death wooble, tried everything...HELP?

[lofly'a]

i have a 2000 Silverado reg cab v6 with 123K. about a year ago i noticed shaking that got progressively worse as speeds increased. this was/is an intermittent problem that does not always happen. since then i have change all ball joints, inner and outer tie rods, shocks, tires, checked and rechecked balance, & rotated tires. i rarely drive the truck over 50mph and this only occurs over 50. i drove it to the pick and pull 2 days ago and thought i'd lose my teeth on the way there (about 5 miles). on the way back the ride was as smooth as and old Cadillac. By definition from what i understand that death bobble is the uncontrollable rapid back and forth motion of the front wheels at high speeds. This was confirmed by a passenger that was willing to hang out the window to observe this at speeds.

[truckdude239]

have you changed the pitman arm and the steering idler arm and bracket?

[lofly'a]

it has rack and pinion, so no as these dont apply here. the thing is, is this thing is tight and precise with no slop in the steering. i'm stumped.

[72afr]

Coming from the Jeep world and have experienced DW on my ZJ, typically it's on vehicles with a SFA. I can't say I've heard of the typical DW being used to describe something with IFS. Most of the scenarios I've seen have DW presenting when you hit a bump at speed, not when you reach a certain speed. I'm not discrediting you, just seems odd. Have you replaced the R&P? I'd again look at the tires. I thought my TJ had DW, but the tires were so bad that the whole thing would shake above 45. Swapped tires and everything corrected.

DW is a scary beast.

[hatzie]

Do the rack and pinion trucks have a steering damper?
I'd replace it if it has one.

[Boog]

A visit to an alignment shop is the next step after replacing all those front end parts. They might find something you didn't.