Technical 4x4 TA - Help me diagnoise my odd noise!

[Chernabog]

Hi There,

Been having a few (expensive) issues with my lovely orange panda 4x4 TA of late, but there is one noise that its making that is proving very difficult to identify what is causing it.

Over the last month or so I have had the car in and out of the garage for a number of required fixes (two new tyres, two rear brake backing plates, new front brakes), including a rather expensive rear diff replacement as the old one was making some horrible noises with ELD engaged and the car on full lock. This is all fine and has fixed the relevant issues, but one noise has remained ...

This noise sounds like vibration with a bit of grinding and seems to be coming from the rear of the car, possibley the passenger side (very difficult to pin down). The noise only occurs under the following conditions:

1) Only once the car has warmed up a bit (say 5~10 minutes of normal driving).
2) Only in 4th, 5th or 6th (when in 1st, 2nd or 3rd I cant get the car to make the noise).
3) Only at around 2000 RPM (2500+ and its not noticable).
3) Only at the point of applying power or removing power (so if you are crusing at 50 in 6th gear you will hear it a lot as the revs will be around 2000 and you will just be on the point of applying a little power to maintain the speed).

There is no noticebale loss of power or any degrading effects on fuel economy, its just a worrying sounding and rather annoying noise.Its not the rear diff or CV as the garage has checked those and I am wondering if it might be one of the rear brack backing plates vibrating, as the passenger side one has more play in it than the other side (certainly not loose however) ... but could it be the drive shaft perhaps (although that appears to be fine as well).


Its a very annoying issue and is driving me nuts :bang: So, any suggestions anyone?


Thanks.

 

[Al D]

Dual Mass Flywheel?!

 

[muttleysdad]

Exhaust pipe?

 

[Chernabog]

Hmm, thanks for the suggestions guys, DMF would be expensive so hopefully its not that (surely that would make a noise in all gears at lower revs?)


I have just been digging around under the car and I dont think its the exhaust pipe as that seems Ok (it does have a bit of play, but all the hangers seem good) but I am wondering if its the propshaft ...

When warmed up, the propshaft seems to have a lot more play in it than when cold (not sure if this is normal or not). The centre bearing looks OK and so does the connection to the rear differential, but the connection to the front differential is perhaps a bit suspect ... there appears to be some very heavy grease visible (the finger smudges were me), some of which has at somepoint sprayed onto the plate directly above the connection (please see the image) ... I am guessing that this is not normal and could therefore be the source of my noise?

Quesition is, would this mean new propshaft or something more expensive towards the engine? (although a new propshaft also seems to be very expensive!)

Thanks.

 

[KPat]

I don't think any grease should be leaking out of the rubber cover. I would grab the prop and see if there is any lateral movement suggesting bearings are shot.