Typical parts replaced during a 4WD log book service include engine oil, oil filter, air filter and cabin filter. Depending on the service interval, items like fuel filters, transfer case oil, differential oils and spark plugs may also be scheduled for replacement.

In a 4WD, the front and rear differentials experience extra strain, especially in off-road or towing conditions. Replacing differential oil prevents premature gear wear, overheating and metal contamination, which helps maintain smooth and reliable power delivery to the wheels.

Yes. A 4WD log book service includes checks on driveline components such as the transfer case, front and rear diffs, CV boots, universal joints, suspension bushes and wheel bearings. These parts undergo more stress in 4WD vehicles, so manufacturer-scheduled inspections are more detailed.

Symptoms include clunking noises when changing gears, whining or humming while driving, vibrations under acceleration or difficulty engaging 4WD modes. These can indicate worn gears, low diff oil or failing universal joints.

Common symptoms include grinding noises, delayed or failed engagement of 4H/4L, fluid leaks or shuddering during tight turns. These issues often point to worn chain components, low fluid, or internal wear that needs attention.