Replacing All Aveo Subframe Bushings (Front and Rear)
To replace all the Aveo front subframe bushings, you need to raise the front of the car and release several points:
1. The power steering fluid needs to be drained, as one of the hoses—the return line—is short when lowering the subframe and needs to be disconnected. We'll also change the oil and clean the expansion tank. Use a syringe to suck out the old oil from the expansion tank, unscrew one bolt and two nuts securing the expansion tank, remove the clamps from the two hoses that connect to the expansion tank, and, placing a bottle under the upper hose, begin turning the steering wheel left and right. The pump will force out any remaining oil from the line. You will need to fill the oil in the reverse order - connect the hoses, attach the tank, which has already been washed with gasoline and dried, then fill it with oil and turn the steering wheel. The line will start to fill - the level will drop - add oil, turn the steering wheel again and so on until the level stops dropping and all the air is released. 2. From the inside, disconnect the steering column from the steering rack. Before doing this, you need to lock the steering wheel in the lock by removing the key from the ignition and turning the steering wheel until it clicks. Otherwise, the steering wheel will start to spin freely, which can damage all the wires going to the airbag and horn. To do this, completely unscrew the lower driveshaft bolt and loosen the upper one. First, mark the driveshaft splines with paint so that the steering wheel fits properly during reassembly.
3. Unscrew the lower engine mount. It is attached with two bolts in the center of the subframe and one bolt to the engine. By unscrewing it, you will not only make your job easier, but also gain access to the subframe interior, allowing you to clean out any accumulated dirt and apply Movil. Next, you can unscrew the subframe in four places: the bolts on the rear bushings and the nuts on the front ones. 4. To replace the front subframe bushings, remove both control arms by unscrewing the ball joints and two bolts. It's best to combine these operations and replace the control arm bushings as well, and if necessary, the ball joints as well.
5. Support the subframe with a jack in the center so you can move it up and down smoothly and evenly. Unscrew the rear bushing bolts and the front bushing nuts. Lower the jack, and the subframe will easily separate from the body. Pay attention to the return hose, which is secured with a clamp and runs upward toward the battery; disconnect it from the steering rack.
6. The rear bushings are easy to replace. Insert any socket between the body and the subframe and apply pressure from underneath with a jack in the center of the bushing, either without a washer or using a smaller washer. The bushing comes out easily—remember how it was installed—which way is up and which is down. Lubricate the new bushing and its mounting surface with soap, and the area where it contacts the body with lithol or another lubricant, as the metal part of the bushing rests against the body; without lubrication, it will stick to the body. Place the new bushing, remove the head between the subframe and the body, and then apply pressure with the jack to the subframe. The bushing will easily slide into place.
7. To replace the front bushings, lower the subframe as much as possible. You don't need to remove the tie rods, and I probably don't need to remove the stabilizer bars either, but I was replacing them, so I removed them. Next, using a pipe and a long pin, begin to pull out the old bushing.
8. Inspect the old and new front bushings. It turns out they don't fit tightly, but with a lot of play. Considering there are no scratches or impacts on the body stud, this means the bushing doesn't experience horizontal impacts, only vertical ones. So, in theory, it doesn't need replacing. The old one looked very good, but since I've got it out, I'll replace it. We tighten the new bushing, after lubricating it and the seat with soap, using a short pipe.
Next, we reassemble everything in reverse, ensuring the steering rack splines are properly seated inside the car, connect the power steering hose, and tighten all the bolts and nuts.
I read an article that said that the rear subframe bushings are touching the body metal, causing a metallic clunking sound. I had the same problem when I drove the car for the first time after the repair. I was immediately upset and thought that I would have to disassemble everything and turn the silent blocks upside down as suggested in the article, but after driving over speed bumps, first on the left side, then on the right, I determined that the knocking was on the right side. I climbed into a hole and it turned out that I simply forgot to tighten the rear vertical bolt of the suspension arm; the nut was turning by hand. Therefore, after assembly, do a test drive, and then check the tightness of all connections.