سایش زنجیر جعبه انتقال

Most transfer cases drive the second axle through a chain, and a chain stretches with miles and load. A stretched chain jumps teeth under torque — felt as a metallic slap and a momentary loss of drive under hard acceleration, and read by the control module as a ratio that does not match the range selected.

The pattern separates it from a shift that never completed: an incomplete range shift is wrong all the time, a stretched chain is wrong at the moments torque is applied. Replacement means opening the case — but catching it early keeps the shed metal out of the gearset and bearings, which is the difference between a chain and a rebuild.