tora302

Hello All

I have a 2010 RX350 3.5 AWD. The AWD Hydraulic Coupling on my rear differential is making the dreaded howling / whining noise indicating the bearings inside are shot. I believe the Coupling part number to be 41303-48010, which has been superceded by 41303-48013. To buy this Coupling new is well over $1000. Siennas and Rav4s have a similar problem, and the RAV4 has a TSB to fix this under warranty. I am trying to determine what bearings I need before cracking the unit open. I have read thru the toyotanation forums for the Highlander, sienna, venza and RAV4. The 2014+ Highlander uses the same coupler as the RX, but I cannot determine which bearings that uses either. Does anyone have difinitive information on what bearings our units use? Otherwise I will have to wait until my summer car is out of storage to rip mine apart.

Thanks

Non

Can you tell us if the oil in your rear differential was always changed on time?

tora302

I cannot be sure as I bought it with 100k miles on it. I changed the rear end oil at about 130k miles and what came out looked dark and used, but no water, no metallic shavings or flecks. I have concluded it is the coupler based on this fluid change and on use of a stethascope. I at first suspected the rear diff, but placing my stethascope on the coupler produced the same bearing noise but much louder than when listening to the diff itself. The vehicle now has approximately 138k miles, the noise has been loud enough to hear inside for the last 1000 miles. I drive roughly 400 miles/week.

tora302

Another option I have is buying an entire coupler / diff assembly from a wrecker, but it would be preferable to spend under $200 on bearings, o rings, and dust shields to solve the problem. I fear a used unit may have the same issue as mine. Have also seen some CV shaft compatibility issues between the Highlander and the RX on the internet.

Jeff Lange

iTrader: (1)

I’m not aware of common issues with the RX/Highlander unit (compared to the RAV, at least) and have never opened one up, not seen one disassembled. You may be stuck having to disassemble it first if you want to attempt to repair it.

Jeff

afpj

When I Google that part number there are a lot of listings on eBay. None of them appear to be refurbished. Don't think this is a part that you can take apart and replace bearings simply.

Kostyan

Hey guys. Our '13 RX displays Check AWS system on the dash and computer throws c1299 code. We are being told by mechanic friends that we need to replace the coupler but our car is not
making any noise. Does anyone know any other troubleshooting steps to make sure its the coupler?
also, how big of a job is it to replace the coupler, in hours?

Clutchless

There may be some useful info at the 2014+ Highlander forum as they are more hands on with repairs:
https://www.toyotanation.com/forums/...2014-2019.333/