If anyone does DIY on their RX, they know how much of a pain in the behind the rear differential’s allen key drain and fill plugs are. They are made of a soft metal and love to strip out, especially in areas with salt and rust. These plugs just don’t have a good way to accept all the torque it takes to crack them loose.

Like many Toyota/Lexus cars. The plugs are a standard size of M18 x 1.5. This is shared with the transfer case which uses far superior 24mm hex head plugs. I decided to grab some for my differential and couldn’t be happier.


Fill Plug: 90341-A0002

Drain Plug: 90431-18057




Transfer case plugs installed!

 

That’s a good idea to swap them out. I’m going to tackle the fluid swaps this weekend. I’m in NJ so I’m assuming mine are going to be rusty. I’ll check with my dealer to see if they have two of each, can’t hurt to put new hardware on both. Are the magnets/thread heads exactly the same?

 

Well done....

 

Good find.
I think you transposed a couple of digits on the drain plug and that it is actually 90341-18057.
Both plugs are available on eBay.

 

Might be a Toyota part number Lexus parts department couldn’t find the part numbers in his system.

 

Those shallow plugs are super easy to strip think I prefer Allen in this application.

 

Toyota and Lexus use the same parts number system as they share a great number of parts. Note that the first plug was 90341. I Googled the number of the second part as listed 90431 and got corrected results for 90341.
That 90341-18057 is for a differential or transfer case drain plug.https://www.yotashop.com/drain-plug-...n-90341-18057/

 

Apart from the 24mm hex head, the plugs are identical in size, threads, magnet & shape. Had to soak the plugs in penetrating oil, wire-brush them, then scrape them out with a flat blade screwdriver. The fill plug gave me so much trouble that I had to use a little heat as it was stripping out. Make sure to hammer your socket in and put a lot of pressure facing downward to prevent slipping.

I did the transfer case after, the equally rusty plugs broke free with a 24mm 6-point socket. They are a little shallow, but work fine if care is taken and they aren’t over-torqued. I vowed never to deal with these stupid allen plugs again after both my diff plugs on my 2002 Highlander stripped out, whereas the t-case was a breeze. Any M18 x 1.5 plug should work, but the Toyota ones were the cheapest for me.

 

Thanks for the tips I just put the front wheels on my rhino ramps and the rear up on jack stands. I have allot of surface rust but everything else looks great underneath. I blasted a ton of pb blaster on the 4 bolts to let them soak overnight. I bought a high quality snap on Allen socket, 3 bottles of Amsoil, a pump with hose, oem crush washers. I dusted off my creeper putout my ratchets and I’m ready to go! Let’s see tommorow what good times this project is going to bring!!!!

 

Good stuff! Sounds like it should be no problem and you're prepared for anything. Would love to hear an update! Plug torque spec is 36 ft lbs for all four of them.

 

Allen head bolts should be cleaned from the inside to receive the key. Most of the issues happen when the wrong size key is used or there is crud in the slot. I reach for a pick and a cleaning fluid. I also prefer the socket style keys as they allow me to pound on the key with a hammer.

I would strongly suggest that folks who switch over to hex head bolts, use a yellow/mustard marker to identify these bolts for service. [There are reasons to make the appearance of fasteners different]

Salim

 

I rounded the atf drain plug. Anyone know a good replacement?

 

You can get one at any Toyota dealer, ebay or Amazon. You have the U660E transmission if you have the 6 speed automatic like most of us. Google Toyota U660E drain plug

 

If you don't buy the OEM part [which can be cheaper at the dealer .. as there is no shipping/handling charge], measure the length of the threads. You certainly don't want it sticking in farther than it should.

Salim

 

So I spent a few hours getting acquainted with the RX this weekend. Apart from the two fluids I did allot of other little things to the RX. I finally had the time to open up the engine cover and give everything a thorough visual inspection.

The front transfer case was super easy to crank open. I did presoak everything the night before with PB blaster, so that probably helped allot. I read allot of threads and guys recommended special sockets, open end 24MM wrench, or super long extenders to get to the top fill plug but that just made it harder for me. My 1/2” drive 12” ratchet with a regular 24MM socket worked perfectly. It’s just a little bit of a pain because it’s so close to the muffler that you only get like two or three clicks at a time. All you need to do is break the seal with the socket and then just remove it by hand. The bottom drain plug is easy as can be.

The rear diff was a little bit tougher because of the surface rust in the Allen hole but I just sprayed wd40 in the hole and scraped all along the inside with a electronics flat head, and then with a paper towel, and repeated until it was fairly clean. I then lightly tapped the Allen socket into the groove with a hammer until it bottomed out and they both came right out.

I was very happy with the condition of the truck as the surface rust for a east coast car was very light. Everything underneath feels tight with no play and everything was bone dry. The only thing that was damp being the bottom of the oil pan from not being wiped by a lazy Lexus tech.

Tool wise the only thing I was missing were 6 ton jack stands. I drove the front wheels onto rhino ramps, jacked up the rear end and with my 4 ton maxed out the rear tires were almost touching the ground. The front end was slightly higher than the rear. When I was filling the fluids I jacked up the rear off the jack stands to level it out. The oils weren’t really dirty, just a very light brown. Both drain plugs did have allot of crud almost like tar all over them.