Farm Equipment Repair: How I repaired my old Simplicity Rototiller
I've mentioned several times on our web pages that I use a rear
mounted tiller on the Simplicity 7116 for preparing planting beds. A
picture of it in action is on our
This old tiller was on the tractor when I bought it from a guy in Ohio
through eBay. I have used it for several years but had to
modify it some to help it combat our rocky soil. The sheet metal guards over
the tines were always shaking loose and falling off. The threads in
the mounting bolt holes had reamed out completely on one side so I just
tack welded the guard in place.
I also mounted a piece of 2" square metal tubing (the same heavy walled stuff I used for the legs of my
across the bottom of the guards to
stiffen them. On each side of the drive and tine shafts,
there are bearing blocks bolted onto the outside of the case. The
mounting bolt holes on one side of the tine shaft had also reamed out
and would not stay tight. This allowed the tine shaft bearing on that
side to loosen and the tine would hit the guards. When I heard that
noise,I knew it was time to go back to the shop and retighten the bolts. I
tried everything I could think of to keep the bolts tight, but nothing
worked for long.
This old tiller was always very noisy but kept on
tilling so I didn't worry about it. Just like any other
problem in life, if you ignore it long enough it will force you to deal
with it. Last spring (April 08) I was tilling a new garden
bed when I heard a real nasty sound from the main casing of the
tiller. The noise suddenly went away and the
tiller quit. The drive pulley was still turning but the tines
were not. I didn't have a clue how these things worked inside the
case but when you use old equipment like this, you really have little
choice but learn to repair it yourself or trash it and try to find
another old one somewhere.
I visited the
web site to see if there was any help there. I found some diagrams for
Simplicity tillers which showed a system of drive chains on sprocket
gears inside the case. Not knowing if I could repair
it, but having nothing to lose, I tore into it. I found that my tiller has 3
roller chains instead of 2 like the diagrams I had found. The
chains and the sprockets had worn enough over the years that the slop
in the chains had allowed one of them to come off it's sprocket.
This picture shows the inside of the case after the chains were removed
and the old grease was cleaned out. The small shaft at the top is the
drive shaft and the large shaft at the bottom is where the tines mount.
I don't know how new tillers are built, but this old thing is pretty
impressive. I'm not at all surprised it lasted as long as it did.
I knew I would never find replacement sprockets, but maybe I
could fix the chains. I thought I could possibly shorten each chain by
one link and remove the slop. I have never dealt with roller chain
before so I 'd a little learning curve. It turned out that 1
whole link was too much to remove but there are offset links
available which allow you to shorten a roller chain by 1/2
link. After learning how to measure the chain to size them,
the smaller chains measure 1/2 inch between pins which corresponds to
4/8th of an inch so is designated as a #40 chain. The larger chain
measures 5/8 inch so it is a #50 chain.
While trying to find the offset links I discovered that
carries these chains as go-cart parts. The chains
come in ten foot lengths and include a master link.
The #40 chains were about $10.00 each and
the #50 was about $20.00. I wasn't sure that the chains from
Northern were the right ones and if they were, would new
chains remove enough of the slop. If it worked ,
for $40.00 I could replace the chains and forget about the offset
links in the old chains.
Here are the roller chains I purchased. There are listed in the
Northern catalogue as including a master link. As my luck
would have it, someone had removed the master link from every #50 chain the local
store had in stock and they had marked out the text on the boxes
mentioning the master link. I, of course, didn't notice and had to return
So if you need one these chains, check the box! I had to order a # 50
chain from the catalogue. Also please note that 1 ten foot section of
#40 chain is more than enough to replace the two smaller chains. You
will just need one extra master link which Northern usually carries in
As you have probably guessed, the chains worked great! This picture
shows them installed on the sprockets. The little bit of slop you see
in the top chain is because the drive shaft is leaning but will
straighten up when the other half of the case and the other bearing
block are installed.
Here the chains and sprockets have been completely covered with grease;
the assemble with the mounting bolts for the drive shaft bearing block
has been slip over the drive shaft; the top plate containing the bolt
holes for the tine shaft bearing block has been placed over the shaft.
There is a matching plate which is visible in the picture above.
These plates are separated by the spacers also visible above. Bolts go
through the casings, plates and spacers. One of these bolts also holds
the bottom hitch frame to the tiller. The 3 smaller holes around the
shaft are the ones mentioned above where the tine shaft bearing block
bolts. The threads in these holes were reamed out so I drilled and
tapped them for 7/16" bolts instead of the original 5/16"
bolts. I also messed up the gasket when I took the case apart
so I used a heavy bead of Permatex.
Here is the case back together with the bearing blocks and lock collars
in place. When the hitch frames, tines and tine guards are
installed, it is ready to go again. It's amazing how much quieter the
tiller runs with new chains. Maybe it will last another 20 years!