In automobile maintenance, for the parts that are difficult to disassemble or reassemble, and there is no or inconvenient to use special tools for disassembly and assembly, as long as the method is appropriate, the process is reasonable, and the word "skillful" is grasped, it can not only damage the parts, but also disassemble and assemble smoothly. The following small series introduces several simple and practical disassembly methods.
Removal of steering wheel
The steering wheel is firmly fixed and the disassembly method is improper, which is not only time-consuming and laborious, but also easy to damage the steering wheel. In this regard, hold the steering wheel with your left hand and pull it up with force, and tap the formwork beam (wrap some soft objects in advance to prevent damage to the outer surface of the steering wheel) at 180 (i.e. the corresponding department of your left hand) of the steering wheel with your right hand. Generally, it takes only a few times to remove the lower steering wheel smoothly.
Remove the outer race of transmission bearing
After the front bearing of the first shaft of the transmission is broken, the outer race of the bearing left in the bearing hole at the tail end of the crankshaft is removed by gas cutting, which is not only laborious and time-consuming, but also easy to damage the bearing hole. A better method is to find a waste valve. If the valve head is too large, it can be ground on the grinder (a small part should be left) until it can enter the inner hole of the bearing. Align the edge of the valve head (where there is no grinding) to the inner side of the bearing outer ring, and knock the valve stem laterally with a hand hammer to push out the bearing outer ring.
Remove the valve seat ring
One is the welding method, which is suitable for cast iron cylinder head (when there is no puller). Take a waste valve and process its head to make its diameter slightly smaller than the size of the valve seat ring. Place the valve stem in the valve guide and spot weld the valve and seat ring by one turn with electric welding. At this time, the cold shrinkage force after spot welding shrinks the valve seat ring. As long as the tail end of the valve stem is knocked with a hammer, the valve seat will come out. The second is heating method, which is suitable for aluminum alloy cylinder head. Put the cylinder head into the basin, add waste engine oil, take it out quickly when heated to boiling, and the seat ring will come out with a slight vibration. If it is difficult to get out, you can pry it with a screwdriver to get out smoothly.
Insert valve seat ring
After the preparation of valve insert (the interference and roughness shall meet the requirements, and the cold shrink valve seat ring or thermal expansion seat ring bearing hole, etc.) is completed, quickly place the valve seat ring flat on the valve seat bearing hole, insert the exhaust valve of the vehicle into the valve guide, and knock the valve head with a hammer. In this way, the valve stem can play a guiding role in the valve guide, the contact between the valve head and the valve seat ring is uniform and reliable, and the smooth insertion of the seat ring is ensured.