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Evening all!

Just recently joined the Rav4 world by means of a 2007 Rav4 CV 2.4L 4cyl

Vehicle drives great, and has an almost clean bill of health from my local mechanic (only exception being 2 x leaking shocks).

However, under light acceleration around the 40kph mark, the vehicle exhibits a pulsing, harmonic-like droning noise (kind of wooo-wooo-wooo) that disappears when I let off the accelerator, accelerate more firmly, or the speed increases enough (50ish kph).

What is likely to be causing this?
 

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Registered
Joined
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1 Posts
Evening all!

Just recently joined the Rav4 world by means of a 2007 Rav4 CV 2.4L 4cyl

Vehicle drives great, and has an almost clean bill of health from my local mechanic (only exception being 2 x leaking shocks).

However, under light acceleration around the 40kph mark, the vehicle exhibits a pulsing, harmonic-like droning noise (kind of wooo-wooo-wooo) that disappears when I let off the accelerator, accelerate more firmly, or the speed increases enough (50ish kph).

What is likely to be causing this?
I foolishly bought a used 4 cylinder 2007 Rav4 4wd with the identical problem. I am theorizing that the reason for the appearance/disappearance of the sound at 40 kph is because this is the speed at which the electromagnetic clutch in the rear differential disengages completely. The dealer has analyzed, (at a cost of about $300!), the problem is a gear issue in the final drive assembly. Repair would be new rebuilt transmission $Can8000 or replace the pinion gear and ring gear at about $Can3500. Apparently the ring gear/pinion gear assembly has to be "lapped" to mesh noiselessly and on some units this wasn't done properly. The parts numbers have not been superceded so if I did replace the ring gear/pinion gear it there is no guarantee that it would solve the noise problem forever I understandthe problem is more prevalent on the V6 models but it does occur on the I4s as well. Anyways the transmission works fine and conventional wisdom, also the opinion of the dealer transmission expert, is that it is basically a nuisance issue and the chance of transmission failure is reasonably low although not zero of course. I am going to try and live with the noise.
 
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