Front end noise diagnosis - Video Link

[Overland Tailor]

I have a 1997 80 Series with about 85K on it. I'm the second owner and I don't believe the front end has had its complete service as of yet.

On rough roads I get a metallic "banging" sound from the drivers front wheel area at slow speeds when traversing over rough terrain. The truck drivers perfect with good track,no vibrations, no pull. Highway its quiet...

Everything is tight on the exterior and I can only reproduce the noise by striking the tire with a mallet at the 12 O'clock position. No leaks and the grease level is as spec.

The video gives a good representation of the sound.

Thoughts and thanks in advance,

John

***** UPDATED VIDEO OF THE NOW LOCATED NOISE*****

https://www.youtube.com/watch?v=BvjDgNhcYjY

 

[cruiserdan]

That is a good one.

It is a "bell ringer" which indicates to me that two pieces of metal, possibly sheet metal are in very close proximity and the "shake" from pouning the tire causes a reverberating contact.

Possibly the LF shock upper "sleeve" is very close to the lower tube and it is resonating?

 

[Overland Tailor]

Dan,

Thanks for the response.

The noise was present before AND after I replaced the shocks, springs and TRE's... Clearance looks good, but I'll look again for the small stuff......

The noise sounds almost like something is striking/rattling the dust shield, but I cant see anything. I would assume that a "bell ringer" like this would be something exterior and not a bearing or something inside the knuckle?

Thanks,

John -

 

[cruiserdan]

It is probably external. Perhaps the brake backing plate is bent at some point around the circumfrence and is barely contacting the rotor?


On a side note I had a cyclical squeek comming from the RH rear wheel of my SRT8 Challenger and it ended up being the very tip of the swaybar link mounting bolt contacting ONE spot on the big-ass Brembo rotor with every rotation of the wheel.

 

[Overland Tailor]

Dan,

Thats a great thought... Funny that the front pads are the only non-OEM part I've placed on the truck... It needed pads when I bought it and I wanted to replace the rotors and pads with OEM when I did the knuckle re-build this winter.

Initial visual inspection looks ok, But I'll just pull the pads off and try the mallet again and see if that eliminates the noise.

I'll also try sticking a rag behind the dust shield and see if that eliminates it as well as switching wheels to see if perhaps the back is not sitting flush.


Thanks again,

John

 

[cruiserdan]

Take the wheel off and bang the hub/rotor. Follow your ears.

 

[Overland Tailor]

Dan,

I did that and the rotor makes the noise a bit when struck. Caliper is quiet. Thats what make me think it might be the shield, but its very tight when I grab and try to shake it.

I also tried a mechanics stethoscope but the sound is too diffuse to pinpoint...

Thanks,

John

 

[Douglas S]

Have you checked the front wheel bearings? They could be a little loose or maybe the rotor isn't fully seated to the hub.

 

[cruiserdan]

I lean toward contact between the backing plate and the rotor or caliper. With the wheel off and striking the rotor, if it rings try grabbing the backing plate with your hand to act as a dampener and see if the sound changes.

 

[Overland Tailor]

I have not gone inside yet... I was waiting to do a rebuild this winter.

If I can't locate the source externally, I'll be going inside next...

Thanks for the response.


john -

 

[Overland Tailor]

I lean toward contact between the backing plate and the rotor or caliper. With the wheel off and striking the rotor, if it rings try grabbing the backing plate with your hand to act as a dampener and see if the sound changes.

Will do Dan... Thanks so much..

John

 

[cruiserdan]

Have you checked the front wheel bearings? They could be a little loose or maybe the rotor isn't fully seated to the hub.

The sound is too high-pitched to come from that, especially when the vehicle is stationary. There is at least 1,300 pounds of truck sitting on those wheel bearings,. Even if they are loose they won't ring like that.

 

[Kernal]

Sounds a bit similar to tapping in new trunnion bearing races when they bottom out?? IDK.

 

[Stevesnj]

Sounds like a cracked wheel rim

 

[cruiserdan]

Sounds like a cracked wheel rim

Except for the fact that the bell still rings with the tire removed.

 

[bigfj62]

Stop banging on you bumper with the other hammer in your other hand. LOL

That is strange.

 

[Golgo13]

Did you ever figure out where the noise was coming from?

 

[landtank]

sounds like the rim is hitting the caliper. Throw a washer on each wheel stud to space it away and see if the noise goes away.

 

[scottryana]

He says the noise is still there even if the wheel is off and he is just hitting the rotor.

Dan,

I did that and the rotor makes the noise a bit when struck. Caliper is quiet. Thats what make me think it might be the shield, but its very tight when I grab and try to shake it.

 

[landtank]

Missed that. At that point my working theory would be a bent axle if that was a possibility. I had a truck brought to me with a grinding noise. The inner axle shaft had worn through the oil seal and was rubbing against the seat for it.