Headscratcher: steering wheel vibration

[betsy325e]

Hello all,

Have a confusing one:

At low speeds or no speed (parked, foot off the brake)...turning the steering wheel left or right creates a crazy shimmy/vibration. There isn't any more or less resistance in the wheel...it's just this crazy shimmy. You can physically see the tire shimmying when it does it in the steering wheel.

Power steering fluid is right on the mark, not seeing any air bubbles pop in the reservoir as i go from lock to lock, pump isn't making any noise, not seeing any obvious play in the ball joints/tie rods, etc etc etc.

I'm leaning towards something's up with the power steering pump or something in the rack itself is frigged...but only because I have no clue haha

Looks something like what's up with this prius (just not as crazy): https://www.youtube.com/watch?v=3vLwX8nBL88


Anyone even heard of something like this? Any troubleshooting ideas?

Thanks.

[TobyB]

I suspect your rack,then the pump. Sounds like the valve in the rack's going.

t

[betsy325e]

Thanks. I'm a total novice on rack and pinion. I understand how it works in theory...but I've never put one in/had one apart just to take a peek.

If it were a valve in the rack that is going...how can i narrow it down to the valve in the rack for sure instead of the pump being on its way out?

I was hoping I'd be able to isolate the mechanical rack and pinion gear stuff from the hydraulic pump stuff to try to figure this out...hydraulic valves in the rack complicate that haha

thanks again

[betsy325e]

in the event someone someday googles this:

serious binding on a shot strut mount under load was causing the issue. wasn't readily apparent with the wheels in the air/and the mount itself didn't sound/look effed up...but it was binding like crazy under load...got that sorted and everything is fine again.

[exhaust]

How did you figure out that that was the problem?

[betsy325e]

process of elimination: i wanted to rule out binding on the struts -- disconnected tie rods and put the whole strut assembly under load using a jack while the car was on jackstands.

without jack pressure it seemed to spin ok, with a little pressure came some stiffness, with a little more came full on binding. not the case on the other side.

[TobyB]

Ha- excellent! Thanks for the follow- up!

t