Transmission service is per freightliner. Look in their manual at service page and be sure to look for correct category...RV. The manuals are written for heavier service like trucks. I think first service is around 15,000 but I could be wrong.
Egg smell. Haven't heard this one before. Have had weird smells when dealers spill oil and other fluids on hot exhaust during dealer prep. My Palazzo came with gross overfill on transmission fluid so it overflowed everywhere when expanding with heat. Dummies can't read a dip stick.
Possible smell is grey/black tanks if roof vents are drafting wrong way, which is possible when strong down winds blow down vent pipes. Forces sewer gasses into coach drains instead of escaping out vent. There are 3rd party vent cap improvements available at most rv stores. Pretty easy to install.
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