2009 Jaguar XJ, currently 77k miles.
Power steering lockup at left stop.

I bought the car in Sept 2018, with 72k miles. Before looking at the car, the owner informed me that there was a problem with the steering and that his research indicated it may need a new Rack. On the test drive, the steering was VERY stiff and would bind in any position. I needed both hands to steer and the wheel didn't want to naturally return to center after a turn so I also had to steer back to center.

I bought the car and drove 225 miles home. On a diagnosis ride the next day, I noticed that there had been some improvement to the steering effort. So I suctioned out the PS reservoir, refilled, turned to stops, drove around a bit, then repeated 2 more times. Over the next 300 miles, the steering steadily improved and got to near normal. The steering wheel would now self center after turns, but it feels slightly stiffer than normal. The only remaining issue was some binding and increased resistance on low speed turns while parking, only when the wheel is turned to near the left stop.

5k miles latter...
Last night the steering locked up after turning to the left stop while parking and no amount of effort will turn it. The steering won't budge at all. I've tried with the engine running, engine off with key on, in various gears, at idle, 2k and 3k rpm. I've also tried while the engine was hot, cold, in-between, and after several hours of being off. In all cases, I cannot turn the wheel at all.

It seems to me that there should be a valve somewhere in the PS system that directs higher or lower pressure to a side of the rack as needed?
I found the following on the forum...
So what is everyone's opinion? Does the rack need to be replaced? Is it this Servotronic module thing above? Is the Servotronic module integrated into the rack or is it a separately serviceable module?

 

Hi Victor,

While it is possible that part of your problem has to do with the operation of the Servotronic solenoid, I doubt it has anything to do with the lockup you are now experiencing. The solenoid only varies the power steering assist between maximum and minimum values for optimum steering feel at both very low speeds (e.g. parking) and very high speeds. The solenoid only varies the hydraulic power assist and has nothing to do with the mechanical movement of the rack and pinion gears.

I think you need to fully inspect the entire steering system, including the inner and outer tie rods and the steering column, for any signs of damage. You should also check your vertical links/steering knuckles, ball joints and control arms for any damage, or for any obstructions in the suspension, perhaps from a broken component or foreign object, that may be preventing the steering system from moving properly.

Before you condemn the steering rack, it would be worth disconnecting both outer tie rod ends from the steering knuckles and then attempting to move the steering wheel through its full range of motion lock-to-lock.

To answer your other question, yes, the Servotronic solenoid or transducer is available separately. See part 13 in the diagram below from jaguarclassicparts.com:




Please keep us informed!

Cheers,

Don

 

I have disconnected both tie rods and the steering wheel still will not move.
I have also detached all hydraulic lines... Still won't move

 

I guess one more step you could take would be to disconnect the steering column/swing link from the top of the steering rack and see if the steering wheel will move freely, which would rule out an issue with the column universal joints.

 

My suggestion is to start the car, keep in Park and forcibly try to turn the steering wheel further in the direction of the wheels. I'm guessing that the steering column locking mechanism is jammed.but will release when the stress is removed.

 

Like Toyman says, total inability to move the steering could be the steering lock not releasing. This is operated by a solenoid, and you hear it operate when you insert the ignition key. I can't remember anytime in my motoring career anybody reporting total seizure of the rack itself. I suppose a tooth could break off and seize the mechanism, but it would be a very rare event.

 

Any tips on getting the steering column link disconnected from the top of the rack? I had to give up last night due to darkness, but I'll try again tonight.

Also, my saying that "I cannot turn the wheel at all" is not accurate. I'm definitely at the left stop and i can move the steering wheel a few inches to the right and back again. I also hear the power steering pump strain at either the left or right limit of motion.

It's the wheels that would not move at all. But now that they are disconnected, Both steering knuckles move freely.

 

There is one pinch screw that needs to be removed. I can't remember on the X350 if that screw has a hex head or a male Torx head, requiring a female Torx "E" socket. With the screw removed, you have to either pull the column up off the rack splined pinion shaft, or if it's too tight, use a pry tool of some sort to carefully pry between the rack and the end of the column to pry it upward and off of the pinion shaft.

 

I've replaced the steering rack and the tie rod ends. Everything seems to be working now.
The rebuilt rack was $199 from Detroit Axle, which I was able to pickup locally.

 

I'd be interested in knowing why the rack locked-up.

 

Awesome!

I had a regal with a bad rack, it would catch and loosen, catch and loosen. It was going to need a new rack.

 

I have to take the old rack in as a core. I'll ask them to let me know how the rack failed

 

Near the end mine was sometimes seizing up on a low seed sharp left turn, as in a parking maneuver. But i was always able to bounce the steering wheel further left and it would free up. In the final instance, I couldn't free it.

I thought it was a hydraulic pressure seizure, but it's not. I can't move it even off the vehicle, so it must be a mechanical failure