Symptoms
Drips under the centre of the truck, a wet transfer-case housing, low fluid at service, whine from the transfer case.
The fix, step by step
- Unbolt the affected driveshaft from the output flange (mark it for phasing), replace the output-shaft seal, inspect the flange for wear grooves and replace it if scored, then refill with Mercedes-approved transfer-case fluid.
- Clean the housing so you can spot any recurrence.
Tools & part numbers
- Output-shaft seal
- seal puller and driver
- flange holding tool
- MB-approved transfer-case fluid
- paint marker
- torque wrench
Where to buy the parts
Corteco transfer case output shaft seal, front outer (G 550 2019–2021)FCP Euro ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Mercedes-Benz G-Class (second generation) parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.