2000 Awd Rx300 Transfer Case & Rear Diff Fluid Change

[Domenico Nelli]

I just preformed a flush of my tranny fluid. I used 8.5 quarts. I measured every bit that came out and added the same amount back in.

I now would like to change the transfer case fluid/oil which i suppose it the front differential? I believe that it isn't part of the tranny fluid circuit as the book mentions gear lube for there and the rear differential. Is this true? Can I get a picture of where the fill for the transfer case is on my AWD vehicle? I know to open it before I drain it in the event that I can't get it opened. Also, any procedural steps for tis service would be greatly appreciated....and if you could include pictures that would be great too!

Thanks for your help.

Dom

[lenore]

Here is a great one from Club Lexus:

http://www.clublexus.com/forums/rx-first-generation/384943-does-the-awd-rx300-have-front-and-rear-differential-and-transfer-case.html

[Domenico Nelli]

Thx Lenore....so riddle me this....the front diff is part of the tranny circuit and uses Type 4 fluid? The transfer case uses gear oil as does the rear diff...correct?

thx again.

[lenore]

The front differential shares the tranny fluid...The front transfer case uses gear oil as well as the rear differential...I put in full synthetic on mine. The front and rear each take a full quart...So 2 quarts should do you. remember remove the fill plug first, then the drain plug in case you cant get them undone. You will need a pump to put the fluid in. they sell them at any parts store...

[Domenico Nelli]

The front differential shares the tranny fluid...The front transfer case uses gear oil as well as the rear differential...I put in full synthetic on mine. The front and rear each take a full quart...So 2 quarts should do you. remember remove the fill plug first, then the drain plug in case you cant get them undone. You will need a pump to put the fluid in. they sell them at any parts store...

Cool, thanks for the heads up on the pump, I don't have one. I did read to first loosen the fill plug prior to dumping the gear oil. :)

[Domenico Nelli]

The front differential shares the tranny fluid...The front transfer case uses gear oil as well as the rear differential...I put in full synthetic on mine. The front and rear each take a full quart...So 2 quarts should do you. remember remove the fill plug first, then the drain plug in case you cant get them undone. You will need a pump to put the fluid in. they sell them at any parts store...

Hey Lenore...one more question please. I was able to change the front transfer case gear oil though, since I had the RX's front tires on ramps, I could only get so much gear oil in before it started running back out the fill hole. So I capped the fill, back it off of the ramps and then backed the RX's rear tires up onto the ramps to finish added that last bit of the quart.

My question is, where the heck is the fill for the rear pumpkin? I found the drain of course, and saw three hex headed bolts aft of the pumpkin that are accessed through the frame. I presume that one or all of those three are the fill? Any more help you could lend would be tremendously appreciated.

Thank you,

Domenico

[lenore]

Look closely on frame 2 of the write up...the plug is next to the exhaust pipe and the plug looks like the drain plug....

[Domenico Nelli]

Look closely on frame 2 of the write up...the plug is next to the exhaust pipe and the plug looks like the drain plug....

Kewl thanks! I did another google search and found some pictures of it. passenger side of the pumpkin, i believe that maybe the axle was impeding me from seeing it last night.

[lenore]

One other note: some RX300 had limited slip differential....mine did, so I made sure that the gear lube that I used stated it was good for limited slip axle....

[Domenico Nelli]

One other note: some RX300 had limited slip differential....mine did, so I made sure that the gear lube that I used stated it was good for limited slip axle....

How do I determine whether or not mine is limited slip? I purchased Valvoline 75W/90 for limited slip for both the transfer case and rear diff. Also, I noticed that my driver's side rear axle shaft seal at the diff seems to be leaking. Have you ever done one of those?

Thx again

[lenore]

I believe there is a way to figure out the limited slip by jacking the rear up and turning the wheels, but I cant remember the procedure...As long as the fluid says it is good for limited slip you are good to go....As for the seal, sorry cant say I have...Google it, maybe there is some info on the seal...it would envolve removing the drive axle from the differential to replace that seal...

[galtom]

Can someone clear that up?

I got 2003 (1st gen) US RX300.

In regard on differential oil change I have been advised following:

Polish Lexus dealer: Oil SAE 80W90 changed every 30kkm (approx: 18.600 miles)

Lexus US at Facebook: The differential fluid should be inspected every 24 months and changed if dirty with Genuine Toyota T-IV Fluid

Lexus NY dealer: 80-90 gear oil and you change it every 3 years or 30,000 miles which ever one comes first.

You (on the top):The front differential shares the tranny fluid...The front transfer case uses gear oil as well as the rear differential...

And this link: http://www.clublexus.com/forums/rx-first-generation/384943-does-the-awd-rx300-have-front-and-rear-differential-and-transfer-case.html

states:

Rear differential is shown in the picture below, takes officially 85W90 gear fluid [...] This is the transfer case. Also uses 75W90 gear oil.

Can someone clear this up, please?

[lenore]

The transfer case and transmission share the same fluid, They are located on the left side of the vehicle. The differential is located more to the center of the vehicle up front and uses 80-90wt. Then there is a driveshaft from this differential going to the Back of the car in All Wheel Drive RX300's which goes to the real differential which also uses 80-90 wt. Front wheel drive only vehicles do not have the differentials. As for changes, I personally suggest drain and fill on the Transmission with Toyota Type IV or Mobil 1 Synthetic transmission fluid. As for the differential, they each take 1 liter of 80-90 fluid which quite frankly should be fine changing every two years....

[galtom]

Ok.. let me make sure I get this right :-)

Transfer case is the thing that puts front wheels in motion?

If I just had transmission oil changed, that means also oil in transfer box is new. They both use ATM transmission oil - Toyota T-IV.

Now differential in the centre (that uses 80W90 oil) - this one is responsible for transfer of power between axles and this is the one I want to change oil in - not front differential as it is existing in RX300.

And on the rear axle we have rear differential (same 80w90 oil) that transfers power to rear wheels.

Is this correct?

[lenore]

Yes, but note one thing, there is an additional drain plug on the transfer case which can drain an additional small amount of the transmission fluid. What ever you do, do not do a flush on this transmission, drain and fill only. approximately 4.2 quarts. Also note the transfer case and transmission are filled by filling the transmission thru the dip stick tube in the engine compartment. Read my post with link #2 above in this thread, the pictures are very good.

[galtom]

This is exactly what has just been done. With one exception - we (my friend was doing the whole thing) did not replace transmission filter this time.

However I have to use services of a garage now and I want to make sure they will do this thing right.

So... now I have to be asking for change of oil in central and rear diff, not front one (as I was)? :-)

[lenore]

The fluid in the front and rear differential changed with a good synthetic will easily last 75k miles...

[galtom]

The fluid in the front and rear differential changed with a good synthetic will easily last 75k miles...

What front differential (look up)? Do you mean central diff?

And what synthetic would you use instead of 80W90?

....and your opinion is based on what? Why is not Lexus recommending synthetic oil?

[lenore]

I previously owned a 1999 RX300 for 12 years and 188k miles before I sold it. never had any issues with synthetic and it generally is recognized as superior.

[galtom]

Thanks! Any synthetic.... or something specific?

[RobbieRob]

Lenore's 2011 post is correct, his 2014 post is completely backwards. Front diff shares trans fluid with the transmission and uses the same hex head socket to drain. The transfer case is center behind the transmission and has both plugs very close to each other. Original equipment fill plug will say use 80-90(or 85-90) on the plug.