Rear differential- viscous coupler making a whirring noise while driving. toyota rav4 was issued a recall for the same problem. toyota sienna needs one as well. it is a common failure of the bearing parts.
The viscous coupling on the rear axle of my awd sienna started making noise and needed to be replaced. apparently there has been a recall for the rav4 for the same part, but not the sienna. my auto shop has told me this is a fairly common problem. the bearings in the coupling fail and start to make a very loud whine. toyota says the bearings cannot be replaced and must be serviced as a unit... to the tune of $2300 parts and labor.
Rear differential making a growling noise. was told by toyota that the viscous coupler bearing is bad. cost to replace coupler is from $1900.00 to $3000.00 dollars. car only had 115000 mile on it when it started to make noise. bought a used rear end with 69000 miles on it and again it to is starting to make the same noise at just over 100000. what is up with your rear ends. i can't afford another one. is there a recall?that rear end is only 1yr. old. out off warranty