FRT and RR Differential upgrade potential - info

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neitjnf

Member
So I'd like to upgrade both my diffs to limited slip and have been doing some research. Here's what I found.

FX50 V8 Front Diff without ring+pinion Part Number: 38421AR000
Most AWD infinitis and even the R35 GT-R use the same part number in the front diff, except for the ring+pinion diff ratios.
Easy to find albeit expensive upgrade, R35 GT-R front aftermarket LSD and done.

FX50 V8 Rear Diff without ring+pinion Part Number: 384211CA0A - unique to the V8 VK50VE ??

FX35/7 V6 Rear Diff without ring+pinion Part Number: 384210C00A (2WD) or 384210C50A (AWD)
shared with G35/G37, 350/370Z, Frontier 2.5 and 4.0, Pathfinder, Xterra and others

So, what to do with the rear diff of my FX50? Will the V6 unit fit? If this is the case then an aftermarket 350Z or 370Z LSD will work.
If the V6 unit won't fit then the entire pumpkin may fit or is the rear subframe unique as well? Anyone knows?
 
I doubt anybody has done this sort of modification to the FX50.

My first question is obviously why do you need LSD on your AWD FX50? Are you planning more rock climbing with an SUV designed to be on the pavement? lol
 
during spirited driving (or yes even offroad :tongue:), the reactive brake traction control is not up to par. I hate to spin one tire and wait until traction control brake engages and reduces power, transfers torque up front and then pulls ahead... So LSD's front and rear will provide a lot better performance and driving experience.

and yes, I plan to take it to the drag strip, open track days and more mild off roading. It behaves good as is on flat shallow mud and sand and fairly smooth rocky trails but as soon as it starts spinning one tire it wont go anymore and if pushed the transfer case overheats.

---------- Post added at 02:07 PM ---------- Previous post was at 09:42 AM ----------

I did find more info, confirmed the front is an F160A unit same as R35 GT-R and the rear is an R230 unit (R200 in the V6) shared in several Nissans. There are good upgrade options available even an ARB Air locker R230 unit :) now to save some $$ to get this going :D
 
I had never driven a car with an LSD until I got the Z. It's probably my favorite part about it. I don't know how to describe it, but it makes you feel like a pro drifter because it does such a good job keeping traction when the rear kicks out.
 
neitjnf said:
Quaife offers helical torsen type LSD's for the front (R35) and rear (300ZX TT for the V8). May go this route.
Click to expand...

I've been looking at the Quaife LSDs. They are pricey, but you do get what you pay for. There are a number of DIYs on the Z/G forums, and they look pretty straight forward. In one of the DIY, the guy had to put in 2 OEM bearing and then put everything back together. The rear LSD is $1250, while the front is $1300.

I think the front LSD is a nice to have thing. There isn't enough power that get sent to the front to warrant a full performance LSD.
 
when doing donuts in mud and only one front and one rear tire spin.... I want to do both. The brake traction control helps somewhat but I'm used to the torsen in my RX-7 and love the way it never loses traction on only one tire, if it's going to spin, both spin.
 
The FX is surprisingly capable offroad, having not great ground clearance and articulation but with LSDs front and rear would make it awesome as far as traction goes.
 
I did more research on the Quaife LSD and I found some interesting information:
2nd Gen FX35/37 part numbers are 384210C00A (2WD) or 384210C50A (AWD) like neitjnf mentioned in OP. However, the 384210C00A (2WD) is also in auto transmissions 370Z and G37 (open diff). The 384210C50A (AWD) is also in manual transmissions 370Z and G37 (open diff). The only difference between the two diff cases is the thickness of the bearing/crown wheel, where the ring gear sits on.

Becareful while ordering LSD. I ordered the wrong part and now I need to do an exchange... :tdown:
 
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So, G35/37 differentials seem to fit many models, I surmise my FX 37 almost certainly does not have LSD, it acts all electronically upset if it starts to break loose.

What's the part # for the LSD with 10% higher numerical ratio? Steeper gears, quicker take off. You know? :cool:
 
Kanedean said:
I did more research on the Quaife LSD and I found some interesting information:
2nd Gen FX35/37 part numbers are 384210C00A (2WD) or 384210C50A (AWD) like neitjnf mentioned in OP. However, the 384210C00A (2WD) is also in auto transmissions 370Z and G37 (open diff). The 384210C50A (AWD) is also in manual transmissions 370Z and G37 (open diff). The only difference between the two diff cases is the thickness of the bearing/crown wheel, where the ring gear sits on.

Becareful while ordering LSD. I ordered the wrong part and now I need to do an exchange... :tdown:
Click to expand...
So, which number is RWD lsd, and higher numerical ratio than my stock? Like 369:1?
 
I have a 3.692 lsd from a 2013 G37, the flanges on the output shafts are 10/15% smaller than FX's, I ordered some new FX 50 (S?) ones, but only one came in today, I'll know more about interchange ability manana.
 
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Fuggetaboutit!

I'm going to just enjoy the VDSC for a while. Too many things can go wrong if I start monkeying with this combo. They're not making it easy.

Nismo didn't even have lsd for second gen. They have it, just not for an FX, G's are covered. But for us They're vested in the VDSC.

Wave track or Quaife?
 
Kanedean said:
I did more research on the Quaife LSD and I found some interesting information:
2nd Gen FX35/37 part numbers are 384210C00A (2WD) or 384210C50A (AWD) like neitjnf mentioned in OP. However, the 384210C00A (2WD) is also in auto transmissions 370Z and G37 (open diff). The 384210C50A (AWD) is also in manual transmissions 370Z and G37 (open diff). The only difference between the two diff cases is the thickness of the bearing/crown wheel, where the ring gear sits on.

Becareful while ordering LSD. I ordered the wrong part and now I need to do an exchange... :tdown:
Click to expand...

Did you get yours sorted out?
 
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