Random Frontend Shake?

[ManxManiac]

1999 GMC Yukon SLT 2 wheel drive, new balanced tires, straight rims, all steering components OK, shocks OK, all front suspension parts OK... sometimes at varying speeds (25-60+ mph) steering wheel starts jerking left & right... sometimes if I make a slight turn of the steering wheel, left or right, it will stop shaking! Sometimes braking will cause it to start or on a rough road it seems to trigger it! Usually steering slightly left or right or left then right or vice versa it will stop shaking! I'm thinking maybe something wrong in steering box? It has 225,000 miles. Anyone ever experience this? Would appreciate any ideas or thoughts!

 

[ccapehartusarmyINF.(ret)]

have you had the alignment done sounds like you might have excessive toe in or toe out / \ \ /

 

[ManxManiac]

Alignment was checked & it was right on spec. Everything has been checked numerous times, except the steering box & I'm not sure exactly how to "check" it. I mentioned in my original post, that usually, slightly turning left or right would stop the shaking, however, I forgot to mention that sometimes it gets so bad nothing helps & I have to come to a complete stop, then take off again. I even put a pressure gauge inline of the power steering pump pressure hose/line & it was within spec too.
This whole shaking thing started one day when I took a freeway off-ramp & has been random since then. I have driven 200 miles without an incident, yet several times I've only driven a few miles & it happens.

 

[ccapehartusarmyINF.(ret)]

there is an earlier thread that explains how to tighten the rack and pinion steering maybe start there

 

[ManxManiac]

It isn't rack & pinion, just a regular steering box.

 

[markman9118]

Having the same problem. Ever figure it out?

 

[cooper30]

I had a random, slight shaking in my '98 Tahoe 4x4. Turned out that the control arm bushings were worn badly.

 

[mizzouguy]

Friend of mine has a similar issue. Randomly at 55+ it would start to shake so bad they had to pull over and start again. I rotated the tires front to back and issue went away, making me confident that they had a bad tire.

 

[ccapehartusarmyINF.(ret)]

there is an earlier thread that explains how to tighten the rack and pinion steering maybe start there

my bad i meant steering box