Transmission and vehicle

The invention provides a transmission and a vehicle. The transmission comprises a shell, a bearing, a mounting opening and a retainer. A counter bore is formed in the shell, and a locating groove is formed in the hole wall of the counter bore. The bearing is arranged in the counter bore, a locking groove is formed in the peripheral side face of the outer ring of the bearing, and the locking grooveis opposite to the locating groove. The mounting opening is arranged on the sell and communicates with the locating groove. The retainer is arranged in the locking groove and the locating groove. Inthe mounting process, the retainer is arranged in the locating groove, and the retainer can be adjusted through the mounting opening so as to mount the retainer in the locking groove. The locating groove used for locating the retainer is arranged in the counter bore, a conventional bearing locating structure arranged on the outer side of the counter bore is omitted, and therefore the thickness ofthe shell in the bearing ax