The 2002 Isuzu Trooper uses Dexron III automatic transmission fluid (ATF) in its automatic transmission and GL-4 75W-90 gear oil in its manual transmission. The exact specification depends on which transmission your vehicle has, so always verify with the owner's manual or a dealership.
Automatic transmission fluid (for the automatic transmission)
If your Trooper is equipped with the automatic transmission, these are the typical recommendations and compatibility notes owners should consider.
- Dexron III ATF is the standard specification for the 2002 automatic transmission in most Trooper configurations.
- Some references note Dexron VI compatibility in newer fluids, but Isuzu manuals for this era commonly specify Dexron III or Dexron III/Mercon compatibility. Always verify for your exact transmission code.
- Using the recommended ATF helps ensure smooth shifting and proper lubrication of the valve bodies, clutches, and seals.
For certainty, consult your owner's manual or contact an Isuzu dealer to confirm the exact ATF specification for your VIN and transmission code.
Manual transmission fluid (for the manual transmission)
If your Trooper uses the five‑speed manual transmission, the fluid is a GL-4 rated gear oil with a viscosity around 75W-90. This protects the synchronizers and bearings under typical driving conditions.
- GL-4 75W-90 gear oil is the commonly recommended grade for the Trooper’s manual transaxle from this era.
- Some drivers opt for synthetic GL-4 75W-90 for improved high‑temperature performance, though always ensure the product carries the GL-4 rating.
- Always verify the exact specification for your manual transmission code in the owner's manual or service bulletin before purchasing.
Using the correct manual transmission fluid helps maintain smooth gear engagement and prolongs the life of synchronizers and bearings.
Summary
Bottom line: For a 2002 Isuzu Trooper, use Dexron III ATF in the automatic transmission and GL-4 75W-90 gear oil in the manual transmission. Always verify the exact requirement for your vehicle’s transmission code via the owner’s manual or a dealership.