Droning at 50-60 with the hood up

[fool73]

Just "finished" my engine rebuild and have an inevitable snagging list.
On thing which I can't seem to put my finger on or get my head around is a loud, deep droning noise it has developed which is worst around 50-60 MPH (which is the fastest I have been as running in).
Strangely, I can only hear it with the hood up, all seems OK with the hood down. I'm pretty sure it wasn't doing it before the rebuild so i'm trying to think what was changed with the rebuild that could affect this. It is speed related. If I put the clutch in so the revs drop quickly, the drone stays and drops in tone with the gradual loss of speed.
A few things that spring to mind
1. Could the exhaust have been remounted differently
2. Fitted new gearbox cross member bushes etc - could that make a difference ?
3. Could I have fitted the propshaft differently ? I did not make a note of how it mated with the gearbox/overdrive, or diff. If this is a possibility, should I disconnect/turn/reconnect it, and if so, should I do the overdrive end, the diff end, or both.

[staginhiding]

Sounds diff related to me from your description,or a wheel bearing.
If the latter that should be quite easy to find..

Sam

[jeffsstag]

ditto

[davidf]

Problem with a tyre?

[Stagsongas]

Diff

[jleyton]

I agree diff but could also be exhaust line. Check it's clear where it goes through subframe arms and consider slacking everything off and giving it a shake and even a short run before retightening.

Good luck.

Cheers

Julian

[73stagman]

Anything thats related to the drive line could be the cause of a speed related "drone" Probably more bearing than uj but not impossible for a "just started" uj to make some unusual noises especially when you are listening for them following a new engine rebuild

[stagbeetle2012]

simple way to eliminate engine as cause - take it up to speed when noise starts and hold the clutch down so the revs fall away and the car coasts... Andy

[73stagman]

simple way to eliminate engine as cause - take it up to speed when noise starts and hold the clutch down so the revs fall away and the car coasts... Andy

I think hes done that and the noise is still there and varies with the road speed so the engine noise has been eliminated. I mean that because the engine is new you tend to listen harder for stuff and hear things that might have been already there but went unnoticed.

[WealdenManinKent]

Unfortunately triumph diffs do have a habit of howling! From heralds upwards!! Mine got bad soon after buying but luckily came across another via some helpful people and no more noise
Was around 50+Mph

[GDPR]

Quill shaft bearing......

[fool73]

Thanks everyone for the replies, so I now have a list of things to look at
Tyre
Exhaust
Wheel Bearing
UJ
Quillshaft bearing
Diff
Propshaft

Does the fact I can only hear it with the roof up help narrow it down ?
It's just passed its MOT so would that make wheel bearing less likely ?
Are any of these easy to diagnose ? Tyre and exhaust I can manage !, and I dare say some searching on the forum will help with the others

[staginhiding]

It would help if you can get it up on a ramp,as most of the items listed could be checked in one go..

Its possible that with the roof down the noise/s are being lost..

Sam

[stagbeetle2012]

I recently had a tyre on a modern car that had worn kind of strange, it was a cheaper one with a block tread pattern I bought when faced with a puncture. That made a noticeable and annoying drone/ humming noise at 60 mph that I was convinced a rear wheel bearing. My local garage checked the bearing and changing the tyre got rid of the noise.

[Another Peter]

Droning at 50-60 with the hood up

Has your wife been accompanying you in the car?

I have the same problem in my car (though at any speed...)









































Only joking