Driving home yesterday in the heat of Maryland, I finally broke out of traffic and got up to 55. After a couple of miles a _serious_ vibration started, shaking the entire truck- steering and brakes. Braking for a light was an adventure- I thought my teeth were going to fall out. The vibration continued almost until I stopped moving.
When the light turned, I cautiously accelerated to the gas station up ahead. To my amazement, the vibration was completely gone. I pulled in and checked the lug nuts and the tires. Nothing appeared to be wrong, lug nuts fine, no bulges in the tires. Shook the truck, didn't seem to be any hubs loose(!). Checked the power steering fluid, it's fine. Hmm! Gassed up and left.
A couple of miles down the road it happened again. I pushed the clutch in and hit the gas- the engine revved fine. Ok, it's not related to the engine. On the way home I could make the vibration return by varying speed. Note that this is not like an out of balance tire, I'd have to go a couple of miles at cruising speed before it would come back.
By the time I got home I had developed the hypothesis that one of my tires was deforming under sufficient heat/speed stress- basically a prelude to a blowout.
Now, the two rear tires are old and the fronts are new (2K miles), but the steering was so affected I'm thinking the problem is in the front end. RF tire has had a slow leak, so I pulled it off and found a nail in it. Nothing exceptional, though. I replaced it with the spare, and I guess I'll see if it happens again today. But my questions are:
Is this a reasonable conclusion? Even though the tires look normal when I examine them? Is there _anything_ else I should be looking at?
Thanks very, very much for any insight. This is doubly frustrating because 48 hours ago my other car developed a stuck caliper. Grrrrrr. It never rains... Jim