the wheel will rotate about the point the kingpin axle projected to the ground. The torque steer moment is the product of D and the tractive force. Therefore the amount of torque steer is proportional to D. The solution is to build more inclination to the kingpin so to reduce D. This is easy to be implemented in double wishbones suspension which is shown in the picture, but not MacPherson strut, whose kingpin also serves as spring and shock absorber. If we incline the kingpin too much, there will be too much lateral force transmit via the spring / shock absorber to the car body, thus causing shake and instability.

we are both correct.

there are two kinds of torque steer, one is a product of uneven halfshafts, and one is ultimately a result of suspension geometry + uneven roads. however the kind you mentioned doesn't effect braking at all, and isn't commonly thought of as torque steer, although it is, unless he is braking over uneven surfaces.

to better define the torque steer mentioned on autozine in a way that we can all imagine easily. take a door. push the door on the ****. it opens easily. now push the door near the hinges, it is much harder to open.

now, imagine that each time you go over a bump that the bump is your hand, and the wheel is the door. the closer the hand is to the hinge (the kingpin) the harder it will be for the hand (bump) to exert an opening or closing effect on the wheel.

we can also think of an uneven surface, maybe an asphalt road that hasn't been paved in a while. the edges of it are sagging as a result the road crown of it instead of being the 1.5deg it should be, it is about 5deg. as your rotate your car, the centerline of the wheel is moved towards the dirrection the car is being rotated towards. so on one side the distance 'D' will be farther than it is on the other side, and this will have a tendancy to pull your car in the dirrection that the road leans.

the wider your tire is the more the centerline of the tire can move, and the more pull you will feel.

most good alignment shops will align your car with road crown in mind, so that when you are traveling down a road that angles at 1.5deg you can release your wheel and you will travel straight.

anyway, HTH your understanding of both kinds of torque steer a little better.