NyCrAzY

Did my own oil change today for the first time thanks to those helpful DIY's lovely Lexmex provided *feels accomplished*

Next target in the upcoming week is a transmission drain and fill.

Seems like 90% of the forum says to only drain & fill and not flush.

Questions -

1.) The front diff and transmission fluid shares the same drain, right?

2.) Looks like the transfer case is next to the transmission fluid. They use the same ATF fluid right? And does it fill through the transmission dipstick?

3.) I wont get all the fluid out so how many quarts am I expecting to get out?

4.) It wont be bad to mix the existing atf with new ones?

Sorry about the noob questions. I'd rather be safe than sorry.

carguy07

1) The front diff and tranny have their own drain plugs but share the same tranny fluid, filled though the dip stick.

2) The transfer case takes gear oil and is filled through a filler plug.

3) Tranny/diff take 4 1/4 quarts for me.

4) Mixing old with new is not a bad thing, but it takes about 3 or 4 drain and fills to really clean it up. That's why many people will pull the hose from the tranny cooler and pump out the system before refilling (if you pump it out you will need more than 4 1/4 quarts).

hypervish

I think carguy07 covered it all, but just one thing to note, be sure to use Toyota Type-IV compatible fluid. Be sure whatever transmission fluid you use has spec'd Toyota Type-IV on the back of the bottle.

I use Castrol Transmax Multi-Vehicle Import Fluid, it works great and it's a synthetic blend. I needed a little over 4 quarts when I changed the fluid out last week. I didn't open the differential drain plug though, as I couldn't find a socket that would clear the exhaust.

NyCrAzY

Thank you guy(s) for the generous answers! Seems like the drain & fill is an easier job than an oil change.

Anyways -

1.) When I drain out the atf, I measure how much I got out of it and put that same amount back in with the fresh atf. Am I correct?

2.) Is there a DIY on targeting the drain plug for the front diff? And to fill the front diff, it goes through the same transmission dipstick for the transmission fluid?

3.) How do I read the red transmission dipstick? Its different than the oils.

Once again, thank you.

Kind regards.

hypervish

You're Welcome.

1) Yes, it's best to measure how much came out and put that amount of fresh fluid back in.

2) https://www.clublexus.com/forums/1933460-post3.html < that's a picture of the drain plug for the front differential, it's mislabeled as the transfer case plug. The front differential get's filled through the transmission dipstick as well. It shares fluid with the transmission.

3) Check the transmission fluid once the car is warmed up. Shift through all gears, P,R,N... and then keep the car running while checking the fluid. It should be up to the "hot" line.

Here's another thread regarding the transmission and front differential by Lexmex. https://www.clublexus.com/forums/rx-...ferential.html

carguy07

Personally I think measuring the old fluid is not needed unless you have no idea how much to put back. Pour in 4 quarts and a splash from one more and you will be right where you need to be (at least on my 2001).

blueridge

Not sure if you're planning on doing this or not. I'd strongly recommend changing the transmission plug gasket out and and transfer case plug gasket. They are not like the oil pan gaskets that can be reused. I tried and show drips occurred.

NyCrAzY

OH! I was right the whole time then. Somebody should edit that post and change it to front differential.

All makes sense now, thanks a bunch, bud!

NyCrAzY

Sounds fair enough. Just gotta learn how to read the dipstick as well and I should be good to go!

Interesting. Gotta look into that. Thanks for the fyi, I would of never thought the atf/front diff. drain plug would need one.

blueridge

Transmission pan and Front Diff drain plug gasket Toyota part# 90430-18008
Rear Diff and Transfer case (gear oil) drain plug gasket Toyota part# 12157-10010

They're crimp style gaskets unlike the oil plug ones. Same goes for the rear diff. I tried to reuse the ATF plug gasket and found a small puddle under it in the morning. One shot deal once tightened down.

Aprazur

I'm a old retired trans mechanic. I'd recommend that you get all of the old grimy oil out by disconnecting the trans cooler return hose and pumping out the old oil into a bucket via a clear plastic (Lowe's) hose. As you add new fluid until the fluid color changes from poop brown to clean red.

Use what new oil that you want just make sure its compatible with IV. I bought a case (12QTs) of IV at the Toyota dealer for about $5 a quart. I used it to flush the old oil out. I then pulled the pan and cleaned & replaced my metal screen. I added 10+ quarts of Amsoil ($10.75qt) and never looked back about 10K ago. Per my trans gauge, I'm running 30 degrees cooler with Amsoil than IV in the trans. Heat is the Tran's enemy.

Just sayin.... There's lot's better newer tech oil now available than Toyota IV for our Trans.

dtewing

I wanted to give everyone and update on this old thread in case they look through it like I did.

The OE Part number for the crush washer (gasket) for the transmission plug (and transfer case) is:

90430-18008

This is a Toyota # but it is the same for RX300 series. Cost at dealership ~$1.25.

glenpointe

I think you have transfer case and front differential backward. Transfer case part and trans use the same trans fluid. Differential uses gear oil

salimshah

You are correct!.

The share the same fill point and have a different drain point. The fluid is shared and the second drain point gets few more ounces out.

Salim