Thread: Where is my noise coming from?

Jeez ,if its difficult for you to tell ! then its going to be hell off a guessing game for us !
Out of the 45690 reasons for this Phenomenom , I claim TYRES

Originally Posted by wally

quite loud transmission whine that starts at around 90km/h and goes away after about 110km/h.

Being a diesel .... resonance of the muffler?...
Try this, get it up to speed and put the gearbox in neutral.....

Ah resonance ? at what Hertz ? Ill get out the old 2120 ,bet its a collision of the 2nd and 3rd Harmonic in the ladder Chassis at the specific RPM range . Solution,hang about 1 Kilo of weight about 100MM back from the end of the LHS Chassis rail.or disconnect RHS of Gearbox crossmember ! CLOSE?

my turn
low oil in transfer case or wheel balance.
maybe worn mud and snow tyres causeing vibration like it has tractor tyres on it.

obviously there is the potential for it to be more than one of the numerous possibilities -

FWIW take a good look at the unis, front & back, by taking he shafts off, remembering to mark them so you can put them back in the same alignment that you took them off from.

Originally Posted by 87County

FWIW take a good look at the unis, front & back, by taking he half-shafts off,

Was the solution to "Droning" of my brothers Mazda diesel 4x4

pick from the attached list, its one of my favourites !
Technical problem or defect reported by pilot or crew.Remedial action or answer reported by maintenance engineer
Something loose in cockpit.Something tightened in cockpit.
Left-inside main tyre (tire) almost needs replacing.Almost replaced left-inside main tyre.
Autopilot tends to drop a wing when fuel imbalance reaches 500lbs.Flight manual limits maximum fuel imbalance to 300lbs.
Unfamiliar noise coming from No2 engine.Engine run for three hours. Noise now familiar.
Mouse in cockpit.Cat installed.
Target radar hums.Reprogrammed target radar with lyrics.
Number three engine missing. [not firing properly presumably]Engine found on starboard [right] wing after brief search.
Pilot's clock inoperative.Wound clock.
Aircraft handles funny.Aircraft told to straighten up, fly right and be serious.
Whining sound heard on engine shutdown.Pilot removed from aircraft.
Noise coming from under instrument panel - sounds like a midget pounding on something with a hammer.Took hammer away from midget.
Suspected crack in windshield.Suspect you are right
.IFF inoperative. [IFF = Identification, Friend or Foe.]IFF always inoperative in 'off' mode.
Test flight okay except Auto-Land very rough.Auto-Land is not installed on this aircraft.
No2 ADF needle runs wild. [ADF = Automatic Direction Finder/Finding?]Caught and tamed No2 ADF needle.
Turn and slip indicator ball stuck in center during turns.Congratulations. You just made your first coordinated turn!
Dead bugs on windshield.Live bugs on back order.
Autopilot in altitude-hold mode produces 200 feet per minute descent.Cannot reproduce problem on ground.
Evidence of leak on right main landing gear.Evidence removed.
Three roaches in cabin.One roach killed, one wounded, one got away.
DME volume set unbelievably loud. [DME = Distance Measuring Equipment?]DME volume set to more believable level.
No2 propeller seeping prop fluid.No2 propeller seepage normal. Nos 1, 3 and 4 propellers lack normal seepage.
Friction locks cause throttle levers to stick.That's what they are for.

OK, I realise there are a lot of potential causes for noise, but this is definitely transmission noise, and I'm sure I've narrowed it down to either rear diff or transfer case. I just thought that perhaps, from experience, someone might be able to say one is a whole lot more likely than the other.