SUCH "EASY" RACK
With the advent of the rack-and-pinion control structure, motorists immediately appreciated its important advantage - low friction losses, ease of maneuver. But this “stick” has two ends: if it is not equipped with an amplifier, the driver perceives with his own hands any destabilizing forces coming from the road to the steering wheel. It affects ruts, bumps, wind gusts, unbalanced or deformed wheels, uneven brakes, etc. In short, “easy operation” results in higher demands even on the state of the machine: what “Lada” forgives us, do not forgive “Samara "!
And now from theory we turn to practice. Trouble rarely goes alone. Here you are "lucky" to fly into such a hole that the wheel is ejected. But will a replacement help with a new one? Not always. It is possible (even normal!) That other knots affected by the blow will have to be repaired. For example, a deformed hub, steering knuckle and bearing.
But the pit is an everyday matter. No one is safe from this disaster in our country. It’s much more offensive to someone whose car was crippled during a “repair” in a car service, but not for free.
Recently, a cheerful guy at the Nine arrived to us. And very brave. You can judge this by his story. I traveled a long time ago, hearing a rumble coming from the front wheels. Friends warned: change, they say, bearings, otherwise, God forbid, they will jam on the go …
Realizing what he was risking, the brave daredevil continued to drive - business! When the buzz began to interfere with communication with fellow travelers, he finally went to the service. They liked the magicians there: funny, grimy - they did everything in two, in the presence of a smoking customer. Spent an hour and a half to replace two bearings. I, did not believe the storyteller: so, "in a Stakhanovian way", my masters cannot work! But when the owner described the "advanced technology", he realized that the guy was not lying, the benefit was the results of hard work - here it is, "nine" with a steering wheel shaking on the go, waiting for a diagnosis!
It turned out that the rationalizers simplified the technology of replacing bearings. They do this without removing the struts or knuckles, without using the press. Why is it all when a good sledgehammer is in hand! Having disconnected the drive and the ball bearing, they turn the steering knuckle to the side and, having removed the snap rings, hit the bearing! One supports the fist, the other beats. The performance is breathtaking.
New bearings? Also a sledgehammer! That's how our hero, leaving the craftsmen 900 rubles., And left. At first, she was just happy: the hum was gone! But later he began to notice new, unpleasant features in the behavior of the car: on the move, the steering wheel vibrated at different speeds, but most of all - with every attempt to brake, although the brakes themselves became "inaudible".
A smart little rebalanced wheel. To his great chagrin, this did not get better. Here with this riddle and arrived.
I do not believe in miracles. If the brakes shake after replacing the front bearings, it means something with the discs. It is from this “stove” that we will begin our dance: we will put a fixture and measure the beat of the disks. The operation is commonplace. Made. The result was stunned: the left disk showed a runout of as much as 1.13 mm! Right - 0.4 mm.
After removing the discs, measured the beating of the hubs. Given the difference in radii, the picture was proportional: the “curves” of the hub set the law for the behavior of the disks, and with them the wheels. Here are the sources of vibration.
Well, what was the root cause? Impact-sledgehammer approach to such delicate work as replacing bearings. The latter (I’m not ashamed to repeat it!) Are very gentle: the outer ring, set into the deformed socket of the knuckle, will easily take the corresponding shape, the inner rings will also easily stretch over the curved hub. And the sledgehammer is an effective tool: one indiscriminate blow is enough for the deformation, invisible to the eye, to “fly out” far beyond the tolerances!
But that is not all. If the bearing is skewed when pressing in, it also crushes the softer metal of the socket, and even removes the chips. That is why we are doing this work with utmost attention to all the “nuances” - and only in the press.
But how to help the client? We measured bearing seats. Slewing fists are tolerated. (He was lucky!) The beating of the hubs was measured on a lathe. They are beyond. To the ejection! The picture is clear, now you can collect. Pressed new bearings and hubs, and then checked the beating of the hubs already in the bearings. Not more than 0.03 mm - normal. Rotate 180 °, which often helps, did not have to. It remains to wish the client a fair wind.
By the way, conventional technology involves removing the knuckle assembly from the strut assembly with the hub. But the fist fixing bolts are sometimes difficult to unscrew; moreover, the vanishing and camber adjustment completes this work. We remove the entire rack assembly. The complexity is not much greater (1.22 normal hours instead of 1 hour), but the customer will only benefit by saving on the collapse.
This is such an interesting case, right? But I would like to have fewer!