1991 XJ6. I have steering wheel wobble at virtually any speed. Under 20 mph it shakes the steering wheel and the entire front end. I have replaced the two tie rods (ends were good) as they where very loose, but it is only marginally better. There is a low irregular noise that could be the steering pump, but I am not sure if that could be the source of my problem or simply a reaction from the wheel wobble. The wheel bearings, rotors and caliper (one side only was bad) have all been replaced. I am putting new shocks on this weekend and then replcing the tires (they are old but not so out of round as to be causing low speed wobble), but something tells me that it could be the pump surging pressure in the hoses or something. Anyone out there ever had this problem?

 

Are you sure it isn't the tires? That's my first thought.

Cheers
DD

 

me too on tires, along with possible inner tie rods inside the steering rack

 

It could be the tires, but they would have to be visably out of round to shake that much. Will be replacing tires next week
Thanks

 

Both inner tie rods were bad, with a lot of loose play. After replacing the knocking noise went away and the ride was better, but wobble is still very pronounced.
Thanks
Steve

 

Why dont you swap them front to rear first

 

I had my son drive towards me slowly (5-10 mph) and observed both tires moving side to side, so it is not the tires. I am wondering if the steering pump is creating an osillating pressure that moves the rack rapidly back and forth. There is not a lot of play in the steering wheel. It moves with the wheels.

 

Maybe I'm not understanding you but I don't see how the tires are disqualified as a possible culprit. If they have shifted/broken belts or damaged cases you will often see the tire actually move left-right.

Are your wheels bearings loose?

How about the steering rack bushings?





I guess anything is possible but what you've described would be pretty strange. I'd eliminate the more obvious candidates first, personally.

Cheers
DD

 

I will be replacing tires and shocks, then 4 way alignmentm. I still suspect that something is up with the pump and though someone on this forum might have had a similar problem. I have jacked up the car and spun the wheels and they show no aigns of being out of whack. I did exchange fluid in the pump several months ago and disconnect the return line to siphon off the old fluid. I did not bleed the system and not sure if that is necessary or where to do that. Is is possible that there is air in the system?

 

Normally just a few turns lock-to-lock will burp the system.

Cheers
DD

 

I am trying to work out how a power steering pump/fluid circuit can make the steering wobble. The pump supplies fluid to the rack and with no steering load on, i.e. car is going in a straight line, the fluid should pass right through the rack valve through both passages of the rack (left and right side of the power piston) and back to the reservoir. There are no electronics to worry about. If a steering load is put on, the rack valve detects this, (using a small torsion bar), and prevents fluid exiting from one side or the other of the rack allowing pressure to build one one side, and thus assisting the driver steering effort.

Wobbles invariably come from imbalance of wheels and tyres, or distortion of the same due to damage cause by kerbing etc. However, there is much emphasis on cleanliness and avoiding dirt entering the fluid circuit when dismantling, so I suppose dirt trapped in the rack valve might cause intermittent pressure build up in the rack. Unusual though.

 

Thanks all for your input. The steering fluid is clean and the level is constant. When I replaced it only the return hose was disconnected and reattached after the fluid came out clean. It was dirty before the flush and I suspect non-spec fluid was used and not the mineral based fluid. Before the change the steering was hard to turn and now is much better, but still feels like it takes more force than my mercedes for instance. At this point there are a lot of factors that when combined are having a dramatic affect on the steering.
Replaced so far:
wheel bearings, caliper rt. side, rotors, brake pads, tie rods at steering rack, boots, brake fluid

 

At the risk of beating a dead horse.....

And FWIW.....

And even though it might not fix the problem.....

Personally, I wouldn't invest any more time or money in this problem until the tires are replaced. Or at least swap fronts-rears to see if the problem changes in any way.

Cheers
DD

 

And another thing would be to take off the pump drive belt, and drive without PS fulid circulating. If the wobble is still there it aint the ps system. OK the steering will be hard to turn, but you will only be going slow speed.

 

OK all you guys who said it was the tires were right. Replaced the tires yesturday and all is well. One of the tires was completely destroyed on the inside, although from the outside it looked ok. I wouldn't have believed a tire could make the car shake that much, now I am a believer.
Next task is to find my oil leak. It appears to be coming from the front main seal. Anyone have any thoughts on this repair?