RX - 1st Gen (1999-2003) Discussion topics related to the 1999 -2003 RX300 models

What type of LSD in a 99 RX300?

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Old 07-25-12, 06:26 AM
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sktn77a
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Default What type of LSD in a 99 RX300?

OK, the local dealers haven't got a clue - half of them say I have a clutch type LSD and the rest say I have a torsen type (I definitely have an LSD - it's on the window sticker). My understanding is that it is a clutch type but the gear oil is different for the two so I want to be sure.

Lexus Gurus........ which witch is which???

Old 07-25-12, 06:36 AM
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thomas1
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you know I just added fluid that met Lexus/Toyota specs....if it says for Limited slip you should be good. I used Royal purple and Mobil 1 limited slip gear oil and had no problems for the ownership of my Lexus RX300 till 183K miles when I sold it.
Old 07-25-12, 07:16 AM
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reisjdmd
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holy cow, i thought you were talking about drugs, whcih would explain why these cars have some of the weird problems they have.
Old 07-25-12, 07:47 AM
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carguy07
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It's a Torsen: http://en.wikipedia.org/wiki/Torsen

Like thomas1 said just use gear oil that says it's good for LSD like Mobil 1, Royal Purple etc, and you are good to go.
Old 07-25-12, 07:54 AM
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DaveGS4
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He's correct that the two different types of LSD (clutch, torsen) take different fluids. The clutch type uses a friction modifier which sometimes comes built into the fluid or can be put in as an additive to the normal gear oil.

I believe that I've actually bought a friction modifier additive from the Lexus dealer parts counter meant for the RX in the past. This was 10 years ago though.
Old 07-25-12, 01:24 PM
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PaulDaisy
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Torsen it is: http://www.google.com/url?sa=t&rct=j...BDRvJIaQymZnug
...and I read elsewhere that starting in 2001, the real LSD was eliminated and replaced by electronic traction control, right?

Last edited by PaulDaisy; 07-25-12 at 01:31 PM.
Old 07-25-12, 02:18 PM
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sktn77a
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Correct. They discontinued the LSD in 2001 when the added traction control (making the LSD redundant). It certainly appears to be a Torsen LSD in the 1999 and 2000 RX300. I wonder where I saw the "requirement" for the friction enhancing additive (which is used in clutch-type LSDs)?
Old 07-25-12, 03:04 PM
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PaulDaisy
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I'm not sure I'd agree if the traction control is redundant unless, like the Cherokees with the Trail package, they have something going on with the rear and front differentials. For that, the rear diff on my 2001 looks way too small and unsophisticated. So I conclude, there is no inter-wheel traction control, only inter-axle. Which is far from the same as a LSD.
All of this is quite irrelevant from the off road perspective though as probably very few people would seriourly use their Lexus in the conditions that would benefit from LSD. And for city snow and slick, the inter-axle torque distribution is probably just fine.
Old 07-25-12, 04:11 PM
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salimshah
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It is a long story...

The AWD design in the early models was a bust due to viscous fluid coupling. In those days Mercedes was the only competition in Lux-sport-utility. They made special ramps with rollers and demoed that RX has a bad design. [RX with FWD with traction control could climb, but they did not demo that ].

I am sure that each design has a weak point and every system has a limitation. Fortunately, people dont push their vehicle to the limit.

I miss the long heated posts by wwest .. maybe they reside some where on the net ,,, but I am talking about things that happened about 12 years.

Salim

Last edited by salimshah; 07-25-12 at 04:15 PM.
Old 07-25-12, 06:04 PM
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hypervish
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Originally Posted by salimshah
It is a long story...

The AWD design in the early models was a bust due to viscous fluid coupling. In those days Mercedes was the only competition in Lux-sport-utility. They made special ramps with rollers and demoed that RX has a bad design. [RX with FWD with traction control could climb, but they did not demo that ].

I am sure that each design has a weak point and every system has a limitation. Fortunately, people dont push their vehicle to the limit.

I miss the long heated posts by wwest .. maybe they reside some where on the net ,,, but I am talking about things that happened about 12 years.

Salim
He's still very active on the Edmunds forum. Let's just say I'm glad he isn't hanging around CL anymore.
Old 07-26-12, 03:01 AM
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Lexmex
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wwest was the guy who figured out the daytime driving lights fix by pulling out the cable underneath the battery tray
Old 07-26-12, 06:31 AM
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thomas1
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Heck I miss his post, they were very detailed. (wwest) and of course enlightening.
Old 07-26-12, 07:10 AM
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hypervish
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Really? I remember reading his posts, and they all sounded very negative, although it sounded as though he knew what he was talking about for sure! He was very informative. But, mind you, I wasn't a member of the forum at that time ; I only read the posts, and maybe I'm remembering them wrong.
Old 07-29-12, 11:02 PM
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salimshah
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One of the things we request that when a discussion stops being meaningful, or posts keep repeating the same point, then it is better to stop.

Salim
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