1. Remove the plastic protective bottom plate under the engine first; 2. After removing the protective plate, expose the generator belt and lubricating oil filter, and then remove the exposed generator belt; 3. After the belt is removed from the bottom, remove the engine crankshaft output wheel next to the oil filter, and the removed output wheel; 4. Remove the expansion tank; 5, began to loosen the bolt of the main fixed bracket; 6. Remove the timing belt protective cover. After the rear cover is removed, the timing gear and brown toothed timing belt are exposed and can be directly replaced with new ones. Timing belt is an important part of engine valve system. It is connected with the crankshaft and matched with a certain transmission ratio to ensure the accuracy of intake and exhaust time.

Yutong Bus, as the core business of the Group, is the leading enterprise in China bus industry and the first listed company in the industry (SH.600066). It integrates the R&D, manufacturing and sales of bus products, and the products mainly serve the market segments such as public transport, passenger transport, tourism, groups, school buses and special cars.

Zhengzhou yutong bus company. Ltd (hereinafter referred to as "Yutong Group") is headquartered in Zhengzhou, China. Yutong is a large commercial vehicle group with buses and trucks as the main products, covering buses, trucks, special vehicles, sanitation equipment, construction machinery and so on. Has two listed companies (Yutong Bus, SH.600066；; Yutong Heavy Industry Co., Ltd., SH.6008 17), 4 automobile plants and 5 parts bases. By the end of 20021,the cumulative sales volume of new energy commercial vehicles exceeded 1.6 million, making it the largest bus enterprise and new energy commercial vehicle enterprise in the world.