How to Add Grease to Super Lube Trailer Hub with Rear Grease Zerk Fitting

Question:

If the hub has a grease fitting on the back, do you still use the bearing buddy grease fitting or do you add more grease from the grease fitting on the back of the hub and fill until grease comes out of bearing buddy?

asked by: Rick T

Expert Reply:

The rear side of a Super Lube hub has a grease zerk fitting that works like the one on a Bearing Buddy grease cap such as # BB1781. These zerk fittings let you add wheel bearing grease to the hub interior without having to remove it from the spindle.

The claimed advantage of the Super Lube hub is that the rear zerk fitting gives you the same grease fill convenience as a Bearing Buddy but without the risk of blowing out the rear grease seal from the pressure of pumping in too much grease. Since the hub's rear zerk feeds grease in an outward direction toward the dust cap (or Bearing Buddy) the idea is that this method of adding grease will be less likely to damage the seal, which WILL require you to remove the hub to replace the seal.

When you fill your hubs from the rear zerk you will want to have the grease cap removed or at least loosened so that old/excess grease can be pushed out. This way you can easily remove it once you see the hub bore has been filled with fresh grease. With this type of hub you can safely use standard grease caps.

expert reply by: Adam R

Georgiepoo

8/12/2020

Bearing buddies work great for short haul to put-in where axle will be under water for launching, but for a long haul one needs to check the bearing by feel occasionally for overheating. With the zirk in a buddy and keeping the hub filled with grease protects the bearings from salt water but risks popping the seal out the back. No easy answer, even with hand packed hubs I feel for overheating when traveling.