I saw something where a guy drill and tapped a hub on a 4x4 to add a zerk.. and I have a 94 dually 2wd.. so it’s the hub rotor as one piece.. so I’ve gotten all the parts to replace the hub/rotor assembly-bearing-seal-calipers and pads on both sides and as wide as these hubs are I have been seriously considering drilling and tapping threads in each hub as far toward the inner most part of it (without getting too close to the inner bearing race) so I could pop the grease cap off once a year or so and pump new grease through the hub without blowing the seals out and keeping fresh clean grease in them.. anyone have any concerns or reasons I shouldn’t?

 

I'm not sure the bearings will use much grease. If the seals are intact and highway speeds are obtained the grease should stay in the outer portion of the bearing as designed. Unless you are slinging grease out of the seal area I would think this would be an unnecessary modification....too much grease could cause problems also....

 

well I know that some trailer axles have a zerk right in the center of the spindle to periodically grease and I’ve seen some trailer hubs with a zerk on the back side of the hub close to the rear seal.. not sure how too much grease could be an issue since the bearings and hub gets filled with grease any way. Would this be over kill? Probably.. but being able to add new grease into the assembly here and there would help keep the bearings in tip top shape for many many years. I just didn’t know if this had been done and caused issues, such as compromising the hub in any way..

 

To much grease will cause the bearings to run hot[sounds wrong but is true].

 

sorry for the late reply.. thanks for the advise.. I figured since I had seen zerks in spindles and hubs for trailers bearings, that this would be no different..so I suppose I won’t be doing it! Any advice on packing the bearings then? I’ve always packed the bearing themselves full by hand..and obviously a film on the races. But I’ve also always put as much grease as I could inside the hub..

 

Just like everything else on the planet, grease absorbs heat with friction, and expands accordingly...But with heat it also becomes thinner and more fluid...Heat expansion and lowered viscosity will eventually push it beyond the seal's retentive ability, and into the surrounding area...My advice?...Pack the bearings exactly as you described, but stop short of all the extra wasted grease...Do this on a regular scheduled basis, and you'll have fewer problems......Ben