Strange resonance

[ekkoh99]

on smooth road, I notice a resonance and cabin vibration at 1400 RPM. could be fourth or fifth gear. If i hold the speed/rpm its there. If i go in to neutral of speed up or slow down, it goes away. Any ideas? I did have the front suspension refreshed this year. no vibration in gear at stop. axles are raxles.

 

[zzdiesel]

Possibly lack of a balance shaft.

 

[ekkoh99]

I had the balance shaft upgrade, geared done 14 years ago.

 

[PickleRick]

Axles and tires are always a good start

 

[redsled17]

I believe I have the same thing after installing a raxles replacement driveshaft on the passenger side. It occurs between 70 - 80 kph. Car is stored for the winter so I can’t confirm if shifting in neutral makes it go away. Cant conclusively say it’s the replacement driveshaft but with my previous Chinese axle I dont recall noticing this resonance.

 

[CantWrite]

Engine/Trans mounts.....?