oil smell

[sixtwo]

Have a 93 4x4 Silverado, 350, 5 speed manual, 110k miles. Sometimes it smells like oil (gear oil?) in the cab, especially when driving for more than an hour. The engine doesn't seem to leak anywhere. 4x4 works. It happens whether or not the fan is on. No other problems. Any ideas?

 

[JollyGreen]

When was the last time the rear axle or front diff fluid was changed? It could be either getting really hot or has broken down to the point where it's no longer useful.