Driveline vibration around 50 mph
What a month for truck issues.
My truck is a 99f250 7.3, 4x4 auto.
My truck in the last few weeks has developed a driveline issue. It starts hard, won't start if not plugged in, is very sluggish when cold and the tranny is not wanting to shift at times. I have developed an intermittent vibration that comes and goes. It feels very much like driveshaft vibration but the driveshafts feel fine with NO slop in them. Almost concerns me there is no slop at all. I haven't got anything else that doesn't give a little. The driveshaft carrier bearing has some movement up and down but I was told at the dealership that was normal.
Same dealership has come to the conclusion that my injectors are bad via a buzz test. Recommending replacing them. At 290,000 miles I don't doubt it but I am concerned about the driveline vibes. There doesn't seem to be any play anywhere.
The vibration is in the seat, not the steering wheel and there is a bit of rotational noise accompanying it that is to the rear. It really feels like a driveshaft. Ia am transmission paranoid because I still have the original but the dealership seemed to think the not shifting is due to a power issue and there is definitely less power than in the past.
Any assistance would be appreciated. Facing the injectors, I am concerned about money, but I have to get the touch reliable.