My sons 2000 ranger started acting up this morning. he said when he tried to move forward it would have a bad vibration. I followed him as he went to school. But I could not see the wheels wobbling as if the lug nuts had come loose. I say this because just a couple of weeks ago we hadd to replace the brakes all the way around. someone had suggested to me the have a friend that had had issues with the tensioner pulley going out. Could a bad tensioner cause the engine to run rough and cause vibration? Because of the components not working properly? He said when he stopped at school it smelt a little like burning rubber (maybe the serpentine belt?). I'll check after I get off of work.

 

I'll guess either a stuck caliper or a rear shoe jamming in the drum. I'm leaning towards a stuck caliper against a warped rotor.
If the serpentine belt was hung up you would most likely get a check gauge light or alt light.

 

I think it turnsout to be in the tranny. Motor and brakes all working fine. He said all the gauges were reading properly. Tranny fluid was at the lower part of the grid was all. So filled it up. There still is a slight issue as you can feel it quiver a little under some acceleration but not all the time. What usually goes out on their trannies? Or should I post this question in a different section?