Zhang Gong and Wang Gong are both automotive engineers, and of course they look down on Li Weidong, a young car mechanic.

Even Wei Bin opened his mouth to persuade: "Xiao Li, this problem of getting out of gear is actually very complicated, the engineers of our factory have studied it for a day and a night, but they still haven't found out the cause of the failure." ”

However, Li Weidong also despised Zhang Gong and Wang Gong in his heart, both of whom were in their thirties, judging from this age, they should be "workers, peasants and soldiers college students".

The state abolished the college entrance examination from 1966 until it was restored in 1978, during which the 12 college students recruited were all workers, peasants and soldiers.

The enrollment of workers, peasants, and soldiers college students is based only on their background, not on their educational level, and those from poor and middle peasant backgrounds are given priority in admission, and many of them can even make mistakes in arithmetic problems in elementary school, and going to university is like coming to a literacy class.

Among the group of workers, peasants and soldiers, many outstanding talents have also been born, but they are individual elites after all. The overall level of workers, peasants, and soldiers college students is indeed a big difference compared with the source of students recruited through the college entrance examination.

Faced with Zhang Gong and Wang Gong's doubts, Li Weidong decided to show his hand, so he pointed to the gearbox of the faulty car and said: "The gearbox of this car should be imitated from foreign countries, right?"

"You guessed it. Wang Gong nodded, and then said: "There are still many differences between foreign gearboxes and domestic gearboxes at the design level, and it is not uncommon to see that this is an imitation of foreign gearboxes." ”

Li Weidong did not refute, but continued: "It's a copy of the ZF gearbox in West Germany, right?"

"Do you still know ZF?" Wang Gong showed a look of surprise on his face. He didn't expect Li Weidong to be able to speak about ZF, which is not at all the knowledge that an auto mechanic should have.

When it comes to gearboxes, Li Weidong's first thought is, of course, ZF, Volkswagen, Mercedes-Benz, BMW, etc., all of which use ZF gearboxes. In the future, there will be many domestic independent brands, which will also use ZF gearboxes.

Reminiscent of the Yellow River JN162 heavy truck, absorbing the technology of Austrian Steyr, and Steyr uses a German gearbox, then it is not difficult to guess that the Yellow River JN162 is actually an imitation of ZF's gearbox.

In the future, it is not uncommon to know that ZF gearboxes are the world's top 500 companies and the top suppliers of core automotive components.

But in '84, China was still relatively closed, most people didn't know about foreign countries, ordinary people couldn't even name a foreign brand, and it was impossible for auto mechanics to know ZF's gearboxes, and they had to be professional automotive engineers to know this kind of information.

When Li Weidong said ZF, Zhang Gong and Wang Gong immediately put away the arrogance in their hearts and no longer dared to underestimate Li Weidong.

"How do you know that we are copying a ZF gearbox?" asked Zhang Gong.

"If I can't even see this, how can I find the cause of the out-of-gear failure?" Li Weidong replied with a smile.

"Okay, tell me, why does this car automatically go out of gear? Is it a problem with the gear bushing?" asked Wang Gong.

Li Weidong shook his head: "Of course it's not a problem with gear bushings. ”

Wang Gong's face darkened, while Zhang Gong became excited: "Haha, I just said it, it's a problem with the speed gauge." ”

Li Weidong still shook his head: "It's not a problem with the speed gauge." ”

Zhang Gong's face was also dark.

Seeing that Wang Gong and Zhang Gong were going to join forces to scold Li Weidong, Li Weidong took the lead in picking up the tools, walked to the side of the faulty car, and removed a part from the gearbox after three clicks and five divisions.

Li Weidong showed this part to everyone, and at the same time said: "The reason for the automatic disconnection of the fourth gear is this." ”

"Is this a self-locking spring?" Wei Bin instantly recognized the part.

"Yes, it's a four-speed self-locking spring. Li Weidong handed the part to Wei Bin's hand.

Self-locking springs are not a difficult part to machine, many manufacturers can make them, and in the whole transmission, compared to gears and gears, it is not an important part.

Wei Bin took the self-locking spring, looked at it carefully, checked it again, and then said: "Xiao Li, I'm afraid you have made a mistake in judgment, this spring is not broken." ”

"I thought you had some high opinions! Do you hear it? This spring is good, not broken!" Wang Gong said mockingly.

Li Weidong pointed to the self-locking spring and explained: "This spring is not broken, but it is soft! It is precisely because this self-locking spring is too soft that it will cause the vehicle to automatically disengage in fourth gear."

After thinking for a few seconds, Wei Bin said: "The situation he said is indeed possible, the self-locking spring is too soft, which will lead to automatic dismounting. ”

Li Weidong then asked: "The batch of faulty vehicles that Yankuang repaired should have undergone three-level maintenance not long ago, right?

Wei Bin nodded: "The car on the coal mine has a lot of wear and tear, and their three-level maintenance will clean the gearbox." ”

"That's the problem, originally the self-locking spring was tightened, but when the gearbox was cleaned, the gears and gears needed to be removed, and the self-locking spring was released. The material process of this spring should not be up to standard, and if it is loosened suddenly, the tension will exceed the standard, and it will naturally become soft. Li Weidong opened his mouth to explain.

"Nonsense, the self-locking springs we use are all first-class products!"

"Zhang Gong, I don't deny your statement, if you put it in China, this spring is likely to be of first-class quality, but can it meet the standards of West Germany? Don't forget, what you are copying now is a West German gearbox!" Li Weidong responded.

"Then how do you know that there is a problem with the self-locking spring?" Zhang Gong asked again.

"In fact, when I saw that the gearbox was a copy of the German gearbox, I had already guessed that it was probably because the material and workmanship of the parts were not up to standard. And the gears, gear bushings, and gears have all been replaced, so most likely, it should be a self-locking spring. Li Weidong replied.

"Then how do you prove that the disgear is because of the self-locking spring?" Wang Gong asked a very stupid question.

Li Weidong looked at Wang Gong helplessly, and then said: "You have to prove this, you take this self-locking spring, go to the laboratory to test it, and then compare it with Steyr's data, won't you know the truth!"

The self-locking spring is just an inconspicuous small part, and before that, the engineers at the Yellow River plant also checked the self-locking spring in gear, but the spring was not damaged, so they didn't think about the spring becoming softer.

And in the engine, the self-locking spring is not a component that is prone to failure, even if the transmission gear is worn out, the self-locking spring will still be very strong.

However, the engineers of the Yellow River plant ignored one thing, the gearbox used in the Yellow River JN162 is an imitation of the German ZF gearbox, so the parts standard in the gearbox should also reach the German level.

The same domestic self-locking spring is no problem in the domestic gearbox, but in the German-designed gearbox, the material process is not up to standard.

Although the Yellow River Plant copied the German gearbox, it could not imitate the advanced German material technology.

Even if it is a complete copy of the German design, using domestic materials to piece together a gearbox, the appearance looks similar, but the service life and failure rate are very different.

For an experienced automotive engineer like Wei Bin, he certainly knows the importance of material technology. Before that, he had been thinking about whether there was a problem with the design, and as soon as Li Weidong reminded him, Wei Bin immediately thought that it might be that the material process was not up to standard.

This is actually a layer of window paper, which will break when you poke it.

After thinking about this, Wei Bin said: "Xiao Li, you go to my office to sit for a while, and I will go to the laboratory to test the elasticity and tension of this spring." ”

After Wei Bin finished speaking, he took the spring, took Zhang Gong and Wang Gong, and ran towards the laboratory without looking back.

......

Although Li Weidong can repair cars, he can't see at a glance that the gear is out because the self-locking spring is too soft.

The reason why Li Weidong dared to make such a judgment was because in his previous life, Li Weidong repaired the Yellow River JN162 heavy truck.

In 1986, Qinghe Transportation Company finally introduced 10 Yellow River JN162 heavy trucks, along with a booklet called "Yellow River JN162 Heavy Truck Repair Manual", which is Li Weidong's killer feature.

This repair manual introduces the possible faults of the Yellow River JN162, as well as the maintenance method, as long as the repairman is holding this manual, he can prescribe the right medicine to repair the car.

The reason why there is such a thing as a repair manual with the car is mainly because there are a lot of small problems with the Yellow River JN162. After all, it is a domestic heavy truck, and the technology is much worse than that of imported heavy trucks, and it is normal to have many small problems.

For this reason, the Yellow River Plant had to compile a special repair manual, and whoever bought the car would send a repair manual, which could be regarded as providing after-sales service.

For car mechanics, this repair manual greatly simplifies the workflow and reduces the workload. In addition, many of the faults described in the repair manual can also be applied to other vehicles. It can be said that the auto repair manual is equivalent to a simplified version of the auto repair textbook.

At that time, Li Weidong was still working as an auto mechanic, because of the needs of his work, he memorized the contents of the repair manual, but after such a long time, he couldn't remember what was written in it.

When Li Weidong heard the argument between Zhang Gong and Wang Gong and saw the faulty vehicle, he recalled the cause of the failure recorded in the repair manual.

As for Li Weidong, he guessed that the process was not up to standard, which was completely an explanation with hindsight. Faced with a known result, it is easy to put on a reasonable explanation.

......

Wei Bin hurriedly walked into the laboratory.

"Wei Gong, you stayed up all night yesterday, let's sleep and come back!" said an engineer.

"I'm not sleepy yet. Wei Bin took out the spring, and then said: "This is just removed from the faulty car, the four-speed self-locking spring, hurry up and test it." ”

The engineer took the spring and turned around to take it for testing, but Wei Bin added: "Size, horizontal measurement, vertical measurement, etc., are all omitted, and the physical performance test is directly carried out." Zhang Gong, you go with you, and give me the data after the test. ”

Zhang Gong nodded and followed.

Wei Bin instructed again: "Wang Gong, you go to the data room, find out the data of the self-locking spring of the Steyr gearbox, and we will compare it later." ”

Wang Gong agreed, turned around and walked to the data room.

After a while, after the test was completed, the results were clear at a glance when the two points of data were compared.

"It's really a problem with this self-locking spring!" Wei Bin muttered to himself.

Zhang Gong and Wang Gong looked embarrassed.

"I was really right by the auto mechanic!"