RX400h Clunk from Rear and Squealing When Setting Off

ntl · April 16

Hi,

Our RX400h has started making a horrible clunk from the rear when first setting off, regardless of whether it had been sat with the parking brake engaged or not. Often, we'll hear a squealing sound too for the first few seconds of driving. Sometimes we'll hear that clunk or almost a pop a few times on the trip too, but other times we won't get it at all.

A year or so ago we were told we might need to replace a hub a some point - apparently it's near impossible to replace just the bush. I wonder if it's that, but hope it isn't as apparently it's a really expensive part.

Any ideas?

Thanks

ntl · April 17

Could it be related to the mechanism that locks the wheels in 'P' mode?

It didn't do it at all this morning, so it's definitely intermittent.

Spock66 · April 17

1 hour ago, ntl said:

Could it be related to the mechanism that locks the wheels in 'P' mode?

I doubt it as the lock is inside the transmission so you would not get any sound from the rear.

Is there any difference if going forward or reverse, in electric or ICE modes?

maurice1 · April 17

I had a similar sound from back wheels recently.

I thought it was the brakes and when the motorway was empty I accelerated and braked slightly aggressively a couple of times, primarily to test the brakes.

Noise went and fine now.

I rarely use the handbrake but did use it on a car ferry which created the problem.

I believe the rear brake calliper got stuck and it released by itself.

ntl · April 17

2 hours ago, Spock66 said:

I doubt it as the lock is inside the transmission so you would not get any sound from the rear.

Is there any difference if going forward or reverse, in electric or ICE modes?

Thanks. I usually notice it when setting off forward due to parking position at home, I'll have to pay attention when it's parked elsewhere.

ntl · April 17

2 hours ago, maurice1 said:

I had a similar sound from back wheels recently.

I thought it was the brakes and when the motorway was empty I accelerated and braked slightly aggressively a couple of times, primarily to test the brakes.

Noise went and fine now.

I rarely use the handbrake but did use it on a car ferry which created the problem.

I believe the rear brake calliper got stuck and it released by itself.

Interesting, thanks. What I have noticed is that if I do get the clunk as I set off, I'll probably get it at some point while driving, too. Whereas, if I don't hear it at first, the journey will probably be trouble-free.