steering wheel won't return to center
 

2000 grand marquis 150k miles. Im having problems with the steering not returning to center after turning, it wants to just stick there , also has a swaying problem on the highway.

So far i have changed upper ball joints, idler arm, which was worn i thought this was the problem but not, sway bar links and bushings. I replaced all with moog parts. The pitman arm is tight and so are the tie rod ends (inner and outer). I jacked the wheel up from under the control arm and the frame (to check with an with out load) after all these repairs the weels are tight as can be but i am still havinng swaying and the sterring not returning.

I have changed ever lose part that i could find, and i cant figure out what im missing, any ideas or similar problems or thigs to check? Oh ya, also had the alignment done after all this too. thanks.

how good do the sway bar links look? when were shocks replaced?

sway bar links were replaced with moogs, as posted, they look awsome though. Shocks all 4 replaced last summer.

I think im leaning towards the steering gear box as the culprit, it would explain the sterring not wanting to go back to center, but not to sure this would cause the swaying also?

the steering fluid is low.

tire size issue and type of tire can cause issue along with air pressure...

Low power steering fluid and tire size? Really? I need serious inquires only please.

if the tire is low grade and has sidewalls that flex alot or low pressure an make the car feel like it is all over the road... low power steering will cause a whine from the pump or hard steering... i am leaning toward tire issues if lots of things have been changed already... possibly swap rear tires to see if it changes... make sure to put on the recommended tire size since larger side wall tires have a lil more flex to them ...

its not the tires
. trust me