I thud noise when I turn

Check the spring pins they are probably worn

 

Maybe the bushings, king pin, but I would say your best bet is in the springs

 

Get a helper...turn your wheel all the way left...and all the way right...
Your drag link/pitman joint may be hitting your frame...or your tires may be rubbing your drag link or your hitting your wheelstops..if you have a ross youll need to reset your poppets...if a shepard... need a long thin screwdriver. If its a ross gearbox..get someone thats done it before to help you...sheppards are easy...

 

I had this similar problem in my Freightliner Century. The cause was the U-bolts on the springs gets ever-so-loose, and it allows enough that on a turn, it moves a fraction of a fraction of an inch, but enough to hear it. Get it aligned, torque your U-Bolts, and the sound goes away. That was my problem.

Bouncing down a highway 100,000-plus miles a year can loosen things.

 

Grease your king pins. Anytime I get lazy, the first sign is the popping sound in turns

 

When I got into a truck at my current company, for the first time, my kingpins weren't just thudding or popping on every turn; they were flat out banging. I was genuinely frightened the first time I ever took a right turn in that POS. No longer in it- it's the slave truck. We're just dragging it along until it doesn't turn over one morning and then we'll fix it and run it again until it's either to unsafe to drive or something makes it too pricey to repair. <3 shoestring budget trucking.

 

Could be a broken front leaf spring....although I would describe that as a clunk.

 

Just for kicks and giggles try greasing the fifth wheel. A dry fifth wheel can cause strange frontend noises in a tight turn along with helping the front steers wear out.

 

Leaf spring pins/bushings are worn