The first thing I thought of was the problem of dynamic balance of tires. When I went to the car repair shop to do dynamic balance, I found that each tire had a deviation of 10-20g, and more than one of them reached 30g. I thought that no wonder I shook, and when the dynamic balance was done, I felt comfortable. On the highway, the jitter is better, but it’s still the same symptom, just a little lighter. This is awkward, but the problem of tire dynamic balance is complicated. Because we usually move is to change the tire, other places are not very good at moving. That could be what’s wrong with the car.

Search for high-speed vibration on the Internet, some say that the engine resonates, some say that the resonance point of the car is in this speed range, some gearbox problems, some talk about foot glue problems, and some talk about four-wheel positioning problems. I saw the same situation as a car owner in the forum, and then I went to the Michelin store to make a dynamic balance. It is said that the dynamic balancing machines of ordinary shops are not correct. There is also a car owner who does a good job of tire and road dynamic balance. Last time the maintenance also let the master take a look at the chassis, there is no problem. The main thing is to lock the problem on the tires. Small place, not so sophisticated equipment. I can only find an experienced master and find a shop that specializes in selling Michelin tires to do dynamic balance. An old man came, and the old man asked what was wrong. I said the car was shaking at high speed, but he said that the dynamic balance was not well done. I said it wasn’t long before I made the dynamic balance. Let’s try again if it is because the dynamic balance is not done well. The old man firmly said that it must be a problem of dynamic balance, saying that he could rest assured that he would be fine if he had done dynamic balance. When the tires were taken off, the old man said while doing it that they were doing dynamic balance, messing around, and sticking balance blocks everywhere. On his machine, it shows that the tires that have just done dynamic balancing have a deviation of about 10-20g. Now I feel at ease, depending on the old man’s experience and determined attitude. Feel that the problem has finally been found, full of hope. There was an interlude. When the old man set up the car, the square foam was padded around to lift the car. As a result, the side guard under the doors on both sides was deformed, and one side of the top cracked. I said, what’s the matter with you? the old man said it wasn’t his problem. I was already cracked! Hey! Forget it, if you don’t talk to him, you won’t pay for it. Admit it! As long as he does that, the car will stop shaking. Finished, full of hope immediately went to run a few minutes of high-speed test! My ass! Still shaking! Don’t mention the mood at this time. The problem was not solved, and the car was backed up for me!

When running at high speed, I wonder if it will be a long time, the engine power is not as good as the new car, and the power does not match with the gear. But constant speed cruise 120th, rotational speed 2050, should be no problem, try it, high-speed constant speed cruise 120th, change S gear, still shake, manual downshift 6, speed more than 3000, still jitter, it seems that it is not caused by drag. Ready to give up, the highway is calculated by more than 130. Anyway, the points will be deducted only by 10% of the highway exceeding the speed limit by 20%. But I feel uncomfortable all the time.

Two days ago to maintain and change the oil, the chassis rose and carefully checked whether the lower chassis was loose and whether the rubber sleeve had cracks and aging. As a result of a long time, there is a lot of ash and mud on the chassis. Do not touch one by one, one by one to look carefully, at a glance is that there is no problem. Looking carefully one by one, I found that the rubber sleeve in the balance block above the rear axle differential had all cracked, the feeling that it was about to fall off, and the feeling that I had found the problem of jitter again. Since the manufacturer specially set up a balancing block in that position, it must be useful. Continue to check, found that the drive shaft and rear axle differential connection of the plastic disk is also cracked. And the rubber sleeve connected to the differential of the subframe is also a little cracked. Not to mention whether this is the cause of the jitter or not, the rubber disk of the transmission shaft alone feels almost broken, this one is not changed, it is broken at high speed, isn’t it Barbie Q? Decisive order, transmission shaft rubber sleeve? Differential balance block. To replace the rubber cover on the subframe, you need to remove the entire rear axle, and the crack is not too big, so don’t move that place for the time being.

I went early the next morning and said that the goods had arrived and were exchanged. Differential balance block is easy to change, change it down and weigh it, such a block, there must be 4jins! This gap is so large that it must have a greater impact than the 20g deviation of the tire. The connecting rubber plate of the transmission shaft needs to remove the heat insulation plate, and the fixed rubber sleeve in the middle part of the transmission shaft must be removed in order to replace it. After dismantling, I looked at the rubber disk of the gearbox connected to the transmission shaft. All right, there are no cracks, and the middle one is good. After the change, people are relieved. After running high speed, the jitter is gone, and the mood is relaxed! The hidden danger of safety has also been eliminated, happy! You can rest assured to open it boldly!

I hope it will be helpful to cyclists in a similar situation. I wish you all a safe and pleasant car.