2014 Cascadia clunking sound

do tests.
a. unhook the trailer and drive. make sure the fifth wheel is not hitting to the bottom. if no clicking sound then it was coming from you fifth wheel.
b. disconnect air lines from trailer. gradually apply brakes. if you hear that clicking sound then its coming from the brakes.
c. find a little bumpy road and drive your truck at 20-30mph on that road. don't use brakes. if you can hear that sound then its coming from front leaf springs(or suspension). apply wd40 between leafs and continue to drive . see what will happen. )))

 

I should have been a little more specific. When I said it does it all the time I meant it does it whenever braking when I have a load on. It is worse when it's a heavy load, hot out, or constantly stopping and going when in neighborhoods or in stop and go traffic. It's like the hotter the brakes get the more it clunks.

 

I have been hauling cars 21 years and never heard a truck do what this one does.

 

I had the ubolts on the crossmember tightened down. Took care of my pop.

Empty is no problem but the heavier the load the louder it gets.

Try pulling in to a PA rest area with about 10 inspectors standing around. I thought for sure I was getting stopped when they all looked at me from that pop.

 

Someone figured it out for you. I just saw your post, same thing happened to my 2016 389 Peterbilt.

 

Are you saying it is a flat spot on the S cam or rollers???

 

yeah, that's it, sorta a popping sound i get. I drive a day cab, and it does this. i drove a condo, and it did that.

comes from about the firewall, under the seat area.....

 

it wouldn't surprise me. they hardly torque anything down on those and all kinds of stuff is "loose" like hose clamps that like to leak.

 

The u bolts on the passenger side had to be torqued down. You could not tell from looking down on it, you had to climb underneath to see it.

 

Is the brake spider tightly bolted to the axle spindle?