How Do You Tell If Motor Mounts Are Bad?

[longball425]

I have replaced my tranny mount...obvious that it was worn out...car was shaking like mad.... but.....I still have a slight vibration at higher speeds...I have ruled out wheels/tires....I am not sure how to tell if motor mounts are worn out....

any ideas?

[dcfish]

I have replaced my tranny mount...obvious that it was worn out...car was shaking like mad.... but.....I still have a slight vibration at higher speeds...I have ruled out wheels/tires....I am not sure how to tell if motor mounts are worn out....

any ideas?

Open the hood and rev the motor, If it rocks back and forth replace the motor mounts. If the tranny mounts were shot then the motor mounts take a beating and should have been replaced at the time of the tranny mount.