does the AWD RX300 have front & rear differential and transfer case?
 

are all these three components present on a 2001 RX300 (all-wheel-drive model)?

front differential
rear differential
transfer case

if so, do all three require fluid(or gear oil) change at the same time?
(and do they use the same fluid/gear oil?)

Thanks! :)


P.S. I know this sounds like a stupid question, but my Lexus dealer kept insisting there is no front differential on my RX300 all-wheel-drive. :(

Questions are always good to ask.

Yes, an AWD RX300 has all 3. On an FWD, the only one of the three that exists would be the front differential (which is part of the transmission).

Rear differential is shown in the picture below, takes officially 85W90 gear fluid, but I highly recommend a good synthetic 75W90 gear fluid. Best in my opinion is Royal Purple 75W90 (Pep Boys and Napa Auto Parts are best places I have seen this stuff at), though I am still running Pennzoil 75W90 Synthetic as a test

I know several here run 75W90 Mobil 1, Amsoil, all good ones as well.

This is the transfer case. Also uses 75W90 gear oil.

Again, only on an AWD will you find the transfer case and the rear differential.

And finally the front differential drain plug is shown on the left side of the photo.. This is part of the transmission unit. Although the front differential and transmission have different drain plugs, both are filled through the transmission fluid dipstick and the fluid will trickle over to the front differential side. These only take Automatic transmission fluid (ATF). Officially Toyota Type-IV fluid, though I and several others like Amsoil ATF.

You will find the front differential on both the AWD and FWD RX300s.

Lexmex:
Thank you for posting the pictures as I had a 2000 RX300 never really looked under it that hard but I remember the dealer at one service explaining to me what had to be done and the transfer case was listed.
Herbvdh
PS my son enjoys a 2006 GS300 AWD and I now have a 2006 RX400h

:uh: This may not be an issue because I haven't checked the operation of the LSD on the RX300, but the old Chevy Positracton used a series of clutches to limit the differential speed in the two axles. Putting a moly product in the diff would often reduce friction to the point that the drive would not lock up, producing some rather interesting and embarrassing results for a few 'vette drivers in our autocross club.

I'm really fuzzy on this because it was so long ago, but check to be sure that any moly-containing lube is recommended for application in your LSD.

I heard something about Chevys and the need to add a friction modifier in the gear oil, but wasn't sure about what type of Chevy. First heard about this in Mexico. A few years back, some may remember I tried to procure some synthetic gear oil south of the border, and at the time, about 2006, I was able to get some Royal Purple, but Liqui Moly and Mobil 1 were to other possibilities, but could never get them to come through. I considered Liqui Moly at the time as a possibility because I had heard of someone on the net on one of the Toyota truck forums with good experience with their 75W90 gear oil in their differentials. Luckily, I spotted that gear oil here at Napa Auto Parts, but I am still a bit away from changing it out given that I had switched out my gear oil earlier this year (to Pennzoil Synthetic 75W90).

I had mine in at the dealership 3 months ago for brakes, ATF service, Transfer Case, and Rear Diff service.

1) The reciept says ATF fluid replace (No filter change?!) I bet they didn't drop the pan!
2) Front Diff 4WD Replace 90W Gear Lube
3) Rear Diff 4WD Replace 90W Gear Lube

I think I will go back and drop the ATF pan to take a look and replace with Amsoil.

Thanks!

My Lexus dealer only has Toyota gear oil.... which the service advisor told me are non-synthetic.

Is there any real benefit in getting synthetic gear oil(such as Mobil 1)for the differential and transfer case? (assuming I change them frequently, as in once every year)

Thanks! :)

You don't say where you are located. I'd say the biggest difference between 85W90 and 75W90 gear oils would be noticed in very cold climates.

I dont know of many dealers who replace the trans filter. There is no need to drop the pan to change the oil, it has a drain plug.

i just did the pan drop and filter change over the weekend and the benefit of doing was the filter was really dirty so that would provide better flow and the magnets in the pan were really dirty as well and i doubt they would even catch anymore metal so i definitely see why one would want to do the full drop:D

and also i was able to replace another 20 - 30 percent of the fluid by dropping the pan, replacing the filter and pulling the return line from the cooler and draining another 2 quarts out there

UNOHO -

How many miles on the RX? Do you know if the filter had been changed before? Was it a paper or wire screen filter?

Thanks, I knew there was a drain plug, I was implying dropping the pan after draining to clean magnets, filter change, etc.

I'm very concerned now that in the 4 times the tranny has been serviced (Lexus dealer) in 103K miles that it has never had a filter change, or pan drop to clean magnets.

I'll do this on Friday, I'm not looking forward to what I may find...

You don't need to change them out every year. I did a test, twice, and showed the fluid was just fine after a year. You can do what you wish as far as going non-synthetic, but I personally wouldn't put anything but a synthetic in my RX300, and that's just because of my Mexican experiences. Plus, I don't know that the cost is really that much of an issue for something that minimally, might get changed out every 30K miles. Gear oil is one of those things that can last a while. I am pretty sure that from the time I got my RX300 used at about 42K until about 100K or so when I first changed out the gear oils, Lexus never did this, but the vehicle still worked okay. But after changing out the gear oil at that point, I did notice an improvement in 2nd to 3rd gear (which I felt personally in the last 75 meters of so of 1/4 mile racing).

i have 212k miles on it, 99 awd btw, have no clue if it had been done before, i bought the car at 150-160k miles and just did it for the first time, the one that was in there was a wire screen, new one was paper or cloth, didnt look that closely, same exact shape as the one pictured in tunedrx300's diy, this is my first car that i actually started doin all the work on it myself and no place i took it would do a tranny flush cause they didnt have the right atf, then i found you guys :woot: and enlisted my gf to help me work on my car myself:D

Thanks, that's good information. Maybe I'll wait for the 100,000 mi. point before dropping my transmission pan. (That's maybe 3 more years). Just for curiosity: (1) what was the color of the transmission fluid when you first drained it? (2) how would you describe the material on the mesh screen when you replaced it (e.g., grey powder, metal shavings, etc.)? Do you think you could have just cleaned the mesh screen?

the old fluid was kind of a chocolate brown, and smelled of burnt...ness lol, just smelled burnt, you might be able to clean out the wire screen but honestly i would just go buy the filter replacement kit, it was just a little over 20 bucks for the best one offered by advance auto parts, they did have to order it for me from another store which took several days so make sure you order it at least a few days before you plan do drop it, also just so you are aware, other than OEM atf from the stealership i couldnt find anyone that carried atf for our cars around here AND I LIVE 5 MIN FROM THE DC BELTWAY!! so i ordered mobil atf 3309 from here: http://avlube.com/mobilatf3309.html

just follow the DIY guide and you shouldnt have any problems at all, one thing he doesnt mention in the DIY and im not even entirely sure its necessary but my gfs dad (who was supervising) instructed me to put a little bit of some sealant under the gasket, mainly to hold it in place when i put the pan back up but also to prevent leaks and i also had to really really clean off sealant from the pan and block that the pan connects to to make sure i got a good seal, im guessing mine had been dropped before and the guys that put it on before used A LOT, the hardest part was just getting the pan to drop after all the bolt were taken out, had to use a small crowbar and screwdrivers whaomp whaomp waaaaaaaaaa, but everything is good to go now, shifts better and everything, im pleased:D

oh yea, material on the magnets (didnt really look at the screen too much) was more like wet powder with a few tiny tiny metal slivers but mainly wet metal powder

Probably nothing if your not having any symptoms,Hopefully you will just find normal wear.

does the RX300 take GL-4 or GL-5 gear oil? (or is no difference between the two?)

thanks! :)

GL-5 (this can be verified in the service manual, too).

just out of curiosity what is that rating? like viscosity or.....:uh:

It's an 85W90 for the RX300, but don't concern yourself with that, a good 75W90 synthetic is the way to go.

cool deal man, thats next on my list, i swear ever since i got on this site my car has never run better, thanks guys:woot:

I decided it was too messy for me...

so I brought my Rx300 to the dealer, after the service advisor quoted me $95 to change both the rear diff fluid and the transfer case fluid. (plus sales tax of a few dollars)

while I was standing there waiting for the service advisor to write up the repair order, I noticed that the parts dept had the Mobil 1 synthetic gear 75w90 oil on the shelves(next to the Mobil 1 synthetic engine oils). I asked him how much more it is to get the synthetic, instead of whatever Toyota gear oil they used. The advisor said that they're not allowed to use synthetic gear oil on the RX(old or the new ones). The synthetic is only to be used on the ES/GS/IS/LS, as well as the LX. ???? I became confused... it was the first time that a Lexus dealer turned down my offer to pay more money for synthetic stuff.... :sad:

He said that if I had a GS, for example, it would cost an extra $25 if I want to use the synthetic gear oil. (I've dealt with this same service advisor for almost 8 years)

can anybody tell me why my Lexus dealer didn't want my money? I thought synthetic was always better than conventional gear oil, no?

Just a guess, but the early RX300's had limited slip differentials. Lexus probably told dealers not to put anything but the OE oil in them worried about the LSD additive (or lack of). The newer models are probably not using LSD so it's not an issue. The dealer probably never changed their rules for the RX not knowing what the reason was in the first place.

If there were real issues with synthetics in these cars they would be known by now. IMO

Go somewhere else or DIY, don't buy into that. I haven't had a single issue nor any else I have know with using the 75W90 synthetic oil. Granted 75W90 is not 85W90, but works just the same. Synthetic oil will be the only thing going into my RX300.

I haven't heard of any such TSB for the transfer case. What I do know of is that some people (myself included) had reported having issues with leaking transfer cases at the seals. However, this was BEFORE anyone had made any switchover from anything but the OEM 85W90 oil. So, why would Lexus want to continue down the same road?

When I did my transmission work last year, my uncle switched out the transfer case seals at that time, but still working on Pennzoil Synthetic 75W90 and not a leak since.

Unless I am missing something here, I don't remember anyone who has used 75W90 synthetic (Mobil 1, Amsoil, Royal Purple, I think a few went Redline) who have had leaks). I also recall a few people here over the years even took bottles of M1 75W90 to the dealer and didn't run into any issue.

no, it's not the transfer case.

The service advisor happily allowed me to pay extra and use their Mobil 1 Synthetic gear oil for the transfer case on my RX300 AWD.

It's only the rear differential that they refused to let me choose the Mobil 1 synthetic oil. I asked the service advisor if he made a mistake, but his boss, the service manager, came out and told me the same thing....

In fact, I had my AWD GS sedan serviced there three ago. The same service advisor allowed me to choose the Mobil 1 synthetic gears for both the transfer case and rear diff.

Actually carguy,the limited slip at least in 01,was an option.Unfortunately for me,mine doesn`t have it.:cry:

I'm looking at the original 2001 Lexus RX300 brochure in my hand....
in the list of options(on page 45), limited slip differential was not
listed. :(

(edit: just finished looking through the entire brochre, it doesn't
say anything about LSD at all.... if anyone has a '99/'00 borchure,
can you please check to see if LSD is mentioned anywhere? thanks!)

I'm not the expert, but I think the LSD was only on the 99 or maybe 99 & 00. Once they put the VSC on them the used the computer to modulate the brakes to simulate a LSD. I have seen internet advertising saying that it was an option on the later cars but I think it is incorrect.

If these are correct it looks like they dropped it in 2000.

http://www.lexus.com/contact/pdf/1999/1999RXspecs.pdf

http://www.lexus.com/contact/pdf/2000/2000RXspecs.pdf

http://www.lexus.com/contact/pdf/2001/2001RXspecs.pdf

http://www.lexus.com/contact/pdf/2002/2002RXspecs.pdf

http://www.lexus.com/contact/pdf/2003/2003RXspecs.pdf

Interesting,I stand corrected.

Hi, ok I've read alot of these rear, front differential and transfer case threads. Too much that now I'm a bit confused. My question is... is there only one "transfer case" then? I know that there is one rear differential and one front differential. But am confused about the transfer case. I'm thinking there is only one transfer case that is in the front? That is connected to the front differential which is connected to the tranny?

Sorry if its a lame question, just that I just recently purchased a rx300 with no service records, so I plan on doing a tune up; oil change; front, rear and transfer(s) case flush; coolant flush, transmission flush, engine air filter change, cabin air filter change, also if I get to it the "D" light bulb and "ECT/SNOW" light bulb in instrument cluster change.

You got it right. :thumbup:

LSD Option
 

I'm sure you are right. I have a 2000 that I ordered new and I selected LSD, in fact I selected every option available at the time. The VSC would make the LSD redundant. Frankly I would rather have VSC because my wife drives it. She has already wrecked it once in snowy conditions. LSD helps you get moving(two wheels instead of one), but once moving having the rear end basically locked on a slippery surface is not a good thing. With a conventional diff one wheel is likely to always stay in direct rotational contact while the other spins. This can actually help with straight line stability. VSC tries to ensure that all wheels stay in direct rotational contact. I'm basically convinced that if I hadn't checked the LSD box back in 2000 that my wife would have never ended up in the ditch. Some winter tires would have also helped.

I have an appointment to have my diff fluids changed for the first time(120K). As for the Tranny it has been changed once but if I remember correctly it has a very long service schedule. In fact I need to check but I don't remember a recommendation for it.

whoa arch, 120k and the first time changing the fluids in the transfer case,and rear diff.? I would absolutely love to see what comes outa their. :eek3: