Hi All,
I have a 99 F250 S.D. 4X4 and have an issue with the front suspension. First my truck has about 760,00 miles on her and it runs great. Now the issue is when I am driving it, like on city streets or highways, it rolls along nice and smooth. When on the highway at above 50 mph or so if I have to break hard it will start shaking pretty bad. Also I live up in the mountains here in Southern California and when going down the mountain on the steep grades if I hit the brakes hard it does the same thing in that it starts to shake really bad. So seeing how the truck has a high amount of mileage on it I recently started replacing components first was the complete steering linkage, all the components. That made no change. Then I went to new Moog hubs along with brand new rotors and brake pads and still no difference. Also it has brand new wheels and tires on it and I have rotated them and had them rebalanced a couple of times. The next item on the list is going to be upper and lower ball joints but before I do so I want to know on that Dana axle is there a proper way to test the ball joints to actually see if they are bad ??? I did a quick search on the net to see if there were any videos that had a run thru that showed the proper way to test them but everything I found related to upper and lower control arm type suspensions. My other question would be what else if anything would cause it to shake so much ?? Like I said I have replaced almost every component there is and I am at a loss now and would really like to get this figured out. Any suggestions or possible remedies would greatly be appreciated. Thanks

 

To test the front ball joints, lift either tire by the front axle, just enough to get the lifted side tire off the ground and inch or two. Using a bar under the tire lift up, there should be zero play. It's hard to see while doing it but if they're lose you could see it. And always you can put your hands at 12 o'clock and six o'clock simulating a similar thing and you'd feel the looseness or play in the ball joints... Use your muscles gripping the tire treads top and bottom and just try and wiggle / rock it top to bottom. left to right play indicates steering linkage. Shouldn't be there since you've replaced that already. I'm in Fontana, if you're in the I.E. just let me know, I can lend a hand if the shops you're using can't show you what's wrong before just replacing all those parts despite the high mileage