The Definitive Differential Thread

[Cj7379]

Thanks for the INFO !!!

[kbc749]

I just wanted to say thank you.

Every single time I have a question about the new upgrade I'm wanting to do. I can come here and find a sticky or a wealth of information very easily. Thank you to the starter of this thread and also this awesome community in general!

[PJMilton]

I totally agree! I am going to tackle install of OSG tomorrow on my 2017 Nismo and feel much more confident about the job after reading all the insights from the guys here on the forum. Have a great weekend and THANKS AGAIN!

Originally Posted by kbc749

I just wanted to say thank you.

Every single time I have a question about the new upgrade I'm wanting to do. I can come here and find a sticky or a wealth of information very easily. Thank you to the starter of this thread and also this awesome community in general!

[Rusty]

Originally Posted by Hotrodz

No, they are noise on slow speed tight turns like in parking lot or turning from a stop at a stop light. It's like having a truck in 4 wheel drive and trying to make a tight turn on pavement.

Sent from my SM-N910P using Tapatalk

With the OS Giken gear lube. My OS Giken diff quite. You don't even know it's there until you start to hammer on the loud pedal.

[Spooler]

Originally Posted by Rusty

With the OS Giken gear lube. My OS Giken diff quite. You don't even know it's there until you start to hammer on the loud pedal.

I can vouch for that. Dang if it ain't quite as a mouse!!!!!!

[eliboy]

Hey guys,
My Cusco 1.5 way is being build as we speak.
I have 2014 Nismo 370z and needed to order new stub for the diff. I talked with Z1 that told me that the 2014 Nismo have traded stub hols and you can’t find this part even from Nissan. They sent me a 2013 stub with hardware. From my understanding the hols size on the stub is different. I don’t have my car at the shop I just took the diff there, do you know about this issues with Nismo 2014? When I will try to put back the diff I will have an issue with the hols sizes. Any ideas? Do I need to take the other side off the car also and take it to the shop? Pleas help me as this diff change is very bumpy for me (the car is on jack stands over 3 weeks now)

[Auzzie370]

Hello all,

Sorry to bring this back from the dead, as it has been necromanced already.

I have ordered the Cusco LSD251 L15 1.5 Way from Cusco directly and am expecting delivery in November.

I have a sport package with the OEM VLSD, was planning to order the short stub axle and the finned nismo cover. For cars with the OEM VLSD, are all the items on page 1 still applicable?

I intend to do spirited driving fortnightly, and a few track days a year. Is the finned cover necessary?

Thanks in advance.

[Rjk370z]

Some good info on this thread. Ty all!

[Spooler]

I want to add one thing. If you order an OS Giken diff you can have it tuned to your liking before it is shipped to you. It is only $150.00 extra to have it done.

[Tedmeister]

My car is just used for road racing. Just curious if anyone has feedback
on having Z1 do the swap. I have a manual factory VSLD. From the
comments I'm leaning toward the OSG or the Nismo GT Pro. When people
talk about maintenance, what does that mean? If it means removing the
diff, opening it up and replacing clutch plates, after how many miles or
track hours, will this have to be done.
This seems like a very time consuming swap. My concern is that a shop
will call it "close enough" rather than spend another two hours taking it
apart, adjusting it and re-assembling it. My hope is that Z1 has done a lot
of swaps and the person doing has the patience to it right.
Do guys, have a gear recommendation for a road racing car?

[Spooler]

Originally Posted by Tedmeister

My car is just used for road racing. Just curious if anyone has feedback
on having Z1 do the swap. I have a manual factory VSLD. From the
comments I'm leaning toward the OSG or the Nismo GT Pro. When people
talk about maintenance, what does that mean? If it means removing the
diff, opening it up and replacing clutch plates, after how many miles or
track hours, will this have to be done.
This seems like a very time consuming swap. My concern is that a shop
will call it "close enough" rather than spend another two hours taking it
apart, adjusting it and re-assembling it. My hope is that Z1 has done a lot
of swaps and the person doing has the patience to it right.
Do guys, have a gear recommendation for a road racing car?

Z1 did my car back in 2017 or so. The clutch type diff will require more frequent fluid changes. That's it. You will also benefit greatly by installing a diff cooler. The diff cooler will keep the fluid from being cooked which will require less fluid changes. If you buy the OS Giken, use the OS Giken diff fluid. It eleminates the driveability issues like the clunking and banging on tight turns.

[filip00]

I would recommend going with OS Giken. I track the car, take it for drift events and the LSD works incredibly well.

The maintenance boils down to changing the fluid every year or two, depending on mileage and usage. OS Giken plates aren't meant to be maintained.

Gearing is a better topic...depending on if you plan on boosting the car or keeping it stock, you might want to go with a shorter final drive.

[Spooler]

Originally Posted by filip00

I would recommend going with OS Giken. I track the car, take it for drift events and the LSD works incredibly well.

The maintenance boils down to changing the fluid every year or two, depending on mileage and usage. OS Giken plates aren't meant to be maintained.

Gearing is a better topic...depending on if you plan on boosting the car or keeping it stock, you might want to go with a shorter final drive.

For a NA track car to most people run 18in wheels on that would not be wise. For a boosted car with 18's, they go to 3.33's.

[filip00]

Originally Posted by Spooler

For a NA track car to most people run 18in wheels on that would not be wise. For a boosted car with 18's, they go to 3.33's.

Agreed. There are other variations though...I have a street/track car, with 19s, so shorter gearing is very nice. Boosted definitely requires longer gearing, especially on 18s, as you said...

[xavier]

Hi,

If I understand correctly.
With a 7AT VLSD 370z car.
If I want to install a 350Z MT VLSD (or 370Z MT with VLSD) pumpkin on a 370Z 7AT car (or 370Z MT car) , with Quaife (QDF13L).
I'll need two short flanges.
2 solutions...
1) (driver) flange 38220-1NC1B and (passenger) flange 38220-1NC1A, and it need to cut the 38220-1NC1A flange. The 38220-1NC1A flange loses a spline length.
2) Buy two 38220-1NC1B flanges (because it's short) to use on the passenger and driver sides (without to cut). This way, I have a longer spline length on the passenger side... identical to the driver's side longer spline length and with a gasket too.

Correct?
Image2.jpg

in the solution number 2, with two 38220-1NC1B flanges , passenger and driver sides:
more longer spline length = more power transmission, or, more strong.
i will use two 38220-1NC1B flange, not flange 38220-1NC1A with cut, does 38220-1NC1B flange will have same comportment than flange 38220-1NC1A cut ?

for information, the pumpkin of the 350z MT (3.538) is identical (external) fixing points on the 370z 7AT, identical height for the drive shaft and the transmission universal joints as on the 7AT (3.357) 370z, no misalignment (on 2 European cars, 350z MT and 370z 7AT) with the axes, checked at 0.5mm on the fixing points on the chassis, and on the rotating axes.

pictures (38220-1NC1B and flange 38220-1NC1A) come from Z1motorsports
https://www.z1motorsports.com/rear-d...ft-p-4622.html

38220JK01ADetailsHalf.jpg
38220JK01BDetailsHalf.jpg

38220-1NC1B = 38220-JK01B
38220-1NC1A = 38220-JK01A

Many thanks