Retrofitting Mechanical Limited Slip Differential (LSD) 08-09 ISF
09-04-09, 12:14 AM
#31
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Maybe, i should make more friends in Japan, owing that I Go there really often because i'm the vice chairman of the Kyokushin Karate Committee in Malaysia. Japan beckons... for more than JUST karate now lol. When i do go, ill give you guys the heads up and see if i can get stuff for you!
JoeZ, that looks awesome. There definitely is hope then!
JoeZ, that looks awesome. There definitely is hope then!
When you go, let me know...
I know exactly where to send you, to get technical information regarding the swaps that have taken place.
Joe Z
09-04-09, 11:39 AM
#32
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I speak conversational japanese. I can more or less understand 
But i have many japanese friends and translators. When i do go ill give you the heads up.
Hmm.. actually.. i can tell you exactly when im going. Ill be going on the 1st of November. All Japan Karate Open Championships take place on the 3rd..
Now theres a thought JoeZ. And once i get the info ill pass it on to you buddy.
But i have many japanese friends and translators. When i do go ill give you the heads up.Hmm.. actually.. i can tell you exactly when im going. Ill be going on the 1st of November. All Japan Karate Open Championships take place on the 3rd..
Now theres a thought JoeZ. And once i get the info ill pass it on to you buddy.
09-04-09, 02:11 PM
#33
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Keep in mind these are both clutch type LSDs so they're going to chatter. The LSD in the 2010 IS-F is a Torsen gear driven unit. Each has their advantages and disadvantages, but for a daily driver, you'll appreciate the Torsen's quietness and smooth operation. Clutch type units are not nearly so street friendly but work incredibly well at the track and have simpler tuning.
09-04-09, 02:32 PM
#34
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Keep in mind these are both clutch type LSDs so they're going to chatter. The LSD in the 2010 IS-F is a Torsen gear driven unit. Each has their advantages and disadvantages, but for a daily driver, you'll appreciate the Torsen's quietness and smooth operation. Clutch type units are not nearly so street friendly but work incredibly well at the track and have simpler tuning.
I remember what my IS300 Torsen LSD sounded like when I got it serviced at Lexus and they forgot to add the additive to the 80w90 reg diff fluid..
It was a "Chatter box" for a few days until I was able to have it corrected.
Do the IS300 Torsen units have gears or clutch internals??
Joe Z
09-04-09, 02:34 PM
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I honestly don't think the time, money and effort put into retrofitting the mechanical LSD into the previous IS F would be worth it unless you're going to be tracking this beast to all hell and back. A true mechanical LSD does not have a logical place in a majority of real world applications, even if these is some excitement to be had on public roads.
09-04-09, 02:39 PM
#36
I honestly don't think the time, money and effort put into retrofitting the mechanical LSD into the previous IS F would be worth it unless you're going to be tracking this beast to all hell and back. A true mechanical LSD does not have a logical place in a majority of real world applications, even if these is some excitement to be had on public roads.
But if you're going to track it, it is a no-brainer.
09-05-09, 03:35 PM
#37
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Now there's a tid bit I didn't catch onto the other day......
I remember what my IS300 Torsen LSD sounded like when I got it serviced at Lexus and they forgot to add the additive to the 80w90 reg diff fluid..
It was a "Chatter box" for a few days until I was able to have it corrected.
Do the IS300 Torsen units have gears or clutch internals??
Joe Z
I remember what my IS300 Torsen LSD sounded like when I got it serviced at Lexus and they forgot to add the additive to the 80w90 reg diff fluid..
It was a "Chatter box" for a few days until I was able to have it corrected.
Do the IS300 Torsen units have gears or clutch internals??
Joe Z
09-05-09, 03:47 PM
#38
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Torsen is gear type. It should never chatter with any kind of gear oil and it should not require any type of additive. Chatter is from the clutches sticking and slipping. Gears don't do that. It's extremely odd your IS300 would chatter ever. Somebody at Lexus did something really wrong.
Can't chatter also sometimes be associated with faulty coilpacks?
09-05-09, 04:38 PM
#39
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No. LSD chatter only happens while turning. Faulty coilpacks cause break up not chatter.
09-05-09, 11:34 PM
#40
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Torsen is gear type. It should never chatter with any kind of gear oil and it should not require any type of additive. Chatter is from the clutches sticking and slipping. Gears don't do that. It's extremely odd your IS300 would chatter ever. Somebody at Lexus did something really wrong.
So it got a tad bit noisey on up hills and slow starts, with out it.
We used this product..
Originally Posted by CRC Industries
EQUA-TORQUE is a special friction modifier concentrate designed to be added to the differential. Reduces the coefficient of friction, therefore improving the performance of limited - slip differentials.
I solved the additive nonsense by just using Full Synthetic LSD Gear Oil going forward....
Joe Z
Last edited by Joe Z; 09-05-09 at 11:46 PM.
09-06-09, 07:38 AM
#41
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A little off-topic, but here's the deal with friction modifiers. Red Line has some great info on their site, but essentially they sell two different kinds of differential oils - those with friction modifiers and those without. Here's the scoop on the "without":
Here's the regular 75w-90:
* Most popular Red Line gear oil, with thousands of applications for passenger cars, light trucks, and racing vehicles
* This product is not designed for use in most manual transmissions or tranaxles, since the extreme slipperiness may cause synchronizer mesh issues that lead to shifting problems
* Recommended for API GL-5, GL-6, MT-1, MIL-L-2105E, and SAE J2360
Finally, here's their Friction Modifier:
So it sounds like Lexus put gearbox oil in your differential, then corrected the problem by adding friction modifier. Had they put the correct oil in from jump, you would not have noticed anything. FWIW, I tried running NS in my Supra's Torsen and bought a bottle of friction modifier to "tune" it. Needless to say, the differential didn't care one way or another and never chattered even with pure NS in it. Since it was a complete waste of time (and money) I have since only bought the standard gear oil and called it good.
75W90 NS GL-5 Gear Oil
* Designed for transmissions and transaxles - helps to slow synchros for easier shifting across a broad temperature range
* Popular in Ferrari, Porsche and Subaru transaxles
* Musclecar applications like Ford Top Loader, Borg-Warner T-10 and Super T-10, and Muncie transmissions
* Contains extreme pressure additives like our 75W90 GL-5 oil, but lacks friction modifiers to balance slipperiness
* Improved copper corrosion protection to prolong synchro life
* Helps with lock-up on weak limited-slip differentials-compatible with Red Line Limited Slip Friction Modifier for tuning slippage
* Also used with clutch-type LSDs in racing for maximum lock up
* Recommended for API GL-5, GL-6, MT-1, MIL-L-2105E and SAE J2360
* Designed for transmissions and transaxles - helps to slow synchros for easier shifting across a broad temperature range
* Popular in Ferrari, Porsche and Subaru transaxles
* Musclecar applications like Ford Top Loader, Borg-Warner T-10 and Super T-10, and Muncie transmissions
* Contains extreme pressure additives like our 75W90 GL-5 oil, but lacks friction modifiers to balance slipperiness
* Improved copper corrosion protection to prolong synchro life
* Helps with lock-up on weak limited-slip differentials-compatible with Red Line Limited Slip Friction Modifier for tuning slippage
* Also used with clutch-type LSDs in racing for maximum lock up
* Recommended for API GL-5, GL-6, MT-1, MIL-L-2105E and SAE J2360
75W90 GL-5 Gear Oil
* Most popular Red Line gear oil, with thousands of applications for passenger cars, light trucks, and racing vehicles
* This product is not designed for use in most manual transmissions or tranaxles, since the extreme slipperiness may cause synchronizer mesh issues that lead to shifting problems
* Recommended for API GL-5, GL-6, MT-1, MIL-L-2105E, and SAE J2360
Limited Slip Friction Modifier
* Compatible with both petroleum and synthetic gear oils
* Reduces break-in temps as much as 50°F
* Add 1oz at a time to clutch-type limited slip or posi-traction units to eliminate chatter
* Compatible with both petroleum and synthetic gear oils
* Reduces break-in temps as much as 50°F
* Add 1oz at a time to clutch-type limited slip or posi-traction units to eliminate chatter
09-06-09, 03:17 PM
#42
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on my kaaz i just ran there oil with the there additive already in it. Broke it in properly but it chattered bad. Which was perfectly normal due to a 1.5 way 100 percent lock up on a FWD. But it handled soo GOOD..
09-07-09, 02:31 PM
#43
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Not sure if you guys know, but TOM's will be introducing an LSD for the IS F soon. Not sure if it will be a 2 or 3 way, but there is one in development.
09-07-09, 06:57 PM
#44
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Its available... Tom's Hyper Sport LSD - IS-F part# 41301-THD06
But as Lobuxracer has mentioned, these are "clutch type LSDs, so they're going to chatter"..
I should be easier to get our hands on the IS-F Torsen Units, which are grear driven..
IS-F Torsen LSD
Well there are currently 2 companies right now that have installed a True Mechanical LSD into a 2008-2009 IS-F differential.. ..
but in Japan..
One is the Tom's LSD unit (1 way type).. $2,040. USD
The other is an OS Giken LSD unit (1.5 way type).. $2,700 USD
There is hope...
Joe Z