My 2010 RAV4 V-6 AWD recently had the viscous coupler on the rear differential replaced under a little-known warranty extension by Toyota. The dealer also advised me that the rear driveshaft was showing signs of wear and recommended replacing it as well for $1,400. They said that the viscous coupler would not be warrantied without this extra repair. No noise or symptoms of this noted in driving.
Your rear driveshaft, also known as a propeller shaft, connects the drivetrain to the rear differential of your AWD vehicle. It employs multiple universal joints (u-joints) to facilitate rotary motion, allowing the shaft to rotate freely through all necessary angle changes.
Typically, these u-joints are replaceable on larger vehicles, as the shafts are also larger and easier to work with. Given the smaller size of the shaft and u-joints, most manufacturers of mid-size SUVs opt to offer only a costly, complete shaft. When a u-joint dries of its lubrication and begins to seize, it will start to vibrate and steadily get worse as it approaches complete failure.
I assume that the rear u-joint, which is located adjacent to the viscous coupler, was showing signs of wear. Since seizure of the rear u-joint is not uncommon for your vehicle, the dealer likely feared it would soon fail, potentially damaging the new viscous coupler. While it sounds as though it is too late now, there are aftermarket shafts available that would have offered financial alternatives.
I have a 2005 Nissan X-Trail. Last month I had the resonator and tailpipe replaced. Since then, my rear hatch electric lock, my rear window defogger and my rear licence plate light have all stopped working, but my rear wiper still works. The muffler shop feels it is a coincidence that this happened after their service because they only worked under the vehicle and didn't disturb or even see any wiring. Is it possible that the muffler shop could have caused these problems when working under the car? If not, what else could cause these issues?
All repair shop owners are well versed in this phenomenon. It goes something like this. A customer leaves after a service and comes back later with a “ever since you fixed my brakes my car won’t start” statement or something similar. Jan, it’s certainly not my intent to belittle your frustration, but you have touched upon a sore spot that I’m sure all technicians and owners can relate to.
Fortunately though, I am familiar with the fix. When you open your rear hatch and look up at where the hinges are located, you will see a black rubber boot going from the body of the car to the tailgate. This boot houses the tailgate wiring. Years of repeated opening and closing the tailgate will stretch and fatigue the wiring located within. Have a repair shop pull back this rubber boot and they will find three or four broken wires. It should be an easy fix and most definitely a coincidence.
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