3.266 diff crown and pinion - fit ISF diff or not?
#46
Driver School Candidate
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Join Date: Oct 2014
Location: AU
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Yeah look sorry for getting everyones hopes up but life has been pretty difficult for me these past 6 months, ive had to move house 3 times and dealt with a bunch of other relationship **** and stress that has just left anything car-related on the back burner.
I still want to go ahead and do this but i cant give a timeframe as to when, sorry.
I still want to go ahead and do this but i cant give a timeframe as to when, sorry.
#47
Instructor
iTrader: (6)
I figured it out, the info is posted here: https://www.clublexus.com/forums/is-...omparison.html post 5 & 6. I can not confirm at this point (getting a diff this weekend) if the ring and pinion is interchangeable with the f carrier but we will know soon. The crown set you have should fit in the sc housing if it is a 200mm (small diff) set otherwise you will need the big diff. All the diff info was sourced on http://www.supraforums.com/forum/sho.../topics/608545
supra-2urgse.com
supra-2urgse.com
#48
Instructor
iTrader: (6)
Man this was so disappointing, I went to scrap yard last weekend and the entire back end of the 99 sc400 was yarded out already.. I'm still looking around, might just buy another pumpkin n axles from another car to play with and if it works then I'll order the r&p n LSD for it.
#50
A lot of Ring N Pinions will fit into a FD21A carrier
49/15 = 3.266 = 41201-39717/41201-80763 bolts right up to O.S. GIKEN TY391-HC. I proved it this morning.
Lexus OEM open diff 41301-50030 & 41301-50031 = O.S. GIKEN TY391-HC
Available Ring N Pinions for TY391-HC:
47/11 = 4.273 = 41201-29118, 49/12 = 4.083 = 41201-59176, 47/12 = 3.917 = 41201-59156, 49/13 = 3.769 = 41201-59065,
47/13 = 3.615 = 41201-59055, 45/13 = 3.461 = 41201-49155, 47/14 = 3.357 = 41201-59215
Rear diff carrier w/cooling fins on bottom = 41111-30130 <--Found on the F sport models, Fs
Bolts:
90105-12219 spec = M12x1x20, head diameter is 24mm
90105-10417 spec = M10x1.25x26, head diameter is 20mm (I replaced w/ARP 763-1002)
Pics of my custom built FD21A below
FD21A top view
FD21A left view
FD21A early IS-F Al cover
Lexus OEM open diff 41301-50030 & 41301-50031 = O.S. GIKEN TY391-HC
Available Ring N Pinions for TY391-HC:
47/11 = 4.273 = 41201-29118, 49/12 = 4.083 = 41201-59176, 47/12 = 3.917 = 41201-59156, 49/13 = 3.769 = 41201-59065,
47/13 = 3.615 = 41201-59055, 45/13 = 3.461 = 41201-49155, 47/14 = 3.357 = 41201-59215
Rear diff carrier w/cooling fins on bottom = 41111-30130 <--Found on the F sport models, Fs
Bolts:
90105-12219 spec = M12x1x20, head diameter is 24mm
90105-10417 spec = M10x1.25x26, head diameter is 20mm (I replaced w/ARP 763-1002)
Pics of my custom built FD21A below
FD21A top view
FD21A left view
FD21A early IS-F Al cover
Last edited by GR4NR1C3RF; 07-10-18 at 06:05 PM. Reason: pics added
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#52
Driver
So...... 2018 thread bump. Has anyone actually done this yet?! The vital piece of information is knowing if the tranny won't **** itself if it is a more subtle change. IE - 3.13 or 3.26 final drive change.
EDIT - The 3.133 uses the AA80F transmission (Lexus ISF and LS460/Crown Majesta uses AA80E transmission) The AA81E has 2.937 in the GS350 & 3.133 in the IS350.
So perhaps there is an element of truth to the transmission being 'paired' to the final drive ratio. Maybe a 3.26 might be just within the 'range' of not confusing it? I honestly could not tell unless someone took the plunge and tested it lol.
EDIT - The 3.133 uses the AA80F transmission (Lexus ISF and LS460/Crown Majesta uses AA80E transmission) The AA81E has 2.937 in the GS350 & 3.133 in the IS350.
So perhaps there is an element of truth to the transmission being 'paired' to the final drive ratio. Maybe a 3.26 might be just within the 'range' of not confusing it? I honestly could not tell unless someone took the plunge and tested it lol.
Last edited by KPCresta; 03-12-18 at 05:33 AM.
#54
Intermediate
iTrader: (2)
Update?
Yeah look sorry for getting everyones hopes up but life has been pretty difficult for me these past 6 months, ive had to move house 3 times and dealt with a bunch of other relationship **** and stress that has just left anything car-related on the back burner.
I still want to go ahead and do this but i cant give a timeframe as to when, sorry.
I still want to go ahead and do this but i cant give a timeframe as to when, sorry.
Did everything workout? Did you get the chance to do anything with the Diff?
#56
Revive!
Seems like the general consensus is that the IS350 differential is too aggressive for the ISF. So, I have on order a GS350 rear differential carrier assembly. Through searching on this forum, someone did a direct swap with the IS350 diff on a GS350, so my thoughts are if that is a direct fit, GS350 to ISF in theory is a direct fit. GS350 diff is 3.679 vs the ISF 2.973. If anyone is interested and would like me to start a new thread outlying my thoughts on this once I get it installed, let me know. I'm set to receive the carrier on 5/9/2019 (according to fedex tracking). I should be able to get to the install Friday evening if not this Thursday, I only have one set of hands though , no one I know is a "car guy/gal" around me. I'll test responsiveness in manual and auto throughout the city and I'll go to some back roads to simulate highway speeds and of course, do some WOT. These are my initial thoughts using rpm/mph calculators on dragtimes.com and analyzing what I will be at in the city... I usually shift around 2400 rpm for city driving until I am at a cruising speed which is 45 in G8 at 1200rpm (usually downshifts me to G7 if I dip under 45) or 60 in G8 at 1600rpm. So at 2400rpm until that, my MPH from G1-G4 is 13.6, 22.95, 33.55, 42.7. If I stay with the same driving style, I will need G1-G5 10.99, 18.54, 27.11, 34.5, 41.03. 45 in G8 at ~1500rpm or 60 in G8 at ~2000rpm. As you can tell, I am bored, sorry for the ramble!
#57
Instructor
Seems like the general consensus is that the IS350 differential is too aggressive for the ISF. So, I have on order a GS350 rear differential carrier assembly. Through searching on this forum, someone did a direct swap with the IS350 diff on a GS350, so my thoughts are if that is a direct fit, GS350 to ISF in theory is a direct fit. GS350 diff is 3.679 vs the ISF 2.973. If anyone is interested and would like me to start a new thread outlying my thoughts on this once I get it installed, let me know. I'm set to receive the carrier on 5/9/2019 (according to fedex tracking). I should be able to get to the install Friday evening if not this Thursday, I only have one set of hands though , no one I know is a "car guy/gal" around me. I'll test responsiveness in manual and auto throughout the city and I'll go to some back roads to simulate highway speeds and of course, do some WOT. These are my initial thoughts using rpm/mph calculators on dragtimes.com and analyzing what I will be at in the city... I usually shift around 2400 rpm for city driving until I am at a cruising speed which is 45 in G8 at 1200rpm (usually downshifts me to G7 if I dip under 45) or 60 in G8 at 1600rpm. So at 2400rpm until that, my MPH from G1-G4 is 13.6, 22.95, 33.55, 42.7. If I stay with the same driving style, I will need G1-G5 10.99, 18.54, 27.11, 34.5, 41.03. 45 in G8 at ~1500rpm or 60 in G8 at ~2000rpm. As you can tell, I am bored, sorry for the ramble!
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Positron (11-09-20)
#58
#60
Moderator
If it works, I’ll order a set of gears and have them put in my 2013 diff. I’d love to change gears but fear the auto computer