IS300 Torsen LSD into IS250
08-11-11, 09:47 PM
#1
IS300 Torsen LSD into IS250
So I've been thinking about doing this for some time now, I had researched it before I bought my IS, and it all seems pretty straight forward; I don't know if anyone has done this swap before, but it shouldn't be too bad.
After calling around and looking for the last while, I finally managed to find a decent price on a 3.91:1 Torsen T-2 out of an Automatic IS300, so I ordered it yesterday and they dropped it off today. As Torsen's act like open diffs in almost all circumstances when testing them out of the car, I needed to open up the case to double check that it was in fact an LSD. I also wanted to check the gear pattern for wear and I wanted to make sure the diff looks "fresh" again on the outside of the case (throwing a used pumpkin into a brand new car and all that). I'm going to replace the 2 axle seals, pinion seal, drain and fill plugs, as well as the breather and then throw it into my IS250 next week sometime, provided all the parts I order come in soon. I want to replace the cover bolts and there aren't any around at the moment.
Basically the IS300 uses the same differential case/setup as the IS250 RWD and 09+ IS250 AWD. The 06-08 IS250 AWD uses a smaller diff and the IS350 uses a larger diff (same size as the IS F). I'll need to pull the axle stubs out of the diff as well, since the 2IS doesn't use them (the axles go right into the diff, and are splined, instead of bolt-on).
I am quite looking forward to how it feels going from the 3.73:1 Semi-LSD to the 3.91:1 Torsen. Should be a tad more peppy, I'd think, especially off the line.
More pics/info as I go along.
Jeff
After calling around and looking for the last while, I finally managed to find a decent price on a 3.91:1 Torsen T-2 out of an Automatic IS300, so I ordered it yesterday and they dropped it off today. As Torsen's act like open diffs in almost all circumstances when testing them out of the car, I needed to open up the case to double check that it was in fact an LSD. I also wanted to check the gear pattern for wear and I wanted to make sure the diff looks "fresh" again on the outside of the case (throwing a used pumpkin into a brand new car and all that). I'm going to replace the 2 axle seals, pinion seal, drain and fill plugs, as well as the breather and then throw it into my IS250 next week sometime, provided all the parts I order come in soon. I want to replace the cover bolts and there aren't any around at the moment.
Basically the IS300 uses the same differential case/setup as the IS250 RWD and 09+ IS250 AWD. The 06-08 IS250 AWD uses a smaller diff and the IS350 uses a larger diff (same size as the IS F). I'll need to pull the axle stubs out of the diff as well, since the 2IS doesn't use them (the axles go right into the diff, and are splined, instead of bolt-on).
I am quite looking forward to how it feels going from the 3.73:1 Semi-LSD to the 3.91:1 Torsen. Should be a tad more peppy, I'd think, especially off the line.
More pics/info as I go along.
Jeff
Last edited by Jeff Lange; 08-11-11 at 10:35 PM.
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08-12-11, 12:51 AM
#8
01-05 IS300 models have a 205mm rear differential
06-08 IS250 AWD models have a 190mm rear differential (A Torsen from an IS200/RS200 Altezza might work well in this application)
06-11 IS250 RWD & 09-11 IS250 AWD models have a 205mm rear differential (The IS300 Torsen should be a bolt-in upgrade for this application)
06-11 IS350 and IS F models have a 208mm rear differential
So no, this won't work for an IS350, you may be able to use a 2010-11 IS F Torsen LSD, but you wouldn't want to use the complete IS F pumpkin, as the IS F has a 2.9'ish final drive, which wouldn't be a good match to the IS350's transmission gearing. (IS350 has a 4.08:1 final drive). I don't know if anyone has tried to put the IS F Torsen into an IS350 differential though, so I don't know much about that.
Jeff
06-08 IS250 AWD models have a 190mm rear differential (A Torsen from an IS200/RS200 Altezza might work well in this application)
06-11 IS250 RWD & 09-11 IS250 AWD models have a 205mm rear differential (The IS300 Torsen should be a bolt-in upgrade for this application)
06-11 IS350 and IS F models have a 208mm rear differential
So no, this won't work for an IS350, you may be able to use a 2010-11 IS F Torsen LSD, but you wouldn't want to use the complete IS F pumpkin, as the IS F has a 2.9'ish final drive, which wouldn't be a good match to the IS350's transmission gearing. (IS350 has a 4.08:1 final drive). I don't know if anyone has tried to put the IS F Torsen into an IS350 differential though, so I don't know much about that.
Jeff
08-12-11, 01:19 AM
#10
http://www.dezod.com/pd-os-giken-limited.cfm
I will be getting 250 versions of it as well for my 250.
http://www.dezod.com/pd-os-giken.cfm
Last edited by Sango; 08-12-11 at 01:24 AM.
. I would be interested
08-12-11, 10:24 AM
#14
Personal perference, I prefer the mechanical/helical gears of a Quaife LSD :
http://www.autotech.com/product/oem-...arts-clearance
No clutch disks to worry about. Here's the one I installed into my Civic trans :
Jeff, have you or others done the measurements to see if a 350 final drive ring gear would at all fit on a 250 diff/300 Torsen LSD?
http://www.autotech.com/product/oem-...arts-clearance
No clutch disks to worry about. Here's the one I installed into my Civic trans :
Jeff, have you or others done the measurements to see if a 350 final drive ring gear would at all fit on a 250 diff/300 Torsen LSD?
08-12-11, 10:49 AM
#15
So let me get this straight, the older is300 has a real lsd and the is250 only has a semi LSD? Do you know what exactly is a semi-LSD and how is different from a torsion LSD? Its one of those mysteries on the Lexus brochure that no one really talks about. The Semi LSD and the 2-piston brake calipers on the IS250 (I only see one piston).