Hi Snowbirds,
The Heartland Trailer manual has a pretty long maintenance checklist. The appliance manuals also typically have a maintenance section. All of these manuals should have come with your Bighorn. If you're missing any, we have an extensive collection of manufacturer manuals on the forum. Click on the TOOLS tab at top of page and select HOM - Heartland Owners Manuals, or use
this link.
For maintenance on axles and brakes (assuming you have Dexter components), the manuals
here should help.
If you want to put it all together into a single maintenance checklist, we can post it to the forum to help others.