![Surprised :o](./images/smilies/icon_e_surprised.gif)
Symptoms: SOMETIMES hitting a random kind of bump between 25mph and 40mph or so causes that wheel (and ONLY that wheel) AND the steering wheel to go into a NASTY sawing/shaking wobble... and the only way for it to go away is to let off the gas and let the truck decelerate down to about 15mph. Hitting the brakes makes it worse. It doesn't happen at any other speeds, hitting small or big bumps HARD at higher speeds is fine. The truck feels solid steering and suspension-wise at speed. Also, sometimes hitting the same bump at same speed doesn't cause it to wobble. I guess it just needs to hit bumps a certain way. It can happen to either wheel, but it's definitely happened more often on the left wheel. This occurs maybe once every 75 miles of around-town driving.
Current front-end setup: Fully heimed Southwest Performance standard width C&T beams and radius arms, Bilstein 9100 remote reservoir coil-overs with Southwest Performance fabricated towers and brace, and ambulance upgrade stock-type steering setup with a dropped pitman arm.
Things checked out: The ball joints, tie rod ends and all fasteners were checked and nothing checked is worn-out or loose. Also, I have TONS of caster.
Notable items:
1. The camber/caster alignment bushings do not seat all the way in - the taper on the upper ball joint's fills out the taper on the cam bushing BEFORE the cam bottoms out, about 1/4" of an inch. See the picture. I don't know why that is, and it's the same on both sides. I've tried different cams, same result. I'm guessing the spread between the ears on the beam were made closer from cutting and turning the beam?
2. My coil-overs don't have a lot of miles on them, but they are nearly eight years old and they've never been rebuilt, so I'm not sure if they've lost their nitrogen. It doesn't feel like the wheel is bouncing up and down when I'm getting the death wobble, but it's entirely possible.
Ideas?
Thanks
S