FREQUENT QUESTIONS, HELPFUL ANSWERS
Have a question concerning your Thern product? Chances are it has been asked before. Below are helpful answers to many of our most frequently asked questions. If the answer you are looking for is not provided below, please contact us!
Where can I obtain parts for my Thern winch or davit crane?
Service parts can be obtained directly from the Thern factory by contacting Thern Customer Service at 800-843-7648.
Where can I obtain repair service for my Thern winch or davit crane?
Please contact the Thern Customer Service Department at 800-843-7648 with all repair and service inquiries. Our Customer Service Representatives will determine the best course of action to be taken to repair your winch or crane.
What is the warranty policy on my Thern winch or davit crane?
All Thern products carry a two-year limited warranty. Thern, Inc. warrants its products against defects in material or workmanship for two years from the original date of purchase.
What is the importance of underwinding compared to overwinding the wire rope on my winch?
The importance of underwound compared to overwound wire rope depends on the winch being used, and it is most important when a brake is incorporated into the winch. Hand winches with disc brakes only hold the load in one direction. The same holds true for the internal brakes used on 477 and 4WP2 series power winches as well as the band brake on TA Series air winches. This means that running any of these winches with the wire rope wound incorrectly will cause the winch to work against the brake. This could cause the brake to function improperly which could allow the load to fall. It will also cause premature wear on the brakes. Prolonged use of overwound wire rope on Series 477 power winches will also cause internal failure to the reducer (gearbox), and the frame of a hand winches will flex far less with underwound wire rope.
How does the friction disc brake on my Thern hand winch operate?
Click here for a complete explanation.
Can I convert a ratchet/pawl style Thern spur gear hand winch to include a disc brake assembly?
Due to the substantial amount of difference between the components used in these two styles of spur gear hand winches, it is not cost effective to do this type of conversion.
What type of lubricant is used in the reducer (gearbox) of my Thern Series 4WP2 power winch? And what is the capacity?
The reducer on the 4WP2 Series holds 44 oz. of Mobilgear 630 or Mobilgear 600 XP 220 gear oil.
What type of lubricant is used in the reducer (gearbox) of my Thern Series 477 power winch? And what is the capacity?
The reducer on the 477 Series holds 92 oz. of Mobilgear 630 or Mobilgear 600 XP 220 gear oil.
What type of lubricant is used in the reducer (gearbox) on my Thern 4WS1M, 3M, or 6M Series power winch? What is the capacity?
Click here to view the reducer lubrication information.
What type of lubricant is used in the reducer (gearbox) on my Thern 4WS9M, 16M, or 26M Series power winch? What is the capacity?
Click here to view the reducer lubrication information.
What type of lubricant is used in the reducer (gearbox) on my Thern 4HS, 4HWF, or 4HPF Series power winch? What is the capacity?
Click here to view the reducer lubrication information.
Can I convert my Thern TA Series air winch from manual band brake operation to automatic band brake operation?
Please consult with Thern, Inc. for approval before attempting this conversion. Any conversion attempted without Thern’s approval will alter the finished product from its original design and could void the warranty.
How do I drain and refill the oil in the reducer (gearbox) on my Thern TA Series air winch?
Click here for complete instructions.
How do I drain and refill the oil in the air motor on my Thern TA Series air winch?
Click here for complete instructions.
What type of lubricant is used in the reducer (gearbox) on my Thern TA Series air winch? What is the capacity?
Click here to view the reducer lubrication table.
What type of lubricant is used in the air motor on my Thern TA Series air winch? What is the capacity?
Click here to view the motor lubrication table.
What is causing my Thern Series 477 power winch to make a grinding noise? The noise seems to be coming from the reducer (gearbox).
Nearly all failures reported with this symptom have failed due to the wire rope being overwound rather than underwound. Overwinding the wire rope forces the worm shaft in the reducer up into the bottom of the motor adapter plate, and over time the large helical gear on top of the worm gear wears into the adapter plate. This misalignment will cause premature failure of the upper bearing and other related components.
