AMSOIL Shock Therapy Suspension Fluid #5 Light (STL)

AMSOIL Shock Therapy Suspension Fluid #5 Light (STL) Formulated for fade-free dampening and smooth rebounds in high-performance applications.

AMSOIL Shock Therapy Suspension Fluids are formulated with shear stable synthetic base stocks with high viscosity indices. The complete additive package reduces foaming, aeration and wear, while seal conditioners are added to keep seals soft and pliable. AMSOIL Shock Therapy Suspension Fluids have been tested and proven to be superior, balanced products recommended for a wide range of temperatures and applications.

Controls Dampening and Rebound

AMSOIL Shock Therapy Suspension Fluids are formulated to make suspension systems more predictable. The base stocks of AMSOIL Shock Therapy Suspension Fluids have inherently high viscosity indices that effectively maintain their viscosities, while their antifoam agents reduce aeration and foam.

Reduces Friction and Wear

The constant friction within a shock body decreases suspension performance. AMSOIL Shock Therapy Suspension Fluid contains friction modifiers to reduce the energy loss caused by friction, while antiwear agents are added to protect shocks and forks from premature wear.

AMSOIL STL #5 Replaces The Following Lubricants:

  • Spectro SPL Ultra Light
  • Ohlins Front Fork #5
  • Race Tech Light
  • Klotz 5W
  • Maxima Shock Fluid
  • RydeFX
  • Silkolene Pro RSF
  • Golden Spectro Very Light
  • Belray Fork 5W
  • Bilstein Bilmst 3030
  • Redline Light
  • SLP Light
  • PJ1 Fork Oil
  • Showa SS05
  • Belray HVI 5W

AMSOIL STL #5 Is Recommended For Applications Specifying The Following:

  • Denison HF-0, HF-1, HF-2
  • Lee Norse 100-1
  • Ford M6C-32
  • BF Goodrich 0152 (except PM 500 Series)
  • Racine Variable Vane Pump
  • DIN 51524 Part 2
  • Afnor E 48-603


AMSOIL Shock Therapy Suspension Fluids are recommended for front forks and shocks on snowmobiles, motocross and cruiser motorcycles, ATVs and other racing and recreational use vehicles, as well as cars and trucks that require their suspension systems to perform in the most extreme conditions. It is recommended the fluid be agitated before use.

AMSOIL Shock Therapy Suspension Fluid is available in two different viscosities.

AMSOIL Shock Therapy Suspension Fluid Light #5 (STL) is recommended for, but not limited to, Showa®, Kayaba®, Bilstein®, RydeFX®, Penske®, WP® forks, RACETECH® (US1) and Custom Axis® suspension systems. Use Shock Therapy Light #5 where less dampening and quicker rebounds are desired. It is also the preferred choice for winter use.

AMSOIL Shock Therapy Suspension Fluid Medium #10 (STM) is recommended for, but not limited to, Ohlin®, FOX®, RACETECH®, (US2), Koni®, WP® shocks and Harley-Davidson® forks that recommend type "E" or "B" fork oil. Use Shock Therapy Medium #10 where more dampening control and slower rebounds are desired.

Health & Safety

This product is not expected to cause health concerns when used for the intended application and according to the recommendations in the Material Safety Data Sheet (MSDS). An MSDS is available upon request at 715-392-7101 or on our website. Keep out of the reach of children. Don't pollute. Return used oil to collection centers.

Typical Technical Properties
Viscosity @ 100°C, cSt (ASTM D-445) 4.4
Viscosity @ 40°C, cSt (ASTM D-445) 15.7
Viscosity Index (ASTM D-2270) 210
Flash Point °C (°F) (COC) (ASTM D-92) 175 [347]
Pour Point °C (°F) (COC) (ASTM D-97) -54 [-60]
Four Ball Wear, 75°C, 1200 rpm, 40kg, 1 hour (ASTM D-4172B) 0.40
Foam, ml (ASTM D-892) Sequence I, II, III 65/0, 60/0, 65/0
Blender Test (25°C, low speed, 1 min.) 2.5 mins to settle, 8% foam

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