I have a 1999 Ford Ranger, 67,000 miles. 2 wheel drive, coil spring front suspension. I have a clunking noise that can only be heard only in warm/hot weather. The noise can be heard when the temperature is around 70 degrees and above. The longer I drive, the louder the noise gets. After about 30 minutes it is a loud clunking sound. In cool/cold weather, under 70 degrees, the clunking can’t be heard.
Here is a list of what I have done to date to try to remedy the problem:
I have replaced the front end upper and lower control arm bushings, stabilizer links and bushings, all four ball joints, tie rod ends, new front and rear shocks, four new tires, and a front end alignment. The engine and transmission mounts are in good condition and tight. The cab to frame mounts are in good condition and tight. The rear leaf spring and shackle bushings are all in good condition. I have checked the exhaust for knocking against the frame, all hangers and mounts good. I have checked the steering rack bolts and insulators. Doors and hood seem to fit well, no rubbing. I have checked the front wheel bearings for any play. The front and rear brakes are in good condition, brake shoes are good, calipers and brake cylinders are in good shape. Nothing in the brake system is loose. I tried riding the brakes; this did not get rid of knocking. I removed the outer tie rod ends and checked the inner tie rods for play by moving the outer tie rods. I have looked under the hood, looking for anything loose.
I have done some of the above work myself, and some was done at the Ford truck dealer. The Ford dealer was unable to locate the source of the noise.
One note I should mention. When it is 70+ degrees outside and I bounce up and down on the front bumper a rubbing, almost grinding noise can be heard coming from the front of the truck. But if I do the same bouncing on the front of the truck in weather under 70 degrees there is no rubbing/grinding noise at all.

 

[sm=welcomesign.gif][hr]It sounds like the radius arm bushing's

 

Thanks for the reply. My truck is a 2 wheel drive, does it have radius arms??

 

Yes and it's a common problem in ranger's

 

I'm not sure what you mean by the radius arms. Are these by chance what I call the upper and/or lower control arms? I had all those bushings replaced.

 

The radius arm's hold the ibeam(front axle) assembly straight.[hr]There long triangle looking and have the bushing's on the end under the floor pans.

 

Just so I have this correct. The radius arm bushings are located on the front I beam between the beam and the floor pan. These are not the same as the cab to frame bushings that are a round sandwich type mount found near the front of the frame. My truck has the coil spring front suspension by the way if that makes a difference.

 

no twin I-beams in '99

 

wheel bearing?

 

I think it may be the grease drying out in the inner tie rod knuckle were it connects to the rack gear. I pulled off the outer tie rods and spun the inner tie rods to loosen up the grease. I'll see if that helps.