I am new to this site so bare with me. I have a '95 F150 with a 302 and when I go down the road at a constanst speed, I get an intermittent vibration for about 3 seconds, calm for 3 seconds, vibration for 3 seconds etc... My initial feeling is to check the u-joints before I dig deeper. I am looking for some information.

Also, I am getting about 10mpg and most of my driving is highway miles. I just bought the vehicle and I was going to do the normal tune up things (plugs, wires, air filter & fuel filter). Is that anything else that I should look for?

 

Sorry, I won't bare with you. I'm keeping my clothes on.

I will bear with your question. I'll hold off on an answer until you do the tune up you have planned. Post again after that and I'll bet your problem is gone. It sounds like an ignition problem, but if that doesn't fix it you need a transmission fluid change. Worn out transmission fluid can do that, too.

If you do change the fluid, make sure all of it gets changed. The fluid in the pan is only about 1/3 of the total.

 

I had the same vibration problem with my 92 4x4, turned out to be the yoke that bolts to the pinion on the rear end was wore out, truck has almost 300,000 miles on it.

A performance tun up and premium gas gets me a lot better gas mileage too.