Nissan manual transmission makes strange noises when shifting to fifth gear.

The owner described that everything else was normal during driving, but when shifting to fifth gear, there was a rattling noise. After checking, it was indeed coming from the transmission. Later, the transmission was disassembled and it was found that all the gears were not worn, there were no teeth, and there was no problem with the bearings. This made him fall into deep thought. Later, all the gears of the fifth gear were disassembled and it was found that the shift gear could not be disassembled. After cleaning and checking carefully, it turned out that the internal teeth of the fifth gear were jumping, causing the gear to slip under force. I thought it could be disassembled, but the two gears of the fifth gear were compacted into one. The internal teeth are extremely small and cannot be seen without careful observation. Everything is normal after replacement.

Fault phenomenon Fault phenomenon