3.266 diff crown and pinion - fit ISF diff or not?
05-10-19, 05:57 PM
#61
I’m not leaving y’all in the wind here, I’ve missed the diff package twice now 
. I just requested they come a little later on Monday. I can’t pick up from the shipping center because FedEx ground is closed on weekends
. I just requested they come a little later on Monday. I can’t pick up from the shipping center because FedEx ground is closed on weekends
05-10-19, 06:53 PM
#62
Instructor
05-10-19, 07:46 PM
#63
05-13-19, 08:19 AM
#64
Moderator
This could be a game changer. I want to run 11s, but am stuck in the low 12s. This diff gear should get me there.
05-13-19, 02:19 PM
#65
Tech Info Resource
iTrader: (2)
The spool in the GS diff from 2007 to 2011 is the same part number as the spool in the IS F, so, yes a Cusco or Giken spool would fit just fine.
EDIT - the ratio in the GS from 2007 to 2011 is the same as the IS F and the LS460/460L. If this is a later model GS, then there may not be a proper limited slip spool available.
EDIT - the ratio in the GS from 2007 to 2011 is the same as the IS F and the LS460/460L. If this is a later model GS, then there may not be a proper limited slip spool available.
05-13-19, 02:32 PM
#66
Tech Info Resource
iTrader: (2)
And the more I dig into this, I don't seen any GS with a ratio different from our 2.97:1 except the GS 200t, and it has a 3.96:1 set. That would be not a lot different from the old IS350 diff.
What model year GS350 is this unit out of?
What model year GS350 is this unit out of?
05-15-19, 05:32 PM
#67
05-15-19, 06:40 PM
#68
2013 gs350 f sport (rear of course). Everyone, So far looks like it’s going to fit by taking dimensions under the car. I do not have time until the weekend to start the job. Lobux, you had me second guessing myself so I opened it up and calculated the ratio. 49 teeth on the ring, 13 teeth on the pinion. 49/13 = 3.769.
05-15-19, 07:21 PM
#69
Tech Info Resource
iTrader: (2)
I see that, but that diff isn't made for the power the IS F makes. Hope it works out for you. There are no V-8s with that differential.
Wait - I take that back - the SC430 uses the same spool. Not sure about the housing though. Still a little concerned about this being stout enough.
Wait - I take that back - the SC430 uses the same spool. Not sure about the housing though. Still a little concerned about this being stout enough.
Last edited by lobuxracer; 05-15-19 at 07:35 PM.
05-15-19, 07:26 PM
#70
Moderator
05-15-19, 07:39 PM
#72
How did anyone know the is350 diff was built for the power of an isf without trying? How will anyone know if a gs350 diff is built for the power of an isf without trying? Was there some research someone did before the swap that told them a v6 is350 rear diff is built for a v8 isf??
05-15-19, 07:42 PM
#73
Tech Info Resource
iTrader: (2)
No, the pinion bearings are all different and that's just a quick check. The bearings and the housing are what make the diff stout or not. It's really hard to say what the outcome will be. Admittedly Lexus/Toyota build their diffs very stout, but for them to decide to do something really completely different for the IS F, RC F, and GS F says they have concerns about the longevity of the diffs in the 350s with the torque that comes out of the AA80E.
05-15-19, 07:47 PM
#74
I guess we will have to see, 2GR FSE was used in the is350 and gs350, similar output so I can’t see them making one diff “weaker” than the other. If the is350 diff was holding in a isf, I am sure the gs350 will too.
05-15-19, 07:53 PM
#75
Tech Info Resource
iTrader: (2)
Post some pics of the F-Sport unit if you can. There are only a few differences in the parts between the IS F diff and the IS350 diff. I have a feeling they relate to cooling more than anything.