Drivetrain noises, how normal on 90-16?

[Kalle12]

Moin!

My Iveco 90-16 has been making two noises since I bought it two years ago, 20,000 km+ has been driven with them without issue. Although my friend who is a mechanic said certain noises are normal due to permanent 4x4 drivetrain, I understand some noises are not, and would like to check here.

Noise 1: Only at speeds over 70 km/h
When the truck reaches speeds around 70 km/h and up, a pulsating "droning" repeating sound is heard. It can be felt slightly in the steering wheel but very very subtle. If disengaging the gearbox/pressing the clutch pedal, the sound goes away. Driving downhill with clutch engaged normally, the sound goes away. The sound is only audible when applying torque to the drivetrain, such as going slightly upwards on a slope or applying the gas pedal. The sound changed when I made the truck lighter. Is this a normal 4x4 drivetrain noise that other owners experience? Perhaps it could be a bad bearing.

Noise 2: Releasing clutch pedal during load, a short noise is heard
When releasing the clutch pedal and in gear, if the terrain is difficult, thus putting more strain on the clutch assembly, a light "scream/sing" is heard. The sound only appears when the gear is too high for the low speed, putting more force on the clutch assembly. Once the clutch pedal is fully released there is no more sound. This noise is normally not audible since I drive carefully and on normal roads with appropriate gear selection for the speed. But, if the terrain is difficult, and I select a gear too high for the low speed and RPM, the noise is heard as the clutch pedal is released.

Has anyone had experience with these types of noises with the Iveco 90-16?

[brummiwomo]

Moin Kalle12,

like your "noise 1" I have some similar noise, described in this threat: viewtopic.php?f=31&t=88325&hilit=wummern

But - unfortunately - without any satisfying solution...

R.
Carsten

[IvecoMike]

Morning,

Noise 1 seems like to be normal. I have it as well...

[Kalle12]

Moin,

It is good to know that noise 1 could be normal. The original poster in this thread also had drivetrain noise: viewtopic.php?t=72100 I didn't understand if his noise was similar due to the translation, but he replaced a part and the noise went away. Possibly interesting..

[Kalle12]

Noise #2 has been located and solved. At very low rpm and high torque, the exhaust pipe vibrates in the "sleeve". This results in the "screaming" sound. When the exhaust pipe is warm, the sound ends. In case anyone else has this problem, here is your possible answer