Domenico Nelli Posted August 9, 2011 Share Posted August 9, 2011 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 Quote Link to comment Share on other sites More sharing options...
lenore Posted August 9, 2011 Share Posted August 9, 2011 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 Quote Link to comment Share on other sites More sharing options...
Domenico Nelli Posted August 9, 2011 Author Share Posted August 9, 2011 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. Quote Link to comment Share on other sites More sharing options...
lenore Posted August 9, 2011 Share Posted August 9, 2011 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... Quote Link to comment Share on other sites More sharing options...
Domenico Nelli Posted August 9, 2011 Author Share Posted August 9, 2011 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. :) Quote Link to comment Share on other sites More sharing options...
Domenico Nelli Posted August 10, 2011 Author Share Posted August 10, 2011 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 Quote Link to comment Share on other sites More sharing options...
lenore Posted August 10, 2011 Share Posted August 10, 2011 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.... Quote Link to comment Share on other sites More sharing options...
Domenico Nelli Posted August 10, 2011 Author Share Posted August 10, 2011 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. Quote Link to comment Share on other sites More sharing options...
lenore Posted August 10, 2011 Share Posted August 10, 2011 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.... Quote Link to comment Share on other sites More sharing options...
Domenico Nelli Posted August 10, 2011 Author Share Posted August 10, 2011 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 Quote Link to comment Share on other sites More sharing options...
lenore Posted August 10, 2011 Share Posted August 10, 2011 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... Quote Link to comment Share on other sites More sharing options...
galtom Posted July 10, 2014 Share Posted July 10, 2014 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? Quote Link to comment Share on other sites More sharing options...
lenore Posted July 10, 2014 Share Posted July 10, 2014 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.... Quote Link to comment Share on other sites More sharing options...
galtom Posted July 10, 2014 Share Posted July 10, 2014 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? Quote Link to comment Share on other sites More sharing options...
lenore Posted July 10, 2014 Share Posted July 10, 2014 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. Quote Link to comment Share on other sites More sharing options...
galtom Posted July 10, 2014 Share Posted July 10, 2014 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)? :-) Quote Link to comment Share on other sites More sharing options...
lenore Posted July 10, 2014 Share Posted July 10, 2014 The fluid in the front and rear differential changed with a good synthetic will easily last 75k miles... Quote Link to comment Share on other sites More sharing options...
galtom Posted July 10, 2014 Share Posted July 10, 2014 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? Quote Link to comment Share on other sites More sharing options...
lenore Posted July 10, 2014 Share Posted July 10, 2014 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. Quote Link to comment Share on other sites More sharing options...
galtom Posted July 10, 2014 Share Posted July 10, 2014 Thanks! Any synthetic.... or something specific? Quote Link to comment Share on other sites More sharing options...
RobbieRob Posted September 26, 2020 Share Posted September 26, 2020 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. Quote Link to comment Share on other sites More sharing options...
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