Hi:

2003 land rover discovery 2 with the 4.6L. 73K miles. Have some play in the steering box when returning from a right turn position back to the center position.
Feels like a slight clunk when it reaches this position in the rack. I'm not noticing this behaviour when the wheel is turned left and you turn it back to center.

I took the intermediate shaft off and checked both end U-joints. They are solid. cleaned them up good and re-lubed them. Re-installed.
This smoothed out turning nicely. Now just onto the slight clunk at 12:00 position. I verified that when returning to the 12:00 position
when the clunk occurs the the wheels are not moving until you get past this spot...meaning it's something amiss in the steering box.

Is the steering adjustment screw in the top of the box the next task now?

 

The steering adjustment screw will take up slack in the box...but I will caution you...make very small adjustments with it...LESS is definitely MORE when it comes to adjusting out the lash/slop in the box.

 

ya, that's what I read on the subject. I wonder what the cause of the bump when returning to center from either direction
would be caused by? if the gears were worn in that spot I wouldn't think it would manifest as a bump in the steering wheel.

would the sway bar bushings perhaps be the cause of it?

 

panhard bar, sway bar bushing don't really have any bearing on steering.

 

jacked the truck up with the wheels off the ground. no play in the tie rod ends on either side when trying to move the wheels in/out or up/down with a pry bar.

I do notice that when the wheel is turned to the right and you bring it back to center, the bump occurs just as you reach the centered position.
I'm not sensing this behaviour when the wheel is turned left and returned to center.

 

Sounds like it may be the steering box. I will second the comment about judicious tightening. 1/8th of a turn of the screw took out all my looseness. Does not take much.

 

the only thing that makes me second guess this adjustment is why it would only be occuring when I turn right and then return the steering
wheel position back to center. just as it reaches center, the bump ocurs.

take this for what it's worth....from AI:


A slight clunk in the steering of a Land Rover Discovery 2, specifically noticeable when turning from right to left at the "12:00" position, is most likely caused by worn out components in the steering linkage, particularly the tie rod ends or the drag link ball joints, which are common wear points on these vehicles; checking for play in these components and replacing them if necessary is the first step to diagnose and fix the issue.

 

panhard bushings or tie rod ends are likely culprits. box is unlikely to be the cause of 1 side only issues. Ball joints on these even with torn boots are last thing I would look at replacing. I've had torn boots for years on both of mine and they are rock solid still..

 

Check everything. Ball joints, rod ends, steering box, steering shaft, inspect for cracked frame where steering box mounts. Make no assumptions to lessen your workload here. You can make your testing order match the good advice you've gotten here, but none of that advice is any kind of certain answer.

Another troubleshooting angle...get a helper to turn the wheel while you lay your hand on different parts of the front end. You might be able to determine where the "clunk" is coming from by how intense, or how sharp vs muted it feels where your hand is. ****watch out for pinch points**** A "stethoscope" (a piece of pipe or hose) might do the same to lead you closer to the source.

Don't think too much, test instead. If you don't know what it is, then you don't know what it isn't, either.

 

the clunk is coming from the steering box as I can best tell. I had my wife move the steering wheel while I was underneath checking the tie rod ends and pitman
arm connection to the rod linking to the passenger side wheel for any wonky motion. none observed.