Mercedes-Benz 722.8

Transmission general data

The 722.8 transmission (CVT) has been produced since 2005 and mainly used on Mercedes А170. It is also installed on other cars of А series with engine capacity from 1.5 to 2.0 liters.

The design of this CVT is based on model patent CVT with the "push" belt produced by Bosch-Fondorn and the most expensive spare part – the belt itself. This CVT is the analog and competitor of a Japanese CVT JF011E.

Technical issues and repair guidelines

Overhauls of old cars with this transmission usually require the kit of spare parts (gaskets and seals from Autoline) and the kit of friction components. Friction components are replaced quite often in the process of the transmission reassembly, because the 722.8 unit is removed together with the engine, and easily wornout frictions already have a negative impact on the clutch. Driving with worn rings and seals lead to oil starvation and premature burning of quite durable friction components.

The fluid in 722.8 should be changed timely together with filter. The fluid and its purity are critical for cones and belts of this CVT, therefore for old 722.8 units, it is recommended to add the fluid at every opportunity and check its level with a service gauge.

The electrical part always causes a lot of problems in Mercedes transmissions. The board was made by the partnering company of Mercedes and after the warranty period you can face such problems as contaminated fluid (metal dust) and overheating. Steel dust magnetized on sensors lead to their failure.The belt is another vulnerable place in this advanced unit. Mercedes used the belt with additional resource on durability and reliability for its CVT.

Shaft bearings are the first among hard parts to get out of order (like with Jatco CVTs) because of lateral dynamic loads. The end of shaft-cones service life means the end for the CVT unit itself. The lifespan of bearings is highly dependent on the fluid cleanness, and most importantly - on its operating temperature.