Can't find a rattle - Diesel Forum

dlblazer · 11-01-2009, 10:34 PM

I'm sort of embarassed to post about a rattle, but ever since I test drove the truck (and subsequently bought it) the truck has had this rattle. I cannot figure it out and need some ideas.

Heres what I've done/found so far:

- Rear of the truck, slightly more predominate to passenger side
- Sound is a distict metal-to-metal, "tink, tink, tinK"
- Occurs when the rear suspension hits a smaller bump. Big bumps do not make the sound.
- I have grabbed and shaken the exhaust, all the suspension components, dropped the spare, checked heat shields underneath, etc.
- Riding in the bed around the block, I could not narrow it down (have a cap on it)
- Riding in the rear seat with head out the rear slide window sounds like its just behind the cab, and near the middle, maybe more passenger
- Riding in the rear seat with head out the passenger window, I can see the rear tire/suspension and the rattle corresponds to that wheels up/down movement
- Shocks feel tight by hand, but the steel upper portion makes a sounds like the rattle if I tap on them with something --when I unbolted the shocks, they still extend and do not have any obvious oil leaks
- tailgate is not making the sound
- Its not the hub caps
- Can air bags rattle internally? (all mount hardware is tight)

Any ideas?

dlblazer · 11-01-2009, 10:45 PM

The rattle happens much less when I tried airing the air bags up to 50 psi (vs 5 psi).

Even though the truck bounced more, the rattle happened less. I feel it must be related to suspension cycle - shocks internally rattling?

catch&release · 11-02-2009, 09:59 AM

I know how you feel. Rattles will drive me completely bonkers. And they never seem to originate where you think the sound is coming from.

When my Toyota was about 5 years old, a rattle developed that sounded like it was coming from the dash. For six months I beat on every square inch of the dash trying to make it stop. The top of my dash now has splits all over the place because of that. I was just about ready for the rubber room and ready to launch the truck over a cliff. And then one day I perceived that the sound was a little higher than I thought. I kept inching my ear up until it was high on the windshield. I tapped the light bracket on the overhead above the windshield..........and it stopped.

Finally, peace and quiet, but after I destroyed the dash.

Sorry I can't be of more help. That is unless you need someone with a large sledgehammer.

dlblazer · 11-02-2009, 11:26 PM

I think I will start to disassemble things and try driving - shocks, air bags. Theres just only so many things it could be...

KevinTamu · 11-03-2009, 01:22 AM

Is there anyway its the cab vents on the back of the cab between the bed? I don't think their metal, but that would pinpoint almost exactly where your talking. It could be loose and flapping it open and close while hitting bumps.

dlblazer · 11-03-2009, 08:42 AM

Quote:

Originally Posted by KevinTamu

Is there anyway its the cab vents on the back of the cab between the bed? I don't think their metal, but that would pinpoint almost exactly where your talking. It could be loose and flapping it open and close while hitting bumps.

Good idea, but I had my head through the rear slider while my wife was driving, and the sound was further back than that for sure.

Going_Going_Gone · 11-03-2009, 10:49 AM

Do the upper halves of your rear shocks have steel "sleeves" into which the shocks compress? If so, have you tried driving the truck with the RR shock removed? The shock might be hitting that sleeve and causing your clang. Just a guess. Also, are all of your exhaust hangers tight?

0660harley · 11-03-2009, 01:21 PM

Man, when I first read this I thought I might know, but as I finished reading I see you already removed and re-installed your shock. I had a similar problem on the front of my previous f-150. I was getting intermittant, (metal to metal) clanging noises. Turned out to be the top bolt on the pass side shock mount was loose. But, I know how you feel. It was driving me crazy, until it got figured out. I'd say put it on a lift and put your hands on everything, chances are you'll find it. I rolled all around mine on a creeper while it was on the ground and checked/shook everything, I thought. Just totally different perspective on things when it's on the lift.

dlblazer · 11-04-2009, 08:47 AM

Quote:

Originally Posted by Going_Going_Gone

Do the upper halves of your rear shocks have steel "sleeves" into which the shocks compress? If so, have you tried driving the truck with the RR shock removed? The shock might be hitting that sleeve and causing your clang. Just a guess. Also, are all of your exhaust hangers tight?

I'll try removing one shock at a time and driving to see what happens. The upper part of the shock could be doing it.

I think the lift is a good idea too. This truck is so long and with the topper on it, I can't get the weight off the wheels and on jack stands (from the frame) due to limited clearance with the garage door.

I'll post up when I find it.

Thanks for the help.

FJK1 · 11-04-2009, 11:54 PM

Look for a broken leaf in your leaf spring pack. Usually the the rear half of the leaf breaks. Sounds the same as a broken exhaust pipe hanger.

dlblazer · 11-05-2009, 08:35 AM

Quote:

Originally Posted by FJK1

Look for a broken leaf in your leaf spring pack. Usually the the rear half of the leaf breaks. Sounds the same as a broken exhaust pipe hanger.

Will do.

dlblazer · 11-05-2009, 03:10 PM

I took a good close look at the leaf springs but couldn't find any obvious broken ones. They are all tight in the pack (weight is on them). I looked from both the front and rear of the axle and both sides. There could be a crack hiding behind the u-bolts, but so far I see nothing.

I will air up the air bags (maybe put the frame on jackstands and droop the axle if I can find somewhere to do it), to see if any leafs become loose.

Where do they typically crack?

BlueMuleTrucking · 11-05-2009, 08:29 PM

I had a friend do my ball joints, and he noticed my top springs where split in half cut purposely on both sides. and there was some sort of bracket with holes in it just hanging on the springs.. The truck was converted and has all sorts of stupid stuff like that done.

hhall1114 · 11-05-2009, 08:47 PM

I had a similar problem your discription sounds pretty close, grab your drive shaft at the carrier bearing (right in the middle of the drive shaft) if it moves back and fourth a bit your carrier bearing is shot.

dlblazer · 11-06-2009, 08:47 AM

Quote:

Originally Posted by hhall1114

I had a similar problem your discription sounds pretty close, grab your drive shaft at the carrier bearing (right in the middle of the drive shaft) if it moves back and fourth a bit your carrier bearing is shot.

It does move up/down a little inside the metal bracket.

Try it front/back?

How does it come apart?