It's recommended that trailer hubs be pulled and the bearings and races cleaned and inspected and the bearings repacked every 12 months or 12,000 miles.
Assuming you're speaking of an EZ Lube spindle, I'd recommend checking the grease fill monthly. Attach your grease gun such as # L30-310 to the zerk fitting and gently apply pressure until you see the outer bearing move or see grease oozing through the outer bearing. Being too forceful and adding too much grease too quickly can blow out... view full answer...
The 9519336 is the same as the # DM9519336 and the 9599006 is the same as the # SM99251. The price for these and all of our products can be found on the product page. We do not carry the 9523157. If you want custom wiring you can use the Curt # C96JR or if you want to stick with Demco you can use the universal # DM9523010-54. view full answer...