Having had my coach for 3+ years and not knowing the condition of the bearings I need to have them inspected and insure they are good to go. That being said, I spoke with one of the GMC suppliers / service centers today. I asked if they inspected my wheel bearings and found they needed to be repaired or replaced would they add the zerk grease fittings. Their answer was a definitive NO. Their reasoning was that that there is a tendency for owners to over grease the bearings resulting in grease being thrown all over making a terrible mess.
What are the pros and cons of adding zeks to the wheel bearings? And does the group favor wheel bearings with or without the zerks?

Thanks for you thoughts and comments

Are the grooves in the race or the spacer?
Terry

Groves are in the spacers NOT in the races or bearings. I'm surprised that a vendor would tell you that adding the zirk to the front knuckle would not be good. Even if you do overdue it with grease, the worse that extra grease can do is splatter on the undercarriage and knuckle...just adding to the anticorrosion. By installing zirks on the knuckles, along with groves or drilling holes in the spacer, you eliminate the need to take the knuckles part every 25K miles. Each time you take those knuckles apart, and press the races out then back in, you do more damage to the knuckle. The only inconvenient part of the operation is having to loosen the axle nut, remove the front wheel, and push the axle in before applying grease. If you don't do this, the hydraulic pressure of the grease going in will displace the inner seal. By pushing the axle in, it allows the excess grease to exit the knuckle between the minor diameter of the axle and the seal, therefore not displacing the seal. IMO, if you are going to take the knuckles/bearings apart, do it right once, and don't worry about it for the next 100K. JMHO

Larry wrote on Thu, 29 January 2015 14:47

Groves are in the spacers NOT in the races or bearings. I'm surprised that a vendor would tell you that adding the zirk to the front knuckle would not be good. Even if you do overdue it with grease, the worse that extra grease can do is splatter on the undercarriage and knuckle...just adding to the anticorrosion. By installing zirks on the knuckles, along with groves or drilling holes in the spacer, you eliminate the need to take the knuckles part every 25K miles. Each time you take those knuckles apart, and press the races out then back in, you do more damage to the knuckle. The only inconvenient part of the operation is having to loosen the axle nut, remove the front wheel, and push the axle in before applying grease. If you don't do this, the hydraulic pressure of the grease going in will displace the inner seal. By pushing the axle in, it allows the excess grease to exit the knuckle between the minor diameter of the axle and the seal, therefore not displacing the seal. IMO, if you are going to take the knuckles/bearings apart, do it right once, and don't worry about it for the next 100K. JMHO

Larry,

By and large, I agree. Grease is always cheaper than parts.
Maybe the vendor that advised against has seen too many seals blown out with a grease gun.
The real purpose of the seal on a rolling bearing is not to keep the grease in, that is easy, but it is to keep the other stuff out.
I discovered as a result of an operator caused failure that most people don't know that a grease gun - your typical hand held grease gun - is usually good for 10,000 psi. There is no normal grease seal that can stand up to that.

I am hoping to zerks in my front hubs soon.

Matt