2500s 75mph+ drone

[Bradjones7105]

I have a 2500s with manual OD, no drones or wines driving round town or cruising, but....when accelerating past 75mph there is a low drone noise, it don't think its a wine, its not high pitched, it's a low noted drone, as said, only appears about 75mph, now I don't know what an imbalanced prop sounds like or what a spent quill shaft bearing sound like? It dosnt come from a specific corner, It seems to just appear through the whole car, anyone had similar, all help appreciated,  cheers

[yorkshire_spam]

Just checking is it 100% road speed related and NOT engine RPM related? (You don't get the same noise at the same RPM but at a lower speed)

I'd assume not, but just to be sure?

The list of possibilities is almost endless... but I'd start with the obvious/cheap stuff....

1. Wheels balanced?
2. Prop balanced?
3. Prop mounting/alignment correct?
4. Diff in reasonable condition?
5. No sign of wheel bearings having excessive play or getting hot after a decent run

After that to me the likely thing is there's a vibration somewhere that's at a resonant frequency of one of the body panels/doors etc.

Also assuming there's no other symptoms like steering shudder etc.

[JohnD]

Brad,

You have an excellent car!  When it has a problem it doesn't whine, but wines!   Cheers!

As this is a high speed problem, I'd add wind noise, possibly due to a loose panel??

John

[Bradjones7105]

Thanks for the replies, it had new wheel bearing last year and they where a good quality replace ment, iv just been under the car, grabing the uj where the prop bolts to the diff, there is some slight movement, so looks possibly its the quill shaft bearing?