Rear Differential Thread
11-01-07, 09:17 PM
#1
Rear Differential Thread
Ok, I just want to get some solid info about the rear differential. I know there's a bunch of you guys upgrading from the stock GS400/430 to the supra TT 3.76 rear end. Is it a straight bolt on? How about that rear end going on a GS300? I've read that driveshaft modification for the GS3 is necessary.
The reason I'm asking is because one of my buddies is gonna be parting out his GS400 in the near future. I'm thinking about buying his 3.76LSD rear. He doesn't have a stock differential laying around so I was wondering if the GS300's 3.92 rear would bolt onto a GS4.
It would be really helpful if someone can provide a detailed explanation of what needs to happen to make these differential fit.
The reason I'm asking is because one of my buddies is gonna be parting out his GS400 in the near future. I'm thinking about buying his 3.76LSD rear. He doesn't have a stock differential laying around so I was wondering if the GS300's 3.92 rear would bolt onto a GS4.
It would be really helpful if someone can provide a detailed explanation of what needs to happen to make these differential fit.
11-02-07, 09:38 AM
#4
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3.76 LSD is a direct bolt on for the GS400, and gives a bit more scoot than the stock 3.26 ratio. but for the GS300, you'll want at least the same 3.92 ratio. Not sure if there is a Supra LSD with that ratio. Might need to get the LSD unit to use with your existing ring/pinion/pumpkin. Major labor to go that route.
11-02-07, 10:57 AM
#5
3.76 LSD is a direct bolt on for the GS400, and gives a bit more scoot than the stock 3.26 ratio. but for the GS300, you'll want at least the same 3.92 ratio. Not sure if there is a Supra LSD with that ratio. Might need to get the LSD unit to use with your existing ring/pinion/pumpkin. Major labor to go that route.
So, he probably doesn't mine by going down in gearing (from 3.92 to 3.76;slower acceleration) because he will have tons of acceleration already with his future "enhancements" 
. I think he's just looking at this unit for it's LSD characteristics.
11-02-07, 10:57 AM
#6
Well, I want to drop my GS300 down to a 3.76 ratio and gain LSD at the same time. I have turbo and a high stall torque converterso power is not an issue. Longer gearing is actually better with the turbo since I spend more time in boost instead of shifting.
I know the Supra TT 3.76 rear end bolts up directly to the GS400/430. But I was wondering if the 3.92 rear of the GS300 would bolt right up to the GS400/430. I heard some driveshaft modifications were necessary.
Basically here's exactly what I need done.
Pull off 3.76lsd rear off GS400.
Pull off stock 3.92 off my GS300.
Put 3.76 LSD on my car.
Put 3.92 rear on GS400.
I hope I won't have to go all custom on the driveshafts and all.
I know the Supra TT 3.76 rear end bolts up directly to the GS400/430. But I was wondering if the 3.92 rear of the GS300 would bolt right up to the GS400/430. I heard some driveshaft modifications were necessary.
Basically here's exactly what I need done.
Pull off 3.76lsd rear off GS400.
Pull off stock 3.92 off my GS300.
Put 3.76 LSD on my car.
Put 3.92 rear on GS400.
I hope I won't have to go all custom on the driveshafts and all.
11-13-07, 06:27 PM
#7
Ran into a few problems lol. Seems as if the driveshaft for the GS400 is slightly different than the GS300. The flange at the very end of the driveshaft that mates to the rear diff isn't the same size. The GS300 one is slightly smaller...only by like a few millimeters, but that's enough to prevent it from bolting up.
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