My 95 tester is starting to make noise.

Check and lubricate the power screw and bearing between the pillow block and driven gear. Fina Marson Liplex ET NLGI #2 is the preferred lubricant. At the tester turn off the power and disconnect the power cord. Remove and inspect the motor brushes. The brushes are located at the bottom of the motor under plastic screw caps. It requires a flat blade screwdriver. Make sure the carbon brushes are equal length. Often removing and reinserting the brushes cures noise problems.