Rear differential failure other problems to follow ?

[friendly_jacek]

Back in 2007 (IIRC) when RAV4.3 were fairly new, someone in Australia racked tons of km in new RAV4 and had rear diff failing right after the warranty period. I posted about it on this forum back then. It was an early indicator that the diffs are not the strongest point of this car.

If one wants to prevent it, early and frequent fluid replacements with SPECIFIED oil are in order. Note that FSM calls for SAE90 for over 0F and 80W90 under 0F. That is an indication how hard that small diff works and average 80W90 or 75W90 is not going to cut it IMHO.

[pepepeter]

Originally Posted by friendly_jacek

Back in 2007 (IIRC) when RAV4.3 were fairly new, someone in Australia racked tons of km in new RAV4 and had rear diff failing right after the warranty period. I posted about it on this forum back then. It was an early indicator that the diffs are not the strongest point of this car.

If one wants to prevent it, early and frequent fluid replacements with SPECIFIED oil are in order. Note that FSM calls for SAE90 for over 0F and 80W90 under 0F. That is an indication how hard that small diff works and average 80W90 or 75W90 is not going to cut it IMHO.

I recently drained, flushed, and refilled both trans case and rear diff with valvoline syn 80w-90. 08 Rav4 has 51k miles and both came out nasty drak green; rear was worst. But now i have a slight squeak almost squeel (think mouse wheel) when i do a quick acceleration. What the hell is that all about? There are no clunking or hard shifting sounds, but it does feel a lot smoother and it seems as though i hear a swirling sound that i never heard before. Its not loud at all just audibly different.

[ed011826]

If the sound sounds like a school bus whine that would be what I heard. It started a 10:00 am and five hours later it was in the shop where I was told I needed a new differential. There was never any noise before that. No clunking no hard shifting.

[JuneBug]

For anyone who's interested, this document explains in detail how the rear differential and electro-magnet coupler work:

http://rav4world.com/pdf/2006/rav_diff.pdf

[pepepeter]

Originally Posted by ed011826

If the sound sounds like a school bus whine that would be what I heard. It started a 10:00 am and five hours later it was in the shop where I was told I needed a new differential. There was never any noise before that. No clunking no hard shifting.

Ok at first reading your post i was worried. But i honestly do not believe it sounds at all like a school bus whine, but then again i dont really know what that sounds like. As i mentioned it is a faint sound but with my ocd i can hear it. I hope its not the same situation as you had. What is your status?

[ed011826]

It was the rear differential as replacing it solved the problem. My status is 2800 dollars poorer and a bit miffed at Toyota.

[anchorman]

The rear diff on a RAV contains a multi plate clutch. Normal wear of this clutch means the oil gets contaminated with wear debris. It is vital that the oil be changed every 2 years or 10k miles. Otherwise the debris will destroy the diff bearings.

[Carbon]

Originally Posted by anchorman

The rear diff on a RAV contains a multi plate clutch.

I doubt that.

[RF Overlord]

I believe anchorman meant that the electric coupling, which is part of the differential, has a multi-plate clutch.

Does anyone know if the electric coupling is lubricated by the diff oil...I would ass-ume it is...or is it self-contained?

[Carbon]

Originally Posted by RF Overlord

I believe anchorman meant that the electric coupling, which is part of the differential, has a multi-plate clutch.

Does anyone know if the electric coupling is lubricated by the diff oil...I would ass-ume it is...or is it self-contained?

It was the clutch plate material I doubted. I suggest Dr. Dyno has done more study on this than we have: rear differential although Anchorman rear differential on the same thread talked of the clutch material too. So maybe Anchorman is right. Maybe somebody will dissect a failed part. Fortunately there do not seem to be a lot of failures.