2003 DGC Sport, 3.8L 216k - Steering requires major strength to turn the wheel to the left coming out of my driveway first thing in the morning. Turning the wheel right requires only normal effort. Once running down the road, the issue has only reappeared once in the month or so it's been happening.
When I first noticed I could not turn the wheel to the left in the morning I was braking to enter the street. Letting off the brake and turning the wheel back and forth sometimes freed it up. There was always a clunk when the steering broke free. Bouncing the steering wheel right/left/right/left slightly a few times sometimes got it to release as well. This morning I noticed the wheel didn't want to turn left when moving backwards as well.
I have checked for low fluid level (no), tie rod binding (no), loose stabilizer links (no), loose ball joints (no). It seems to be coming down to something in the rack, but I replaced it 3 years (~60k) ago, shortly after I replaced the struts and stabilizer links. I did have to replace one of the strut bearings (groaning on turns) a year ago, and occasionally I hear the same sound again now, but not continuously as it was before. I have replaced the P/S reservoir once, and a year later poked holes in the screen to stop the pump cavitating when cold. I replaced the sway bar bushings after this issue started, which stopped the clunking on bumps, but it did nothing for the morning "No Left Turn" issue. I didn't not notice any looseness at the ends of the sway bar. I have NOT checked for a loose mounting bolt on the rack, which might be the source of the clunk when the steering frees up, nor for a loose strut/steering knuckle bolt, since the alignment seems to be fine..
This morning I revved the engine in neutral when the steering bound up in reverse, and found I could turn the wheel left. Not sure if that was a coincidence, because it didn't stop the binding up when entering the street and trying to go left. Fortunately, there's hardly ever traffic on my residential street, so I can do a parallel parking maneuver to go straight down the road, after which I don't have a problem turning left. Does the clunk I usually hear when the steering frees up suggest anything to anyone?
I have tech friends at a couple of Mopar dealerships, and none have seen this issue before. Ring a bell with anyone here?
I don't want to replace the strut bearings since that entails an alignment which I cannot do myself, but that's where I'm looking now. I doubt there's a rack issue, because it only binds in one direction, only occasionally, and there are no leaks. I'm also thinking of flushing the P/S system with fresh fluid, in case there might be a metal fragment that got thru the little hole in the screen and is lodged in the valve body of the rack.
Anyone have any suggestions?

Bill

 

The clunk is a strong indicator that it's a mechanical problem, not a hydraulic one. However, to be thorough, a possible restriction in the hydraulic system can't be overlooked.

To check for restriction in the hydraulic system:

Jack up the front end and support it so that the wheels clear the ground but the control arms hang freely - try to minimize the ground clearance as you want the vehicle as level as possible. Center the steering wheel. Without touching or holding the steering wheel, start the van - does the wheel turn on its own? If not, rev the engine to 2000 RPM - does it turn on its own now? I don't mean a slight turn left or right - that would be normal - I mean the wheel is clearly turning on its own for at least 1/2 turn or more.

If it's turning on its own, there is a restriction in the hydraulic system (most likely the rack). However, it's not likely you'll be able to flush it out - you can try, but if this has been an issue for some time, the restriction is such that normal operating pressures will not flush it out which means the only solution will be to either replace the rack (recommended) or disassemble it and clean it.

If the hydraulic system tests OK, the problem is isolated to one of 3 mechanical areas:

1) Related suspension and drive train components (struts, ball joints, wheel bearings, CV axle, lower control arm)
2) Rack (internal components, inner and outer tie rods)
3) Steering column

Keeping the wheels off the ground, engine off (if you have a steering lock, turn the key to run position without starting the engine to release it), turn the wheel stop to stop.

Does the clunk still happen?
No - problem is isolated to related suspension and drive train components.
Yes - proceed to next step.

Center the steering wheel. Remove the front wheels and disconnect the outer tie rods from the steering knuckles. Turn the wheel stop to stop (you may have to use bungee cords or some other rigging to make sure the tie rods will not catch or drag on the cradle or control arms - an assistant may be useful for this).

Does the clunk still happen?
No - Problem is isolated to related suspension and drive train components.
Yes - Proceed to next step.

Center the steering wheel. Disconnect the steering column from the rack and make sure it can't catch or drag on anything - again, an assistant would be useful here. Turn the steering wheel NO MORE than 2 full turns in either direction. BE CAREFUL - there will not be stops with the column disconnected and rotating the wheel too far in either direction can damage the clock spring in the steering wheel. In fact, you should probably disconnect the negative battery cable for this step to prevent accidental discharge of the air bag.

Does the clunk still happen?
No - Problem is isolated to the rack.
Yes - Problem is isolated to the steering column.

Good luck.

 

Thank you Gumby, good information there.

The new reservoir was delivered today, and since I haven't had the resistance to turning left in about a week now, I'm going to R&R the PS reservoir and flush the system with new fluid. Someone local suggested I reverse flush it with air pressure behind the fluid, so I may try that too. Are there any check valves that would keep a reverse flush from happening?

Any idea what the PS fluid capacity is for a complete system fill? Again, it's a 2003 Grand Caravan 3.8L FWD, which the manual says takes ATF+4 in the PS system.

I will have to replace the left strut bearing before long, it's groaning when the wheel is turned like the right side one did about a year ago. When I replaced the right bearing, it looked like several ball bearings were missing. Could there be a binding left strut bearing issue that would cause the occasional restriction in turning left first thing in the morning, and cause a clunk when the bearing freed up?

Job #1: get a new reservoir and new fluid installed, see what difference that makes, if any.
Job #2: go through the diagnostic steps you outlined.

I'll update the thread with the results.

Thanks again.