Somewhere in the Sunline manual you should find a list of everything that Sunline installed in your unit. It'll have the refrigerator, stove, hot water heater, radio, converter, and so on. Included in that list should be your axles. They should be listed by manufacturer, model number, serial number, and type. That should get you pointed in the right direction to identifying your bearing type.
Also, you may find valuable reference information at www.dexteraxle.com
that will help in identifying your axles and then in maintaining them.
If you don't find the axle info in your Sunline manual, post a pic of them here. It would be helpful if you remove a wheel and any decorative stuff like plastic hub covers before you take the pic. I am sure that one of us can identify what you have there.
Axles that need hand-packing should be done annually at a minimum; more often in high mileage situations.
'12 F250 4x4 Super Duty PowerStroke 6.7 diesel
2011 to present: '11 Cougar 326MKS
1999 to 2011: '99 Sunline T-2453
Amateur Radio kd2iat monitoring 146.52