Clunking sounds

Agree most likely spring bushes

 

Kingpins are indeed part of your steering linkage, as a matter of fact they are a central part of it. They're the pivot points on your front axle. Fall off? Not usual, but they can. More usual is one or both siezing when they wear through their bushings from lack of lubrication. Check them by jacking up your front axle until your tire assembly clears the ground and seeing if you can move the wheel in and out at the top and bottom. Any movement means your bushings are getting worn.

BTW, outside of an "engineer's" wet dream and his computer there are NO points in your steering which are non-greasable or non-wear.

Other "Clunk" spots in your steering:

Front or rear spring hangers.

Loose "U" bolts on your springs. (holds your spring to the axle).

Broken center bolt (holds your spring leaves together and locates the spring on the axle).

Bad drag link (connects your steering box to the kingpins).

Bad pitman arm (lever on the bottom/side of steering box that connects to drag link).

Excessive play in the worm/roller (inside steering box but adjustable from outside).

Loose or broken bolt securing steering box to frame.

Worn U-joint/connector in the steering shaft (from steering wheel to steering box. These often get missed in a "casual" grease job).

Bad upper bearing in steering shaft (steering wheel feels "loose").

All of these are potential disasters eventually.

 

your spring pin shckles at the rear of the leaf spring on each side is what is making the noise. i know, i worked at a pete dealer, the fix...............if you have zerks on your pins loosen the 4 bolts that hold the pins in place take a big c-clamp and squeeze the shackles together, grease them, and tighten the crap outta the 4 bolts, then go to the other side and do the same. this will take care of it for a few months, then you will have to do it again. it is a known trait in the 387 pb that the spring shackles on the steer axle loosen up over time and make a clunking noise when turning. hope this helps.

 

thats what my freightliner dump was doing i replaced the hangers pins and bushings problem solved ......i have a tread on here freightliner spring hanger that has the info on where i got mine from.. mike

 

As these guys have already said, my money is on your spring shackles...

 

also check your cab bushings, they will make a clunking noise when turning too.

 

Agreed. I drive a lot of Kenworths and i believe the mechanics said the clunking when turning was loose u bolts. I now have the same issue w my 2007 volvo 780 and gonna check it out.

 

explanation Above is correct. Mine and my friend" s 2006 387 does it and fix is only temporary

 

The spring bushings have worn into the aluminum shackle, when you make a hard turn the spring flex causes the bushing to POP out of the recess it has worn in the shackle, that's what your hearing.

If the outside facing portion of the shackle is smooth, meaning there isn't a big circular bushing mark around the pin, remove each shackle and reinstall it with the worn inside facing out and the smooth outside facing in, Then say goodbye to that clunk. best of all, it's free.

This is my shackles after I "flipped" them, notice the round pocket around the pins that the bushing wore in.

 

I have a 387. Same issue. Was told to replace shackle springs. Chage every 50k or just deal with the noise.