QuestionQUESTION: Hi Tim, I own a 2002 Ford F 150 XLT. SuperCab with short rear bed. It has about 88,000 miles. 4.6 engine. 2wd. I have had a vibration to the rear for several years. I am trying to finally fix this annoying problem. The vibration is felt in the seat. during the speed of 38-42mph and returns worse at highway speeds of 55 and greater. The vibration seems rotational. It increases with speed. Unchanged with the truck in drive or coasting. I have replaced with new tires and roadforce balanced. replaced rear rotors, released the rear parking brake. I had the driveshaft balanced, it didn't seem right when replaced and returned to be balanced again. Several more weights were added. There is no change to this annoying problem. The rear is tight with no leaks from axles or pinion seal. I am thinking that a dial indicator may be my next tool to purchase?
Any thought where to go next to repair? Also it has the single aluminum drive shaft.
Thanks in advance,
John
ANSWER: hello,
i am unable ta access common failures right now, but i would be curious if you can get the vibration to occur with the rear wheels raised. It could be a torque convertor (rare) vibration, transmission or , more commonly, the support bearing for the driveshaft (if applicable)
get back to me.
---------- FOLLOW-UP ----------
QUESTION: I had the chance to raise the rear wheels today. The vibration was very slight at the 40mph and much worse at over 60mph. This truck has the single aluminum driveshaft no support bearing.
AnswerHi,
If it is supported safely, and with someone at the ready on the brake, you can apply a stethescope to the shaft ends, and axle ends to determine the source.
A reputable driveline shop (Axle/ differential/ driveshaft rebuilder) should be capable of determining source.
There is also, an electronic ear tool, that allows remote microphones to be clamped to various componenents to isolate the source. A good repair shop will have this as well.
