Thud Noise from Passenger Footwell

[therealsethallen]

So, on the way home from work tonight, I noticed a thud coming from the front passenger side of my truck. It is prevalent only when stopping with at least 50% pedal pressure, or when letting off the brake. Took my buddy for a ride and he swears it's coming from directly under his feet. When I got home I crawled under the truck to see what's what. Couldn't see anything out of the ordinary. It has gotten worse in my driving around town since about 6. Had to go out and do a few errands and it seemed a little more loose than usual.
Everything appears to be tight. Not perfect, but tight. Sway bar links look decent, upper ball joint is ripped but the noise is lower. Thoughts?

 

[Mooseman]

Brake caliper or bracket? I lost a bracket bolt once, not fun. Been using blue Loctite and breaker bar ever since to tighten them.

 

[hockeyman]

Agreed, I'd look at the brake caliper bolts, and then inspect to see if the brake pad guides/shims are loose *or even if they're still installed.

If good, I'd start looking at the front passenger side 4wd disconnect, axle, etc.

Even though you mention that the UBJ boot is ripped, check to see that underneath isn't completely dried out and/or loose. If it were me, I'd get a new boot for it, or just install a completely new ball joint. They're not difficult to replace and you can rent the removal & installation tool at most auto stores for free. Again, just me...

 

[therealsethallen]

Got it up in the air today. Confirmed upper ball joint. I don't understand the fact the truck does 75-80 up the highway perfectly straight, without any wobble in the wheel, or anything.

 

[Reprise]

Both of my UBJ were bad (torn boots), and 70mph or so was no problem. Now sometimes when I would stop harder than usual, I'd get some shimmy, but that wasn't often.

Generally, rule of thumb is to replace a ball joint w/ a torn boot. Apparently, the GMT360s like to snack on the uppers, and after having replaced them (never having done one before), I think I could prolly do one in 30min now, and I have 4wd.

I'd replace at least the passenger side and give it a test. It won't be wasted time / money.

While you've got the front wheel off, take a look at the brake system on that side - have someone modulate the pedal, if needed. Since the noise is only heard / felt during application/ release of the pedal, it seems to be the place to start.

Check your rotor, too, for signs of obvious high spots, etc. Warpage will be very hard to discern unless it's really bad, and if so, you'd have been feeling that sooner, especially at highway speeds.

 

[therealsethallen]

I plan to put a new set of brakes on all four corners, since the fronts seem to dust quite a lot.