OIL FOR LSD EQUIPPED REAR DIFFERENTIAL RX300

I have a 99 RX300 AWD with optional Limited Slip Differential at the back. I am the 2nd owner, just bought it last year @90K miles. So far so good.
Current mileage is 102000 Miles. timing belt hasn't been replaced yet.

I just went under the car, seems to me the front differential, transmission, transfercase, rear LSD differential have never been opened at all.
There is no scratch/mark at all, and the green colored marking are still at these plugs.


What kind of oil, should I use for the rear LSD differential?(This is RX300 with optional Limited slip differential, I belief LSD use different oil rather than GL5-90W. Does Mobil 1, 75W-90 is acceptable)


Also, can someone reassure me that front differential oil can be filled thru transmission dipstick?

I saw transmission drain plug and front differential drain plug, but I did not find the front differential oil filler.


I just don't want to oopen the front diff plug and then unable to fill it back with Toyota T-IV oil.


Appreciate any advise
Email: mek88@yahoo.com

 

Hello Mek

I also have a ‘99RX300 and have both shop manuals: there is no mention of special gear fluid for LSD or not! It looks like they take 75w-90 GL-5. Same as the center differential. The center and the rear take a gasket for the filler (top) and for the drain (bottom) plug. The transfer case has a drain plug but no filler; it gets its fluid from the transmission. There is a total of 6 gasket to request at the Toyota/Lexus part counter. Personnaly, I drain my transmission every year (because I tow a tent trailer) and the diffs every two years.

Make sure you measure the transmission fluid when you drain it, in order to prevent under/overfilling.

As far as the LSD, I believe that Lexus used a mechanical (kind of Torsen) differential instead of a “wet clutch pack”. My old Nissan 240SX required additional conditioner with the gear oil, because of its open clutch pack LSD.

How do you know that you have the optional rear LSD??? Any marking on the case??? I purchased my ’99 used and I would like to figure out if it has a LSD or not. Even if we had lots of snow, the AWD system works too good: I cannot see if one rear wheel slips or not…

Good luck

 

Limited Slip Diff ?

that would be the difference between the ...10 and the ...20.

 

Hello EDERNY

I saw that too in my shop manual... the C clip is inside the differential case for LSD and the C clip is outside the case for the non-LSD (or vice-versa). There is no way I will disassemble the rear end just for curiosity... my wife will kill me for sure...

I am looking for color/alpha-numeric marking, cooling fins, anything but disassembly. I know that I can call Lexus Canada trying to find out from the VIN or the options sale slip. But I will look for that 48020 stock number.

I only wished that there were a simple way to find out.

Thanks for your help

JB

 

Thanks for the advises folks.

When I bought my 99 RX300AWD, the previous owner gave me the msrp sticker as well, and the LSD is listed there as an option for around $350.00

The back cover of the rear differential is chromed, how is yours?