Your 2363 has "E-Z Lube" bearings which means the bearings can be re-packed without removing the wheels. Just remove the plastic hub cover (assuming you have the steel wheels), find the grease fitting, remove the dust plug from the fitting, and use a standard grease gun to repack the bearings. This will repack both outside and inside bearings. Just keep pumping the new grease in. while slowly spinning the wheel (which means you will have to jack the side up enough to let the wheel rotate), until the grease coming out is clean. The Dexter Axle manual that came with your Sunline manual identifies grease products (by manuafacturer and type) approved for use.
I repacked the bearings on my 06 2363 last summer after a trip to Colorado, will probably repack once per year. It is very easy to do.
2004 Nissan Titan Crew LE, 4WD, Tow Package
2006 Sunline 2363, Reese Dual Cam, Prodigy