Tech Tip #48: Maintaining Your Rockford and Twin Disc Power Takeoff Clutch

Dr. Diesel
Written by Dr. Diesel


Keeping your Rockford or Twin Disc® over-center clutch in good operating condition is easy if you know these guidelines. This Foley Tech Tip will show you how to check your clutch for adjustment, how to adjust it, and how to keep it lubricated.

When to Adjust Your Twin Disc or Rockford PTO

The key to maintaining your clutch is knowing when to adjust it. Monitor the force necessary to engage your clutch. If the pressure required to engage it drops 10-15%, your clutch facings are wearing and your Twin Disc/Rockford PTO needs adjustment.

How to Monitor Engagement Force

Recently, Foley field service people have developed an easy method to measure engagement force if your engagement lever does not have the appropriate socket fitting.  We weld a socket onto one end of the cross shaft and use a torque wrench. This technique is so simple that it can be done as part of your daily maintenance. The chart below tells you when it is time to adjust your Twin Disc or Rockford PTO.

Clutch Size Engagement Force Must Adjust At:
8″ 65-72 ft. lbs. 55 ft. lbs.
10″ 101-108 ft. lbs. 85 ft. lbs.
11 1/2″ 108-115 ft. lbs. 91 ft. lbs.

How to Adjust Your Clutch

Here are the steps to take: Disengage the clutch, remove the inspection plate, and rotate the clutch to gain access to the adjusting ring lock. Then remove the lock bolt and adjustment lock. Rotate the adjusting ring counterclockwise to lighten the clutch. Then adjust to obtain the proper handle engagement force. When done, reposition the locking finger in a slot and tighten the adjustment lock bolt.

Lubricating Your Clutch

Use lithium base #2 grease prior to installation of your PTO. Grease the release bearings (if not sealed), the main bearings (rotate the shaft by hand until the grease comes out), and the cross shaft. Once a PTO is installed, follow this schedule below.

Lubrication Schedule

Bronze Release Bearings Daily
Main Bearings Every 100 hours
PTO Cross Shaft Every 500 hours
Linkage and Levers Use SAE 30 synthetic every 500 hours

Finally, don’t over-grease.  In our experience – and we sell on service more than 300 PTOs a year, over-greasing a Twin Disc/Rockford PTO is the leading cause of failure.

Please call us with any questions about your over-center or spring-loaded PTO. Foley Engines stocks new and remanufactured units, clutch packs, facings, and other maintenance parts. If in doubt about your Twin Disc / Rockford PTO, call us. We take tech support seriously and want to advance the knowledge base in the power transmission field.

Manufacturer’s names, symbols, and numbers are for reference purposes only and do not imply manufacturing origin.


Dr. Diesel
Written by Dr. Diesel
Knowledge is power. Power to build ties to engine users. To build a relationship with our customers, we share with you our 105 years of knowledge in many ways. We have this special section called “Ask Dr. Diesel™” where you can pose questions about engines, transmissions, industrial hand clutches, exhaust scrubbers, etc.