After hours, pour some biodiesel into the backhoe's tank. Biodiesel exhaust isn't as "bad" as diesel exhaust, so prolonged subjection to it shouldn't be that bad.

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'81 MB 300SD, '82 MB 300D Turbo (sold/RIP), '04 Lincoln Town Car Ultimate

Sooner or later every car falls apart, ours does it later!
-German Narrator in a MB Promotion Film about the then brand new W123.