You are here:

Small Engines (Lawn Mowers, etc.)/John Deere LX172 blade disengaging


When I am mowing over rough terrain or hit a bump, my blade will disengage.  If I turn off the PTO switch and then re-engage the blade it works fine until I hit another bump.  Could this be the adjustment of the PTO clutch?

Some clutches are adjustable.

Could it be a dirty or poor electrical connection?

Make sure you dis-connect the battery cables and clean the battery terminals and cable ends with a wirebrush or sandpaper.  Those clutches can draw some current so a dirty connection, even it it looks clean, can cause problems...I've fixed a lot of weird electric problems just by cleaning the battery connections.

John Deere use several modules in their electrical systems and rarely offer service manuals to the public...they keep the info for JD dealers only. One of the modules could be at fault but I would dis-connect each module and the clutch connector and re-connect.  Sometimes this will clean/provide a better connection...I've found a few poor connections over the years.

Do you have a digital mutltimeter?

Did you check Google or the JD message boards to see if anyone else has had this problem?

Small Engines (Lawn Mowers, etc.)

All Answers

Answers by Expert:

Ask Experts


Eric A. Jones


Lawnmower Repair . Certified Master Service Technician from B&S. Have 23 years experience on B&S, Lawn Chief, Weed Eater, Echo, Peerless, Wheel Horse, Snapper, Atlas, MTD, McCulloch, Homelite and many other numerous brands. Specialize in electrical repair.


Born and raised in the midwest. Started tinkering with engines when I was about 14 on my Suzuki RM-80. I began lawn mower repair at a small hardware store. I knew absolutely nothing. I read lots of repair manuals and met an older fellow who taught me many lessons. I continued working on small engines through high school and paid my way through college working on mowers at the same hardware store. Decided to get away from the midwest and mower repair so I joined the Air Force. I repaired air traffic control electronic equipment and ended up in Hawaii where I got a part time job at Small Engine Clinic. I gained a lot of experience from the Small Engine Clinic and had a blast repairing small engines. I then took the Briggs and Stratton Master Service Technician test and earned my MST. I then traveled to Wisconsin where I attended the factory update training seminar and received formal training. Continued working on mowers part time as I completed 20 years of military. Retired from the military on a Friday and continued in the lawn and garden industry the next Monday.

MAS Aerospace Operations BA Mathematics AAS Electronic Communications AAS Electronic Technology

©2016 All rights reserved.