Q: Overdrive Light comes on after 30 mph

Hello. It is possible that your Overdrive Light is coming on because your Third gear is bad. When there is a problem with the passing gear in your transmission, the overdrive light will come on. Therefore, if your passing gear is the Third gear, then yes, it could be causing the light to come on. The transmission will need to be either rebuilt, or replaced, to fix the problem. If the upper control arm is bad, it just needs to be replaced. The metal peeking on the strut is due to oil from the strut leaking on the metal part of the strut. This is an indication that the strut needs to be replaced. These issues should be diagnosed and repaired by a certified technician, like one from YourMechanic, an include an inspection of your suspension system.