The Definitive Differential Thread

[osbornsm]

Parts Required for a Diff Upgrade

• 1x - Limited-Slip Differential (choose type from details below)
• 2x - 1L Diff Oil - (Motul 75/90)
• 2x - 38440-0C000 - Differential Side Bearing
• 2x - 38342-P9010 - Differential Side Oil Seal
• 2x - 11026-4N200 - Differential Drain Plug Crush Washer
• 1x - 38120-0C000 - Carrier Bearing Assembly
• 1x - 38140-0C00A - Pinion Bearing
• 1x - 38189-P0117 - Drive Oil Seal

Differential Types

• Viscous Type
  • OEM
• Torsen Type (Gear Driven)
  • Quaife $1,100
    • Different part # necessary if Factory VLSD is installed
    • Lifetime Warranty?
    • no harsh engagement
    • no special oil
    • no break in period
• Clutch Type
  • Cusco Type RS - $1,440
  • Kaaz Super Q - $1,250 <-- 1.5 or 2 way
  • OS Giken - $1,600 <-- Low maint / Smooth, Customizable by Manufacturer
  • Nismo GT Pro - $2,800 *cough

Differential Adjustability (Clutch-Type LSD are adjustable)

• 60% lock: DD and track fun on street tires.
• 80% lock: Street and track on wide high grip street tires or R comps.
• 100% lock: Drifting or a track only car on slicks.

Related Parts (to change while the diff is open)

• Whiteline Diff Bushings - $110 <-- Better / quieter for DD
• SPL Solid Bushings $160
• Finned Diff Cover $140
• Upgraded Diff fluid
• 4.08 Gears - $550
• Z1 Motorsports Differential Upgrade Kit $275
  • Whiteline Front/Rear Diff Bushings - $100
  • Finned Diff Cover - $140
  • 2 Liters Diff Fluid
  • 1 Tube Silicone

Related Info

• DIY: Rear Differential Oil Change
• Track Day Best practices