Toyota Nation Forum banner

1 - 3 of 3 Posts

22 Posts
Discussion Starter #1
Getting noise from one of the rear axles or the rear motor on my 06 Highlander hybrid.

Im calling it the rear motor but maybe it’s called a differential even though it’s not connected to the engine.

I’ve got 394k on the vehicle.

I have noticed the rear motor has started to ooze out some of its rear atf fluid. The rear motor is oily.

I pulled the upper plug on the drivers side of the rear motor and atf started to ooze out so I figured the rear differential fluid was good.

But I’ve been getting this thump thump thump noise that used to only be at 65 mph, now I’m hearing the noise as low as 40 mph. It sounds similar to a bad tire with a slipped belt or a bearing with a rough spot on it.

I checked my bearings they are good. My tires look good too. I doubt I have a failed rear axle as I’ve never had a front fail on the car.

So then I was under it and found a fill plug on the PASSENGER side of the rear diff/ motor. It was the same Allen head style drain fill and drain bolt as the other side.

I put about a half a quart in till this top hole on the driver side wouldn’t take anymore.

The noise seemed to quiet down and was only evident at 70 mph after adding the red atf fluid to this rear diff.

Then after about 50 miles of driving the noise started getting bad again to the point where you hear it around 40 mph.

I bought a chassis ear and clipped it to the rear diff. Yes I hear noise I hear a light thumping in the chassis ear so I THINK it’s either the diff failing or one of the rear axles. But I have no idea how to determine what.

Also anyone ever replace the rear motor / differential or a rear axle. I’ve done front axles before but nothing in the back.

6,613 Posts
To add pictures, when posting, switch to "Go Advanced and them "Manage Attachments" or Drop Images Here" will appear.
I think, you have bad tire. That's what I think.

Also, rear diff takes 2.4 qrt of ATF. Adding half didn't do much. From what I recall, both drain and fill plugs are on the same side.


1 - 3 of 3 Posts