Gear Coupling Repair & Rebuild - What You Need to Know

Even with lubrication, gear couplings involve tooth-to-tooth (generally metal-on-metal) contact that gradually will wear down the gear teeth. This wearing phenomenon is not unique to gear couplings... and in gearing applications such as gear boxes, who industries have been built around gear repair, rebuild, and replacement.

As such, it would be natural to wonder if worn gear couplings could be repaired or rebuilt... and, if so, what exactly that looks like.

(Being a leading gear coupling manufacturer, this is certainly a question that we are presented with on a regular basis... and are very well prepared to answer.)

To quickly cut to the chase and answer this question as briefly as possible... Yes. Gear coupling components from a given manufacturer generally have interchangeable parts that can be replaced on an as-needed basis. Seals and gaskets can be replaced. Lubrication can be changed out, and, if necessary gear coupling sleeves and hubs can be interchanged. 

Flanged "F Type" Gear Coupling

Elaborating just a bit... it is important to note that if a gear coupling hub or sleeve is changed out (giving it new gear teeth), the corresponding hub or sleeve should also be changed out (so as not to have worn teeth engaging with new "fresh teeth"). This logic means that it is acceptable to replace on half of an "F Type" flanged style gear coupling (replacing both the hub and sleeve on one side), while leaving the other side as the original. 

Bonus Tip #1: Because "C Type" continuous sleeve gear couplings make use of a common sleeve that would be new to both hubs, these type couplings are generally not suited to be changed out as a "half couplings".

Bonus Tip #2: If and when changing out a flanged "F Type" gear coupling half coupling (with new hub and sleeve on one side), it is critical that you ensure the bolt pattern matches up to the bolt pattern of the original manufacturer. As a standard, Lovejoy, and many other North American manufacturers adhere to a common bolt pattern standard that holds true through generally a size 9 gear coupling (AGMA 9008-B00: Flexible Couplings -- Gear Type -- Flange Dimensions, Inch Series).

Continuous "C Type" Gear Coupling

Bonus Tip #3: If mixing and matching flanged "F Type" gear coupling halves between two different manufacturers, it is also important to ensure that both manufacturers' products meet the required application's bore and torque requirements. (Common AGMA flange bolt patterns does not mean equivalent torque and bore ratings, and should always be checked.)

Bonus Tip #4: Prior to replacing any gear coupling, it is always worthwhile to inspect and understand how and why the coupling is wearing. Gear couplings often provide signature wearing patterns that can help alert you to potential issues (i.e. - excessive misalignment) that should be addressed to prior to re-starting a system. (The following article provides a number of great photos to help analysis gear coupling wear: Gear Coupling Tutorial - Part V: Failure Analysis (with photos).)

Final Tip: We (Lovejoy) have been selling our legendary Sier-Bath gear couplings for decades, and recently released our cutting edge HercuFlex gear coupling product line. Our engineers are world class, and we know the gear coupling marketplace and the solutions available down cold. Should you have any question or need regarding gear couplings (bolt patterns, interchanges, application recommendations, etc.)... please do not hesitate to reach out to us. We take tremendous pride in being a solutions oriented organization, and look forward to helping you and your business in the very near future.