After Lomonosov had already had two different diesel locomotives with electric power transmission built, he also wanted to have a third locomotive built with a different type of power transmission for comparison. The hydrostatic transmission that was actually planned was not yet ready for use. The result was the first and to this day the only large diesel locomotive in history with a mechanical gearbox. It went into operation as Ю^m005 (Yu^m005) and was renamed Э^мх3 (Ye ^mkh3).

The chassis consisted of five axles driven by coupling rods and a one-axle and two-axle bogie at each end. The engine came from MAN and was the same as in the Э^эл2. Here, however, it was designed to be reversible, since the transmission did not have a reverse gear. It had three gears that were shifted via a magnetically operated friction clutch.

Although the locomotive achieved a very high level of efficiency of just over 30 percent, the power transmission was not without problems. In addition to jerky loads on the clutches, there were also broken gear wheels. Engine power was soon reduced from 1,200 to 1,050 hp. But even this did not solve the problems, so that the locomotive was soon decommissioned and the diesel-electric competitors prevailed.