Technical 2013 Panda TA 4x4 knocking rear axle

[DavidJonW]

I have a 2013 Twinair Panda 4x4 which makes a rapid knocking sound (sometimes) from the rear axle when making tight lock turns. I've got it booked in to my Fiat specialist to look at next week but any suggestions what it might be so I can go in armed with some knowledge?

 

[WitleyPanda]

It is a 4x4, it uses the ABS system as its LSD. On a tight turn it maybe assuming that the outer wheel has lost grip and rapidly fires the brakes. The rapid noise being the ABS action? There is a gyroscope in the vehicle and would have thought that the software would use the change in direction of travel and/or steering position to augment the situation? So hardware issue with brakes/diff or software issue, actually sensor issue with gyro or steering position sensor. I have no knowledge of how the software actually performs, but from an engineering standpoint this would seem logical. Potentially issue is the differential on the rear axle, not “liking” having to work so hard? Check sensors working, check brakes, does same thing happen on both sides etc.

 

[Herts Hillhopper]

I’d suggest looking closely at the rubber support for the centre bearing on the propshaft (in the metal cage half way along). The rubber ring fails and can lead to the propshaft knocking.

 

[TTR]

Eh up

Just to add to Herts thoughts, would also be worth checking the UJs at either end of the prop shaft, it’s a know failure point and as we know noises can travel and appear to be coming from elsewhere

Hope this helps