SEMI TRUCK DRIVETRAIN FLUIDS — GEAR OIL, TRANSMISSION & DIFFERENTIAL
Every fluid in your drivetrain has a job. Wrong viscosity in the drive axle means scored hypoid gears. Wrong spec in the Allison means failed clutch packs. These guides cover the correct fluid, the correct viscosity, the OEM approval that matters, and the drain interval you can defend at fleet audit.
Class 8 Drivetrain Fluid Guides
Each guide covers the correct fluid type, viscosity, OEM specification, and drain interval for that specific drivetrain component. Select the component you are working on.
Gear Oil — AMSOIL Severe Gear
GL-5 synthetic gear lube for axles and differentials. Full SEVERE GEAR product guide — 75W-90, 75W-110, 75W-140, and 80W-140. Drain intervals up to 500,000 miles on Class 8 line haul.
View Gear Oil Guide →Differential Oil — Drive & Steer Axle
What viscosity goes in a Class 8 drive axle vs steer axle, OEM approvals for Dana, Meritor, and Mack axles, and the full change interval table for synthetic vs conventional.
View Differential Oil Guide →Wheel Hub Oil
Wheel hub lubrication on Class 8 tandem axles is separate from the differential. Wrong fluid here causes seal failure and bearing damage before the next scheduled PM.
View Hub Oil Guide →Manual Transmission Fluid — Eaton Fuller
Eaton Fuller RTLO series manual transmission fluid spec, viscosity, and drain interval for Class 8 line haul trucks. PS-164 spec and synthetic alternatives.
View Transmission Fluid Guide →Allison Automatic Transmission Fluid
TES-295, TES-389, and TES-668 spec guide for Allison automatic transmissions in vocational trucks, buses, and Class 8 automatics. What each spec means and which AMSOIL product meets it.
View Allison ATF Guide →Commercial Fleet Accounts
ONE TRUCK OR A HUNDRED — SET UP YOUR FLEET ACCOUNT
AMSOIL commercial accounts ship direct to your yard or shop. Wholesale pricing, no minimum order, consolidated invoicing. Takes five minutes to apply.
Apply for a Fleet Account →