3/6/2013 2:03 PM
We used to run 721XRs all year long for about 9 years. They are great mowers, but yes, wheel bearings go bad. First and foremost, make for sure the locknut that loads the bearing is not wore out and loosens up because this will cause even the slightest of play and will cause bearing to go bad fast. Then you should look at your grease, what type of grease. We use wheel bearing grease and we were greasing the wheels if not every day, then every other day. When we grease them, I would have the mechanic put just enough grease in them till it would just start coming out at the axle. We had a guy at one time that thought 2 pumps, 1 time a week was greasing the wheels and spindles, the mower was in the shop more then it was out mowing replacing bearings. Also make for all the spacers and axles are in good shape and you may have to replace every couple years. I did have one wheel that went thru a set of bearing quickly and found out that the axle bolt had a slight bow to it.
We moved on to a John Deere 1620 with a Lastec 425 deck on it and love it, but we still use the 721XR as a backup or catchup when it rains. The 1620 does not leave the clumps like the 721XR does in the wet grass. We had one unit that did not have discharge chutes and the clumping was greatly reduced.
Paul L Double
Golf Course Superintendent
Sugar Valley Golf Club
Bellbrook, Ohio