aeroelasti

Got an oil leak from where the right rear drive shaft connected to the rear diff. Brought it to a garage and the guy said check the breather valve first and see if it blocked.
Anyone knows how does it look like and how i remove this?
Thanks.

nipponbird

A diff breather valve is usually installed at the highest point of the diff, in other words on top, to serve as a vent for a release of gasses caused from heat. It can get blocked if the vehicle is used on dirt roads. Usually it can simply be screwed out and cleaned. I would advise that you replace it with a new one and remember to take special care that no dirt enter the diff if you should replace the breather.
I also wouldn't be surprised if the leak you mention, persists, as I cannot see why the diff would choose a particular oil seal out of three as a substitute for the breather valve. Breather valves are seldom the reason for a pinion or side shaft oil seal to go South. Breather valves had the nasty habit on older 4x4's to suck water into the diff, because the sudden cooling down of a diff if you do some wading, causes a vacuum, which is filled through the breather with water from the stream you're traversing, otherwise they are quite well behaved and I believe manufacturers have by now solved the drinking habit too.

aeroelasti

Thanks for the infor, this is helpful.

I have managed to locate it and remove it for cleaning. Mine was quite clogged. When I first unscrew it, I can hear hissing noise lasting for a few seconds, suggesting pressure within, The car was cold, not being driven before I unscrew the valve.

Anyway, cleaned and put it back. The leak has now changed from drips that can be seen on the garage floor to nothing in the last 2 days (I put a card board underneath after driving the car).

On a closer inspection, it is still wet around the shaft area, so still leaking but very slow. Remove the filler screw and felt that the fluid is still quite full. So it won;t be a hurry to change the seal.

Anyone know the OE part number for the Seal? I might get one first and wait till things get worse and be ready.

Thanks,

nipponbird

I assume you have changed the diff oil at the same time. Not impossible that a service guy overfilled the diff at some service and the pressure is still too high, hence the oil sweat. I'm glad that the problem was only the breather, had to change a pinion seal on a 4Runner I had and was it a dog to set the pinion backlash again, but of course with a side shaft seal you don't have that factor.

aeroelasti

Thanks Nipponbird. To replace the side shaft seal for a 2004 rx, I assume the whole shaft will still need to be pulled out to access the seal, which mean the whole brake assembly and bearing need to be separated from the shaft.

Thanks.

nipponbird

When I got my second gen RX350, the only workshop manual I could source was the Highlander/RX300/330 Haynes. According to this manual, you have to remove the sides haft, by loosening the the balljoints in order to swing the hub/disc assembly out of the way. Of course you have to loosen the spindle nut to pull it out of the hub with the side shaft. With the side shaft removed, you can remove the flange from the diff and simply pry out the oil seal. I prefer the elementary set of plastic discs you can purchase from spare parts stores to seat your replacement oil seal squarely and without damage. Maybe a bit paranoid, but I always buy two oil seals, cause it can spoil your day if you accidentally apply pressure to the seal in the wrong place and it bends in a way in which it can't seal properly on the shaft. Remember to pack the seal with a good quality grease on the inside to prevent dry running for your first couple of yards after installing. Suppose you know all this stuff, but just saying.

aeroelasti

Thanks for the information, really useful. I won't be doing this just yet, will wait and see.