IAGS400

I'm assuming this is the differential everyone is picking up when they switch to 3.76 is:

92-96 MKIV Supra
w/turbo, MT (3.133 ratio) Limited Slip

97-98 MKIV Supra
w/turbo, AT (3.769 ratio) Limited Slip

So is it safe to assume this will fit in our car as well:

92-96 MKIV Supra
w/turbo, MT (3.133 ratio) Limited Slip

97-98 MKIV Supra
w/turbo, MT (3.133 ratio) Limited Slip

I know changing from 3.26 to 3.113 isn't the direction most people want to take. But my though is this might be a cheaper differential to purchase. I'd almost be willing to bet most people wouldn't notice the difference in performance and you'd be gaining the LSD to boot.

DumpedGS

iTrader: (1)

everyone gets the auto diff because it fits in the gs400 housing. from my limited research on the supra diff, the MT diff is larger and wont fit in the gs400 housing.


found a lead on a guy that has a couple parts SC300/400's in my area (what are the odds lol) sounds like he has an auto diff and a manual diff....going to do some searching and see if there is a difference between the 2.

IAGS400

That would be great to see the differences.

GSJake

iTrader: (21)

12 -bolt 6-speed diff carriers wouldn't fit in the GS differential housing.
Different diameters to the 10-bolters on the GS.

3UZFTE

Alright, sorry to bust your ***** but you have all the information in front of you, as you posted it down farther in the thread. I wish I could tell you what I said was correct, because I bought a GS3 rear end from Viking Auto Salvage in Minnesota for like $97. At the time, I was planning on going LSD with the 3.92, but instead I just pulled it and ripped it apart and never bought the LSD. The 'A-series' diffs are GS/SC/Supra diffs which will all bolt up, with the exception of the 'B-series' differentials, which is the 6-speed Twin turbo. You can tell because it has 12 bolts for the ring gear, whereas all others have 10 bolts. Sorry I was quick to speak, as I missed that you were in Idaho. Goto www.car-part.com, I searched for a 98 SC, and it brought up quite a few, none under $100, but the closest I found to you I think is in Topperish, WA, but it says call. I do have a full GS300 (3.92) rear that has been sitting in my garage for about a year now. I have too many projects and things to work on to be able to shell out the $500+ it seems like it will take to put in an LSD insert, even from the Supra owners.

I ran with the stock 17's, with the 3.92 for a little while, the acceleration is noticeable, but being that I hate spinning one wheel, which I did with the 3.26 rear, so you believe I did it with the 3.92. I yanked it in favor of the stock GS4 rear, in hopes to find a used LSD insert for the cheap. There are a few members that have done this, but with the added power the of the V8, it likes to roast one tire. I am more of a cruiser anyways, so the only way I would give up the lower gears is in favor of an LSD gear set.

As he said, it has been discussed that it is best to have some real power, not just a stocker. The cheapest way to get LSD is buck up and buy a used diff from a MKIV Supra. He brings up a good point, with the size of your tires, it might dictate what exactly you want to do. For instance, if you use the stock 3.26 with heavy 20"s, it will give a completely different feel or response than lets says stock 17"s, with the 4.27 gearing. I am not one to tell anyone what to do, by all means if your hell bent on what your going after, do it. With that being said, I would stay away from welding the diff is you will literally be chirping your wheels on almost all of your turns. Again, do it, and then develop what works best for you. If you not drag racing or drifting, I wouldn't weld it up.

Let us know what you end up doing. I still have the GS3 rear end, and could end up getting rid of it if the price is right. It has about 160k on the clock, but that's nothing. I'd put it back together for you so you can just bolt it in.
Let me know if your interested and I'll check needs to be done to put it in your hands.

3UZFTE

Here is all the information you need (http://mkiv.supras.org.nz/specs.htm) to find out what will fit in your car in terms of the MKIV Supra. Your rear end is identical to a MKIV Supra 4-speed auto which came with the optional LSD, but very rare. It is referred to as the axle code and our housing is a 'A-type' housing, the Manual 6SPD LSD is a 'B-type', which signifies the 10 bolt ring gear vs. the 12 bolt ring gear. Towards the bottom of the page you will see a breakdown of the differentials. Not all ratios and options went from 93 to 98, so when I say that I am just saying that it is somewhere in those years. You can't use a 6-speed MKIV TT LSD (12 bolt) 'B-type' because it doesn't fit inside the 'A-type' housing. If you choose to buy the pumpkin, I believe you need to buy the housing, and axle shafts as the differential is a different shape as well. Why would you further gear the GS down from 3.26-3.13, you might not even need LSD as that point. You also can't use a MKIII/IS300 LSD because it is a differential style, and size. Here is what will work if it is pulled from a MKIV Supra/Aristo, not to say one couldn't be pulled from a JDM Crown, idk... I know that no Lexus came with an LSD.

93-98 MKIV Supra (JZA80)
w/turbo, 4-speed AT (3.76 ratio) LSD

93-98 MKIV Supra (JZA80)
w/o turbo, 5-speed MT (4.08 ratio) LSD

93-98 MKIV Supra (JZA80)
w/o turbo, 5-speed MT (4.27 ratio) LSD

93-98 MKIV Supra (JZA80)
w/o turbo, 4-speed AT (3.76 ratio) LSD

93-96 Toyota Aristo (JZS147)
w/ turbo, 4-speed AT (3.76 ratio) LSD

If you want to keep the 3.26 gearing, and just buy an LSD insert, look to spend a good $800-$1500 depending on the brand, most people get the TRD insert, but the cheapest I've found was $850, and it didn't include shipping. Since we have to order it at my dealer, they won't give me a price break, so I laughed at the parts guys when they told me $1000.... Anyways, looks for a used one or new one, either way it'll be a few pretty pennies.

As far as the articles or where to get your knowledge....
Good read, good info, not reeeeeeeally what your looking for, but it's the theory that counts.
https://www.clublexus.com/forums/per...0-pumpkin.html
He has a list of 4 threads, as well as some other useful information in there
http://www.supraforums.com/forum/sho...d.php?t=567267
And this is the main article where I got most of my info from, then it expanded from there...
http://www.supraforums.com/forum/sho...d.php?t=484348

Let know if your need any more help...

DumpedGS

iTrader: (1)

thank you guys for posting all this info...it makes it that much easier for the next guy that is searching for the same answers

and yes i will be dragging and drifting this beast. i am infatuated with building 4dr family type cars that go fast, corner hard, and are just a kick in the *** to drive/play with. i adore the creature comforts inside this car, and the capable power plant. this is just a small step in the overall scheme of things. drivetrain and suspension are first...then more power (already started collecting turbo parts) there is a method to my madness haha....ive driven a couple rwd's with welded diff's and its not as bad as everyone makes it out to be...the 240sx i drove only chirped the tires at like sub 5mph speeds. something i can live with in order to leave 2 solid black stripes at will

again, much appreciated!!

(PS...i posted up a shot in the dark thread on my local forum, and got a PM this morning from a guy that has a gs300 pumpkin from a car he parted out that had 80k on it....going to grab it this weekend for $80!)

3UZFTE

Good to hear, keep us updated as this community like photos and good deals. You can't beast an $80 diff can ya? Sorry I was quick to jump, I just remember doing tons of homework on this very topic. Not that there isn't a GS drifting, but I always have a sweet spot for 4 thousand lb. sedan sliding around corners with enough power to peel those tires off. Good luck with the build, and I hope I helped more than not.

DumpedGS

iTrader: (1)

u did, thanks

ROPADOPA

for reference, i have successfully swapped a few A series diffs. I have a six speed trans so i was looking to match my gear close to a supra without having to pay supra dollars.

My car a 99 GS300 . stock 390 gear...... i got a diff from a GS4xx that had a 3.27 gear in it. I be-leave the housings were the same but the companion flanges were the only differences between the gs3/gs4 . I then found a used LSD unit from a supra just the Differential , assembled all into my housing 3.27 ring and pinion and supra auto tt LSD unit. works excellent.

Hope this helps

3UZFTE

Ah, you are 100% correct, I forgot to tell DumpedGS the difference between the two housings in scratching the old brain with your questions. The companion flange, where the driveshaft bolts up to the diff is smaller on the GS3 than it is on the GS4. You need to swap over flanges, and then it will bolt right up. Since your taking out your stock GS4, you just swap the flanges over as the GS3 is going in. You can read more here, pretty easy and straight forward, only part to mind is the torque and pre-load on the pinion. Like I mention in the thread, I just my snap-on air gun, and didn't pay too much attention to the specs and it works fine... but I don't encourage you to do so. https://www.clublexus.com/forums/per...s300-diff.html

DumpedGS

iTrader: (1)

sweet! thanks again

sam430

iTrader: (10)

I recently got an LSD put in with stock gear on 2gs430. Since you had it for a while, how do you like it?

Do you have more power to take advantage of that gearing?

For those that owns the supra or have LSD w/power ... is 133% the max it really can handle? So does that mean the supra guys with more power are not running thier LSD and opt for another solution?

3UZFTE

Read his signature, it says he's GTE'd with a V160, so that would be a Yes.

I can't for sure say the power limit, but I am sure there is one. I know that the guys who are really making a lot of power are opting for the TRD LSD or carbonetics, tomei, kaaz, etc. However, for us GS owners, nothing we have would put down the same stock power as the GTE, I mean, close, but not the same. I know that there are a few people out there running 400+hp on them, however that is about 133% of 320hp, so....again most bust them up and go for the TRD, which seems to be significantly stronger. Just from what I've read, seen, and experienced.

sam430

iTrader: (10)

Ahh, I should be future proof then I wonder what JeffTsai is running. I might go above 400hp and still be ok... also, it's good info -- I don't have to baby the car as much knowing that (assuming no one ever got into problems with it except for Sakataj).