Classic Alfa Forums

Back out on the Cat and Fiddle with the sud after the restrictions were eased.

Got an annoying whine from the front over 40 mph in 4th/5th.

Its outboard vented disc, Sprint type.

The gearbox seems good.....goes thro all the gears ok, and no synchro issues.

Could be gearbox bearings/diff bearings/wheel bearings?

How do I know which?

The only clue is the MoT guy said the NSF wheel bearing had slight play........I replaced it, and the whine seemed to be less.

Maybe I should check/retorque the OSF wheel bearing.

Don't want to change the gearbox, and discover the noise is from somewhere else!

I'd check the gearbox oil level first

Sorry, I should have said Dave....its full up!

alfadave wrote: ↑Thu May 14, 2020 9:26 pm Back out on the Cat and Fiddle with the sud.

Now I am envious.

Its not a whine to be envious of!

Anything that rotates can cause a whine, from the tyres to the engine.
Many is the time I've had cars brought in with a "noisy wheel bearing" that was just an aged hardened tyre.
You can easily sperate it being an engine while to a driveline one by dipping the clutch while moving, if the engine drops to idle and the whine is the same you can rule out anything engine wise.
If it stays on then you've got tyres/wheel bearings/driveshaft cv joints/diff bearings and internal gearbox bearings to shuffle through deciding which it is..

Do not ignore it being from the back wheels either....so many times....

On the Snake Pass today.....
dropped it into neutral with the clutch out.............the whine seemed to reduce.

Tried a refill with fully synthetic..... a bit quieter......so am going to my local garage tomorrow.
He will support the front,over the pit, whilst I drive it.
He will listen with a stethoscope.

Ran it in 4th gear at 40mph supported over the pit.
The whine is clearly coming from the diff.

Is it possible to swap that with the gearbox in situ?

To answer my own question......I spoke to Charlie Skinner.

Yes its possible to change the diff with the gearbox in situ......

But not advisable unless you are fully competent at gearbox work.