2010 Rear Diff Oil

[Shuswap]

My local mechanic claims there is water intrusion in the rear diff because of the color of the fluid. This happened last year as well and our dealer replaced the axle seals under warranty. This time my local mechanic re-routed the vent tube away from the rear wheel well splash area thinking that may be the cause. The service manager at my dealership says the vent is under positive pressure and wouldn't allow water intrusion. He also says it is unlikely there is water in the diff.

I've searched to see if water intrusion in the rear diff is a common problem and found nothing to indicate this is so. Do any of you have experience with this? The truck has 60,000 kms (36,000 miles).

 

[IZwack]

FWIW, it is not under "positive pressure" or else it would need a source for that pressure. Thermal expansion of the gas (and to some extent, the fluid) in the differential of course does occur but this does not produce a constant positive pressure over hours of driving.