Front knocking at low speed


#1

I have a 1999 GMC Sierra. I have been having a knocking sound that happens only at low speeds. I went to a mechanic, who told me that I had bad hub on both front sides. I replaced that (tough job to get that rusted thing off…), and I also replaced the rotors and the break pads.

Things were fine at first, but then the knocking returned. It happens only at low speed, and the lower the speed, the louder it is. It disappears once I get above 15MPH or so. It seems to be coming from front driver side. Turning or going straight seems to make no difference, but at times seems to worse when turning. Sounds like metal banging on metal, and just “knock, knock, knock” or a clinck, loud. It seems to be worse when the car is warmed up. I have taken that wheel apart since, but can not find anything obvious, or anything wrong with my job. All the nuts are tight, and connections intact. I cleaned all the parts extensively as well. There doesn’t seem a vibration with it, and nothing gets transmitted through the steering column.

Currently I am stumped, and can’t figure out if it is the rods, the CV joint, axle, bushings, etc. Did I knock something loose trying to get that hub out? Any ideas would be much apreciated!


#2

I think you need to get it off the ground or get somebody to assist and listen while you turn the wheels. Other thing is it maybe tranny related… take a good look at the motor mounts. broken springs, too. (brother had a 1998 and eventually replaced everything on the steering except the power steering box. and did replace the motor mounts and control arm bushings, tie rods etc…everything.)


#3

Thank you, yes, I was about to put it up and turn the wheel to see if I can reproduce the noise. I am not sure how much of it is transmission or engine related, because its does not seem to correlated to the gear switch. It just happens at low speeds, and gradually disappears as the speed climbs…