Here’s a fairly straight forward service job that comes up from time to time. We were on a service call to a local tree farm and one of the tasks to perform on this ‘out of shop’ service call was the replacement of the tines on this 60″ Kubota tiller.
Our client saved us a little time by removing the unit from his tractor and even removed the old worn blades. So with half the job all ready done, we got busy and replaced the tiller blades.
Not all Tines Created Equal
The blades are marked ‘LH’ and ‘RH’ indicating the direction in which the blades curves off from the shaft. If you divide your tines into LH and RH piles it makes the whole process a lot easier.
Find and Use Correct Hardware
The hardware used to install the blades is sometimes a little difficult to locate if you’re looking outside dealership avenues. The bolt is a grade 5 designed to ‘shear’ if the blade becomes locked or engaged on something very solid like a rock or buried root. The nut and lock washer are metric and fine thread. The nut fits directly into the stub on the rototiller shaft, so only a socket is required to turn the bolt. Do not use an off-the-shelf local hardware nut and bolt that is not the exact metric fit. If you do, you’ll rototill about 10 feet and all your tines will have disengaged themselves from the shaft.
The most important thing to remember if you undertake replacing these yourself is to ensure that blades are installed opposing each other. Simply start at one end and work your way toward the other, alternating LH and RH tines. If it looks like our photo here you’ve got it right. We install 32 tines onto this 60″ tiller in about 20 minutes.
We also took the time to adjust the chain case tensioner, recommended by Kubota after every 50 hours of service. If you’re like most owners, 50 hours of ‘seat time’ rototilling is a lot. Figure it this way – if you rototill every spring for an hour, and then every fall the same you’ll only have to service that tensioner once in 25 years, so not that often at all.
Inspect Gear Case
The rototiller gear case, where the PTO shaft attaches to on the rototiller, holds 80W90 gear oil, the same as the differential in your pickup truck. This particular rototiller has a dipstick. Pull it at the beginning of the season and check for level. Most often these rototillers gain water in their differentials from condensate. If you notice cloudy, milky oil, then flush it and replace it with fresh stuff.
Changing Oil in Side Case
If you are going to change the oil in that side case, plan on having a whole Sunday to kill. You will need to remove all 60 bolts to get a look at the adjuster shoe that maintains some tension on that chain drive. There is a spring tensioner in there as well but we find that really does not do a whole lot.
Loosen off the set nut on the chain adjuster and back the adjuster off slightly, then tighten the adjuster down. You will feel it get tight real fast as the chain does not stretch a lot so it does not take much to take the slack out. After taking the slack out, run the set nut back down to hold the adjuster in place.
Lubing is done on the PTO shaft. Make sure the universal joints are greased, tight and that the PTO shaft is well lubricated so it plunges and contracts easily. You cannot really over-do the lube here! Lay it on!
Our after pictures shows a fully serviced Kubota RS1351 Rototiller that’s been lubed, had the oil topped up, the tensioner checked and of course 32 brand new tiller tines. It’s kinda nice to get out of the shop once in a while for a field trip!
Service Department Vic