Unexplained Knocking

[sdjerry]

I wasn't sure which section to put this in, so I just decided to post in here.

I've been experiencing some knocking noises coming from the rear of the truck for a few months now. The knocking generally is only heard at low speeds, and it sounds like clanking, it's not really loud banging. It comes and goes, but I personally always hear it whenever I drive the truck at least once.

I took it to my mechanic back on the 7th of this month. And of course they could not duplicate the noise, they said they heard it a little bit while pulling back into the shop's parking lot, but that's it.

So they performed a rear differential service, they also inspected the suspension bushings, steering links, u-joints, shocks, and tightened the wheel bearings.

They found no problems. So I'm stumped, the knocking isn't normal obviously. What could it be?

 

[pedal2themetal45]

If you can get it to make the noise while its ideling use a piace of hose and put one end to your ear and run the other end around the motor and see if you can locate the sound..
Tim

 

[zamos]

Did they check the brakes - also check the spare tire hold down and your exhaust system

 

[sdjerry]

Did they check the brakes - also check the spare tire hold down and your exhaust system

Spare tire was checked and it's secure.

Brakes I don't think they checked, and they definitely didn't check the exhaust system.

What could be causing knocking coming from either the breaks or the exhaust system?

That would help me to narrow down possibilities.

 

[zamos]

If something like one of the brake shoe retainers breaks or fall off for some unknown reason it could be rattling around inside the brake drum and if one or more of the rubber insulators has deteriorated on the exhaust it could be knocking against the body or frame

 

[sdjerry]

If something like one of the brake shoe retainers breaks or fall off for some unknown reason it could be rattling around inside the brake drum and if one or more of the rubber insulators has deteriorated on the exhaust it could be knocking against the body or frame

Thanks for that info, I'll mention this stuff next time I take it in.

 

[Harris]

Hah, zamos, you described what I had to fix about three weeks ago. I kept thinking, "My universal joint just went out."

I jacked it up and spun the tires and all the guts from my driver's side brake were rockin' and rollin' in the bottom of the drum. Luckily I got it before it could ruin the drum.