Was a Thrum now a Drone

[johnyrover]

Well hellooooo trendsetters.

Got the valley gasket changed about 6 months ago. Straight after noticed a nice thrumming when going up hills. No vibration as such just the thrum. About a month ago the thrum disappeared and now I have a lovely drone and slight vibration starting at about 70kph, at its worse at 80kph, and turning into a subtle vibration at 100kph. One other thing, I cant notice any noise when cold but when warm and going slow after going fast there is a nice steady low pitched drone even down to crawl speeds.
Diff maybe? Cause its always carried on with a bit of whining.

Any thoughts, Brains Trust?

Thanks :D

[mtb_gary]

Does the noise change with engine revs or road speed?

Gary

[discovery39]

I'm gunna go out on a limb here (and possibly get ridiculed), but, have you checked your tyres? When I had my Disco, it did a very similar thing, I was scratching my head for weeks trying to work it out. Turned out to be a faulty tyre, which only became prevalent when the tyre was at a certain temperature/pressure. One of the lugs had become "different" to the others.
That was the official very scientific prognosis.
Just a thought............;)

[johnyrover]

Does the noise change with engine revs or road speed?

Gary

Just road speed. Knocked her into neutral at about 40 and rolled at idle and the sound kept coming. Slower and lower pitch. Also the noise gets consistently higher and harder to detect the faster I go, but does not change with the up and down of gear changes.

Thanks :)

[johnyrover]

I'm gunna go out on a limb here (and possibly get ridiculed), but, have you checked your tyres? When I had my Disco, it did a very similar thing, I was scratching my head for weeks trying to work it out. Turned out to be a faulty tyre, which only became prevalent when the tyre was at a certain temperature/pressure. One of the lugs had become "different" to the others.
That was the official very scientific prognosis.
Just a thought............;)

And a good thought. Now that you mention it, one of my front tyres is a little scalloped. It has been that way since a dodgy alignment. I got it realigned, but the scallop is still there. Also they're not as young and fresh as once they were. I'll try the ol' switcheroo and let you know if it works.

Thanks :)

[discovery39]

If you've had an alignment done and it's still dodge, then jack up that wheel and check the bearings. Same thing happened to my dads P38. We had to get a whole new hub, coz the bearings are pressed in. You can get new bearings separately and if you have access to a press you can do it that way.
We just went for the whole hub option coz we found a good one. While ya in there, check/do the grease for ya CV's.:)
Of course it could be something else entirely!!!!!!!!:D

[johnyrover]

I'll check it out and let you know.

Cheers:)

[johnyrover]

HI guys.
So I ended up swapping tyres. No glory. Then noise got worse after a couple of long trips. Quite bad now so the Mech picked it as a bad bearing. Just the one bad one at this stage so I can spread the pain over a bit of time. I'm going for the whole hub replacement.
Thanks for your input. I'll let you know how it went after he actually replaces it.

Cheers
John :)

[davidsonsm]

What's best advice regarding maintenance on the CVs?

[Keithy P38]

Set-n-forget!

[johnyrover]

Took the plunge and changed the hub myself, (yeah I'm proud). Pretty straight forward, job, and now the noise is gone. Dont ya just love it when you change the right part, especially at $440. Ended up going to a truck mechanic to get the right torque on the axle nut, cause my local guys torque wrench was the same as mine - 150 ft lb. So Rangella is slowly being restored piece by piece. Now that's a good feeling.
Cheers :D