1990 Mitsubishi Eclipse Balance Shaft Belt Tensioner Replacement Cost

Diagnosis of a failed or failing tensioner requires removal of many components, and hands on inspection of the balance shaft belt tensioner. If the servicing technician finds the pulley is loose or damaged in any way, they will recommend immediate replacement of, at minimum, the balance shaft belt and balance shaft belt tensioner pulley.

At a minimum, replacement involves removal of the timing cover, balance shaft belt tensioner, balance shaft belt, and the balance shaft belt pulley. The balance shaft belt tensioner is typically attached by one bolt, but installation requires the proper amount of tension to be applied to the balance shaft belt and idler pulley retaining bolt. Once all components are replaced, the timing components can be installed onto the engine, and the engine will be tested for proper operation and balance shaft timing before additional components are replaced.

Since this service requires removal of the balance shaft belt and timing cover, it is recommended to replace the timing belt, water pump and possibly front seals at the same time, unless they have been recently serviced. This is much more cost effective than returning for the same service after a partial service interval has elapsed.

It may be necessary for the motor mounts to be removed from the vehicle, as well as engine cooling fans, the radiator, and all engine accessories. This may include components like the alternator, A/C compressor, mounting brackets, coolant or fuel lines, and any other component that interfere with access to the timing cover or front cover.

Since balance shaft belt tensioner replacement necessitates the removal of timing components, it is not recommended for the DIYer to attempt this task. A thorough knowledge of internal engine components, engine timing, accessory systems, and several specialty tools are required to properly perform this repair.