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Discussion Starter #1
I want to get a LSD to replace my open diff for my R154 is300. I know close to nothing about them and just started a very small bit of research about them like how different LSDs have different gear ratios. I'm looking to buy a is300 LSD or looking for info on which LSD to go with... Maybe where I can purchase said LSD as well... I want to keep similar if not the same gear ratios, I love the way my car drives and not really looking to get into different gear ratios... I just want to be able to hit some donuts and do a little drifting. I've looked for IS300 LSD on ebay and see different options like Manual / Automatic LSD, I've also read people say that IS300 LSD and open diff look exactly the same so you could purchase one off ebay and be getting ripped off??? Someone please help guide me in the right direction with any recommendations on which LSD to get, I'd appreciate it!
 

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The IS300 came with either a 3.73 manual diff or a 3.9 auto diff. As long as no one has swapped your diff, it’s ratio can be determined by what trans your car originally came with. When buying a replacement you can look at the diff to see if it has a sticker (will say m96, m98, m85, or m82)... but it may have fell off by now though. M85- manual lsd and m96- auto lsd and the other two would be open diffs. Junkyards will be the best bet for getting an LSD. Look for a car with the B01C or B01B code on the drivers door jamb build tag - these are LSD. B01A would be an open diff. You can eBay an lsd but it will be expensive because bIdDinG wAr, and shipping will be high too. hollanderparts.com, car-parts.com and similar will have an lsd that should be cheaper and can ship (but it is heavy so that won’t be cheap). Sometimes you can even find an lsd diff that is listed as open diff super cheap. If you find a local diff that you’re unsure of, you can look thru the axle holes in the diff or pop the back cover off. You can see the Torsen unit clearly either way.
 

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Discussion Starter #3 (Edited)
Thank you! I guess my next stupid question just to be specific, is the M85 the only OEM option between M96 and M85 LSD for a manual transmission is300, a M96 wouldn't work with a manual transmission correct? Or the M96 would work and people only mention Auto because the automatic M96 has slightly different gear ratios from the manual M85? Assuming the M85 is the only option between the two, do you know of or recommend any aftermarket manual LSDs? I was looking around and found OS SuperLock LSD for Toyota SXE10 Altezza but haven't really looked any further.
 

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I guess my next stupid question just to be specific, is the M85 the only OEM option between M96 and M85 LSD for a manual transmission is300, a M96 wouldn't work with a manual transmission correct? Or the M96 would work and people only mention Auto because the automatic M96 has slightly different gear ratios from the manual M85? Assuming the M85 is the only option between the two, do you know of or recommend any aftermarket manual LSDs? I was looking around and found OS SuperLock LSD for Toyota SXE10 Altezza but haven't really looked any further.
They work. It will be a 200 rpm difference. Higher number gets more rpm and quicker from a stand still.
 

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If you have a manual, the 3.93 auto LSD is a little better than than the 3.72 manual LSD. Toss a Supra flywheel and clutch up front, and go have some fun.
 

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Discussion Starter #7
I'm reading another post on the Forums saying M96 is Open diff and M98 is LSD??
 

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From what I found, the m85 is a manual LSD - 3.73 gears. m86 - is manual open diff - 3.73. The m96 - auto open diff - 3.93. The m98 - auto LSD - 3.93.
Hope i got that right.
 

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On the same topic here. A buddy of mine gave me the lsd from his brz. Does anyone know if I’ll Be able to drop it into my IS pumpkin? It’s an auto open M96
 

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On the same topic here. A buddy of mine gave me the lsd from his brz. Does anyone know if I’ll Be able to drop it into my IS pumpkin? It’s an auto open M96
You said its an LSD, and then said its an auto open M96. Think he gave you an open diff, so you dont have an LSD.
 

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I currently have the auto m96 open diff. he gave me the stock lsd from his brz without the casing.
There are treads on that diff. It bolts in other than drilling the pinion support bushings or replacing them. The whole diff goes in. Try doing a search next time.
 

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There are treads on that diff. It bolts in other than drilling the pinion support bushings or replacing them. The whole diff goes in. Try doing a search next time.
I don’t think you understand what I am saying. Although I appreciate the research advice I have not been able to find any research on using an IS300 pumpkin (that’s the housing) with whats inside a brz housing. the actual LSD. So in other words. Take the m-96 apart remove the open diff and put the brz lsd in the m-96 housing. Thanks
 

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Why would you take it apart? They are the same housing. If you read the documentation. You would know this.
 
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