Robs Stupid Lawnmower Page
This is Robs Stupid Lawnmower Page. It is Stupid.
Sep 15, 2003 Guess what? I found another car that is tired of being a car!!
The idea of using a car motor for a gocart is an awesome idea, but building a car out of a car is just silly. Thats what I ended up doing on my cart page.
A picture of the victim... I mean donor car.
Stupid little 1.5L motor
Im thinking this will turn out alot better than the previous one. Start off with a good sized 4 cylinder motor, put the motor in right, instead of goofy sideways, use a solid rear axle to get the gearing down to enable adding big back tires, and put it on a small, light frame.
This time I will call it a lawnmower instead of a gocart.
A front wheel drive drivetrain has an extra stage of gear reduction in the transaxle to slow the speed down enough to connect directly to the tires. Connecting the output from the transaxle to a normal rear axle gives another stage of gear reduction.
The axle I am using has a gear ratio of 4.27 to 1, which has the effect of lowering the top speed of the vehicle exactly 4.27 times. Since I have much larger tires than originally installed on the car, the top speed is reduced only about 3 times. For example, if the cars tires would have spun at 120mph at redline in top gear, now it would only be able to go 40mph. This may seem like a huge compromise, but 40mph is really fast for a lawnmower, and chopping down the top speed by a factor of 3 has the effect of tripling the torque.
I spent a few hours getting the car running before ripping the drivetrain out. It was missing sparkplug wires, fuel lines, battery, and a few other things, but didnt take too long to figure out how to get it going. Carb is kinda poopy, but may be because of the fuel line mess. Bottom line is that it runs.
Well, I just happened to have a cart left over with a trashed motor, and is way over built for the 350cc motor it has in it. Cart without a motor, meet motor without a cart. I also happened to have a couple of axles that came out of my 68 Scout.
After buying a new battery, and a trip to the junkyard for some rims and tires, it looks like I have all the pieces I need.
A couple days later, and it is coming together already.
Ok, it doesnt exactly roll yet, but the motor is mounted, all non-essential wiring and vacuum lines have been yanked off, battery and a few things have been wired up.
The hardest part was stripping off all the extra wiring, and trying to make sense of the 500 vacuum lines. I had a feeling that since the carb had 50 vacuum lines to it, it would never run right unless I had something to hook to all of them. It also has several electric lines on it.
I just happened to have a much simpler nearly new Holley 2bbl carb that came off my Scout when it got a motor upgrade. The Holley carb has much larger barrels and they are spaced quite a bit farther apart than the goofy one, but If I could make an adapter to make it fit, I would be in business. I just took 2 pieces of plate steel, and welded a couple pieces of 1 inch tubing between them a an angle to get the holes to line up.
My stupid carb adapter helped simplify the wiring and vacuum system.
Now that it runs fairly well, it needs exhaust and a muffler. The exhaust on the car used to curve under the motor from the manifold. I cut the bent pieces, turned them, hooked them together and into a pipe and muffler that was on the motorcycle motor that was on this frame when it was a gocart. It turned out looking pretty decent, is quiet, and makes alot of low end torque
Cute little motorcycle exhaust on a car motor.
Sep 22, 2003 It has been a week now, it runs great, I have gotten most of the critical items done. It has exhaust, muffler, can be started with a key, the rear of the frame imbellished to mount the axle, driveshaft connected, etc.
Driveshaft looks cool too.
Since I am only using 1 of the driveshafts from the transaxle, and the transaxle isnt posi, the unconnected transaxle output would spin freely as soon as any resistance is applied to the connected end. Making a second driveshaft with the end welded to the frame solved the problem and doubled the top speed with a net result of reducing the torque multiplication to 1.5. Unfortunately, I dont have a picture of the other driveshaft.
It is driveable now, but steering didnt work out like I had planned and currently uses a couple of ropes on a bar. I will think of something soon to replace it, but at least I can drive it around.
Putting around in the back yard, it was running kinda warm, figured it was time to hook up the cooling fan to come on when it gets warm.
Overall, looks mostly done, but still a bit to do.
Sep 26, 2003 I finally got a seat and a real steering wheel on it, mounted the shifter from the car, and some other little things like a dash cluster with working speedo and tach, and some paint
Now I can tell how fast the motor and wheels are going.
Quite a bit better now that I can steer.
October 7, 2003 After driving it for awhile, I realized it was pretty cool, except the steering was just too stiff. I played with several ideas for the steering, but finally decided to simply use the rack and pinion unit from the car. It would give the reduction to make it take several turns of the steering wheel to steer sharply, which would make it easier to steer overall. The rack is a power unit, but Im not going to hook it up right away. If it is still not easy enough, I can make it power steering later.
Looks like it was born there.
You are probably wondering why I have a differential bolted to the front of the frame over the steering. It is intended to be a PTO like device to power the lawnmower blade and later a snowblower, but Im still working on that, so youll have to wait for the details.
Now that it is easy enough to steer, it is kinda fun to drive around the back yard, but still cant do anything special. I decided it was time to put on a trailer hitch. I just happened to have one laying around
Now it should be able to do something useful.
To test the trailer hitch, I hooked up to my trailer that has the car on it. It worked very good, is plenty strong enough, and mower has plenty of power to pull it uphill through soft stuff.
Here it is pulling its old carcass around on a trailer.
October 21, 2003 When you are bored and stupid, you sit around thinking of goofy things to do. Well, I had a transmission in the garage that I wanted to put in the barn. The tranny is heavy, and I dont have an easy way to carry the thing that far. Being stupid, I figured that I could pick it up with the cherry picker and push it all the way to the barn, but the cherry picker has small wheels and is kinda hard for a lazy stupid person to push. I figured I could tow the cherry picker behind the lawnmower, but it would be hard to make sharp corners, and the small wheels would still get caught on cracks in the sidewalk.
Hmmmm, what to do? What if I made a bracket to attach the cherry picker to the lawnmower that keeps it off the ground. It would solve the sharp corner and the small wheel issue in one shot. I threw something together real quick to carry it around.
Hows that for stupid?
An 80mph lawnmower is just silly, but it worked just fine until I was driving to my neighbors house at a high rate of speed. Since it doesnt have any brakes, I use the shifter to slow me down. I accidentally downshifted into 1st, instead of 2nd, and the back tires nearly stopped while I was still going about 40. The lawnmower slid around a bunch, and hopped and bucked and ended up breaking the idle driveshaft loose from the frame.
I wasnt planning on driving my lawnmower 80mph, and figured doubling the torque couldnt be a bad idea. I removed the drivetrain so I could disasemble the transaxle to weld the differential and remove the need for the idle driveshaft
Wow!! Doubling the torque again made a huge difference, and I wont miss the top speed. Most of the time I only go 10-15mph anyway. Doubling it again probably wouldnt hurt, but by my calculations, I am getting nearly 20000 (yes 20 thousand) foot pounds of torque to the back tires!!!
January 4, 2004 I have mostly just using the lawnmower to pull sleds through the snow in the back yard. It has no trouble pulling several people and/or several sleds through the slippy stuff. It is also fun just to romp through the snow.
Mower is a real workhorse, but fun playing in the snow too!!
April 02, 2004 The dash gauges didnt last very long. The front suspension from the ATV was way too wimpy for bouncing a car motor around. I modified the frame to support the cars original struts, spindles, and hubs, then bolted the cars front rims onto it. This should work alot better.
Mower is has a much beefier front suspension now
In the picture above, the brackets on the front that the rope is connected to were for mounting the lawnmower blade. The vehicle was built with the sole idea of being a lawnmower, but a 100hp motor powering a blade meant for a 12hp motor didnt last very long.
The main problem with mowing really fast is that when the mower is moving forward at a high rate of speed, the left side of the blade (that moves forward) liquefies the grass since the speed difference between the grass and the blade is much too high. This wouldnt be much of a problem by itself, but there is a bigger problem with the other side of the blade. The right side of the blade cuts as it moves backwards, and is way too slow to cut effectively. Doubling the blade speed to about 7000 rpm helped the marginal cutting problem, but made the liquefied grass problem much worse.
I would have liked to have pictures of the green paste flying out of the grass chute, but you can probably imagine how stupid it was, and the pasty grass clogged the blade housing and the grass chute very quickly.
The blade and the bearings just couldnt handle the power of spinning so much faster than it was designed for. There is alot of vibration at 7000rpm, and way too much torque for the relatively wimpy blade.
Jun 12, 2005 I know, it has been a long time since I have posted anything about my stupid lawnmower. Truth is, I was having too much fun to take pictures. It has been my strongest helper for nearly 2 years now.
Last summer I taught it how to scoop up dirt to put some place else. Moving dirt was easy compared to moving all the snow last winter. Yes, that is a 55 gallon drum on the front in the picture below :)
You can see the reinforcement on the top outside of the barrel. The inside has 5/8 inch bar on 3 sides and a 1.5 inch pipe connected to a 3/8 inch thick steel plate as a blade!
The linkage between the lawnmower frame and bucket is hinged at each end. The hinge at the bucket end allows the bucket to tilt. The hinge at the frame allows the bucket to be raised and lowered. The angle of the linkage allows the bucket to raise itself up to dump when the tilt chain is loosened and the lawnmower is driven forwards. Pretty stupid huh?
Mower can scoop up snow and dirt now too!
The chain on the top left corner of the bucket is for tilting the bucket up after filling with dirt. The strap on the winch was plenty long enough to connect to the bucket, but stretched too much when scraping up dirt. Ask me how much it hurts when the chain breaks and flies back towards the driver and hits him in the knee!!!
Mower can scoop up snow and dirt now too!
I also taught it how to dig trenches for sprinkler pipe. The vertical bar to the right of the seat rotates the shaft that raises and lowers the light blue frame. The thing between the frame and right rear tire that looks like a rear sprocket from a motorcycle is really a rear sprocket from a motorcycle. There is a second, spring-loaded rod that keeps a length of chain pressed against the teeth of the sprocket to keep it from rotating until the driver wants to adjust the height of the digging.
You can almost see the small plow blade underneath that is covered in grass. The 6 inch by 2 foot long piece of 1/2 inch thick steel pivots on the blue frame to set the angle of the plow for the most efficient trenching. With this setup, the lawnmower can dig a trench almost 2 feet deep. It only removes about 6 inches of dirt from the trench, but breaking up the dirt is most of the work. I have used the lawnmower to dig almost 1/4 mile of trench for sprinkler pipe and wiring now!!
Mower can dig trenches too!
Aug 7, 2006 The little bucket just wasnt cutting it. I wont bore you to death trying to explain why a bucket needs to be as wide or wider than the vehicle it is mounted to, but I needed a bigger bucket.
I had a REALLY heavy old cast iron bathtub laying around, and for some reason, I decided it would make a good bucket if I cut the front of it off and turned it around.
Would anybody in their right mind think to use THIS for moving dirt?
Mower can scoop up MORE snow and dirt now!
I have also used it as a huge, self propelled wheelbarrow. It can hold nearly a ton of concrete. It is difficult to steer with a full load of concrete in the bucket, but Ill get over it.
Here it is getting ready to be loaded with concrete chunks
Ok, who DOESNT need a 100hp ladder?
I borrowed the hydraulic ram from my cherry picker to control the height and digging angle for the bucket.
Some better pics of the bathtub bucket
A closeup of the bucket linkage
Since the new bucket was about twice as wide as the old one, it took about twice as much power to to cut into the dirt to pick it up. The power wasnt a problem, but cutting into the dirt forces the front end down, which simultaneously forces the rear end up. Not a good thing when you need alot of traction.
I found the best method for moving packed dirt was to use the plow on the back to break up the dirt, then scoop it up after it was loosened. but I grew tired of this rather quickly. The narrow plow didnt break up much dirt at a time, and got partially packed back down after making several passes. My solution to buy a scraper thing to help break up a much wider swath of dirt at a time.
This should break up dirt much faster than the little plow!
The dirt scraper thing was made for a tractor with a 3 point hitch, and mine obviously didnt have one. Instead of modifying the scraper or just welding some goofy brackets, I made a generic 3 pt hitch for my tractor. This is actually revision 2, since the original one only allowed up and down adjustment.
A bit more complicated than I had planned
The scraper thing worked great for breaking up a nice wide swath of earth at a time. It is pretty good at moving and levelling dirt too. It takes quite a bit more power to pull dirt along the ground than it does to carry it, but it levels the dirt out as it is dumped, and power is not a thing that my stupid lawnmower lacks. It just takes a bit more gasoline.
In addition to the necessary up and down movement, rev 2 allows tilting front to back, and side to side, independently. I had an electric scissor jack to raise and lower the scraper for awhile, but it was just too wimpy, and didnt last very long.
August 15, 2006 Having the scraper on the back greatly increased the amount of traction when digging up dirt. It increased it so much that when I found a piece of buried concrete with the corner of the bucket while aggresively trying to dig up dirt, that it broke the bucket completely off of the brackets I had welded to it. It took 2 BIG chunks out of the bottom of the tub and cracked the rest of it nearly in half! Since the bathtub was cast iron, it is not reliably weldable, so it is ruined.
I spent some time on the computer, designing the ultimate bucket for my stupid lawmower. I was pretty excited about having a bucket that could hold about half a cubic yard of stuff. Once I got a quote for the steel that it would take to make it, I wasnt excited anymore. I didnt realize how expensive steel had gotten since my last big steel purchase.
September 01, 2006 I was on my way to the store, and saw some used front end loader buckets for sale on the side of the road. I turned around really quick and bought one for about the same price as the steel would have cost to make my own!!
Looks almost like a real tractor
The original linkage between the bucket and the frame was fine for the smaller buckets, but this one is almost twice as much volume as the bathtub, so it can be twice as heavy. The new bucket being that far out in front of the lawnmower made the back tires come off the ground when the bucket was full!! To decrease the leverage against the lawnmowers weight, I shortened the linkage between the bucket and the frame. Now I can fill the bucket with half a cubic yard of concrete, and still be able to drive.
With the extra weight that the bucket can handle, cranking the winch to lift the bucket was getting really difficult when it was completely full. I replaced the chain and strap with a cable and put a pulley on the bucket arm to double the leverage.
Having the bucket closer to the the frame makes it able to handle more weight, but makes for an interesting ride when it comes time to dump.
The front tires come off the ground when dumping out the bucket.
As you can imagine, this puts alot of stress on the front wheels. I actually broke the front wheels off a couple times when dumping the bucket. After reinforcing the front end a bit, I havent had any more problems.
Apr 02, 2007 My Stupid Lawnmowers duties have evolved quite a bit since I originally designed it. When I decided to use an old gocart frame, the intended purpose was for the machine to mow grass. Since then, it has proved itself useful in hauling around several tons of dirt and concrete, but bouncing around on rough ground while carrying a couple tons of dirt in the bucket is way too stressful for the relatively wimpy frame. I have repeatedely broke parts off the frame due to stress cracking. Since the main part of the frame is drastically undersized, adding extra reinforcement only postpones the cracking.
Also, the front tires are not made to support the massive amounts of weight. They are rated at 1200lbs each, which means the front end can only support 2400 lbs. Since the bucket can hold about 2 tons of stuff, when you add in the weight of the lawnmower itself, the front tires have been carrying about twice their rated capacity. It wouldnt bother me to exceed the ratings, but it has the nasty side effect of popping the tires off the rims when carrying lots of weight and hitting a bump just right. It is time to go back to the drawing board.
Since I need much larger tires to support the weight of a full bucket, it seems to make sense that I should use the same size tires as the old lawnmower had on the back. Since the tires will be all the same size this time around, I might as well make it 4WD. There has been several times that I have needed 4WD. The easiest way to get 4WD and greater capacity would be to use a solid axle in the front this time.
Using 2 solid axles, and 4WD, it makes sense that I would need to connect both axles to the motor. What better way than a transfer case that is made for just this purpose? Now I just have to figure the best way to connect these components together in a way that will be solid enough to handle the demands I will be placing on it. How about part of a truck frame?
OK, maybe I didnt think of all this from a requirements standpoint. It just happens that a friend of mine had a 4x4 truck without a body or motor that he was trying to get rid of. Seems like an excellent bunch of pieces to make version 2 of my stupid lawnmower out of. Thanks Marc!
There are alot of extra pieces on a truck that wont be needed on a lawnmower. Springs for instance are a bad idea when you want to carry huge loads around. Think what would happen when trying to lift the bucket off the ground if the front end had 6 inches of travel. The bucket wouldnt start to lift until the springs compressed considerably, making for lots of extra work. It would also make grading a flat area almost impossible as the springs extend and compress over evey bump.
I used the front half of the frame for the whole lawnmower. I only used half because I wanted to keep the wheelbase short to make maneuvering easier, but I used the front half because the frame is narrower in the front, which allows the tires to steer sharply without hitting the frame.
View from what will be the left front
View from front
Closeup of the drivetrain
View from the rear
The pics show the axles welded to the frame, and the transfer case mounted fairly solid. The rear axle is connected directly to the transfer case with a ujoint, instead of having a driveshaft. The front driveshaft is connected as well. Now all I need is some POWER!!
Apr 08, 2007 It has come time to yank the drivetrain out of the old mower and figure out how to hook it to the new frame. The lawnmower and I have spent so much time together in the past years it kinda makes me sad to be ripping apart my strongest and most faithful helper when it still mostly works. Oh well, here goes...
Ripping the motor out of the old lawnmower
Not much left of the old mower without a motor
You can see how wimpy the frame is now that the motor has been removed. The frame was originally made for a 125cc gocart. Pretty awesome that it lasted this long, but it is time for an upgrade.
New mower has a motor!!!
New mower has a motor!!!
Motor looks wonderful in its new frame. Small problem though. Ive heard that sometimes stupid people design stuff without doing any measuring whatsoever, and sometimes they end up with a transfer case that is a couple inches too far to the left, and not lining up with the transaxle output when the the alternator and exhaust are crammed all the way against the frame!!
Same pic, with driveshaft in red, transfer case in blue, alternator in yellow, and exhaust in green
Same pic with highlights.
The motor assembly needs to move a couple inches to the left to get the red and blue areas to line up, so Im gonna have to cut out part of the frame to make room to scoot the motor over to get things to line up.
You cant see it in this pic, the transaxle and the front ujoint are touching, so moving the alternator and exhaust wouldnt help.
Apr 15, 2007 I got the frame modified, motor mounted, some crazy radiator hoses, and added steering and a seat. It is driveable now!!
A whole weekend of welding made it driveable!
A whole weekend of welding made it driveable!
A whole weekend of welding made it driveable!
A whole weekend of welding made it driveable!
4WD wasnt as impressive as I thought it would be, since the axles have open differentials. Driving 1 tire over a substantial bump makes one of the front tires and one of the rear tires spin in the air, making it stop completely. I decided to weld the front differential to enable posi in the front end. Having the front axle locked helped the 4WD capbility enormously, but makes turning very difficult. Not only is it difficult to turn, it tries to return to going in a straight line. With the front hubs unlocked, it is pretty easy to steer, but I may have to add power steering once I start carrying heavy loads around.
It is time for the stupid thing to start doing some work. I cut the 3 point hitch parts off the old mower, and made places to weld them onto. It turned out alot better the 3rd time. Version 2 required dropping the scraper on the ground to to adjust the left to right angle. It involved changing which part of the chain was bolted to the lift arms. It was very cumbersome. I bought some adjustable lift links several months ago, but the lift arms were too close to the drag links. Now it works great
Mower can pull the scraper now
Vertical blue arms are for setting the angle
Apr 23, 2007 The scraper works great now. It could be much better, since the seat is in a stupid place now, and I still have a hard time adjusting the height of the scraper while I drive. Traction is way better than it was before, allowing me to get a full scraper every time.
I got so excited at how well the scraper worked, I quickly made the attachment points for the front bucket. In 2WD, it worked a bit better than it did with the old mower, since I had lower range which allowed steadier application of power.
Scoops up about the same amount of dirt in 2WD
Locking the hubs made a dramatic difference!! When the bucket starts to fill, the front end gets very heavy, which lightens the rear end, and rear wheel drive hits a limit to how much the bucket can fill. With all the weight on the front end, traction isnt an issue when you are driving the front wheels.
Scoops up WAY more dirt in 4WD!!
Half a bucket load left on the ground
Front tire is a bit stressed at 10psi
Dumps completely now too!
Aug 09, 2009 Its been almost 6 years since I built my Stupid Lawnmower. The motor was tired when I installed it, and it has worn out several carburetors. It hasnt ran right for several months, probably due to a worn intake valve. I could have rebuilt the motor, but I really wanted to have fuel injection for winter.
I just happened to have a 1990 Geo Prism that has a fuel injected motor that wont pass emissions because the EGR valve. The EGR valve costs more than the car is worth to me.
Stupid little car waiting to be victimized
Had to modify the frame a bit again
Having a fuel injected motor is a huge bonus, but I knew that it was gonna take alot of wires to control everything, and was gonna be tough to get the computer and all the extra stuff wired up correctly. Turns out there are TONS of wires!!
Lots of wires!!
I took nearly all of the wiring harness from the car, with the exception of the ones for the turn signals, headlights and stuff, just to make sure I had everything to make it work.
Even the gas tank and fuel pump are different on a fuel injected car to supply higher pressure for the injectors. You can see I used the original tank and pump to get it going the first time.
After I got it to start, I started unplugging wires and clipping ones I thought it didnt need. After each group of wires was cut, I attempted to start it, to make sure that it still worked before chopping the next group.
There was one huge bundle of wires that I cut that prevented it from starting after I cut it!! Tearing apart the wiring that I removed revealed that one wire went a ways down the harness, and looped back to connect to something else. Connecting the ends of the 2 wires together at the cut point fixed the problem and once again started and ran. Whew!!
I was able to remove a huge portion of the wiring without affecting the motor. I found a nice place by the transfer case to put the fuse box, and got some longer cables for the battery, and mounted it on the other side of the transfer case.
Wires a bit more tidy
Now that the wires are cleaned up, I needed a better setup for fuel supply. Strapping the original tank to the front of the mower worked fine for test drive, but was way too large and didnt fit well. After test fitting some other car gas tanks, that were all too big, including one from a Karman Ghia, my wife came up with the idea of modifying an old air compressor tank!! I happened to have a 7 gallon tank that I wasnt using, so I chopped a hole in the end and modified the cars fuel pump to fit the new tank.
Stupid gas tank
One interesting challenge I faced, was that the alternator wanted to occupy the same space as the frame. Removing the AC compressor and modifying the alternator mount a little, enabled me to turn the alternator towards the ground instead of up. I made a silly little tensioner for the new angle and the original belt fit perfect. I had to lengthen 4 wires that go to the alternator, but wiring is easy.
Ugly little alternator tensioner
I had modified the transmission on the old motor to make both the driveshafts spin together, but for quickness on the new lawnmower, I just welded a piece of pipe from the idle driveshaft holder to the frame. It didnt last very long, partially because the driveshaft holder was a strange material that didnt weld very easy, and partially because the new motor has alot more low end torque than the old one. The additional torque kept ripping the pipe and breaking the welds!
Kept ripping the idle driveshaft
To modify the differential on the old lawnmower motor, I had to remove the tranny and separate the differential from the tranny to get to the gears to weld them. The Toyota trans has a convenient little removeable cover over the differential that enabled me to weld up the gears without removing the tranny!
Ugly welds on the differential
Now that mower is mostly functional, its time to see what it can do. I decided to post videos this time, cause still pictures dont really tell the whole story.
Video going fast (for a stupid lawnmower) (8MB)
Video showing power (10MB)
Theres kindof a tradition around here, where we mutilate the donor car after getting all the parts off it that we need. This particular donor car had been flipped over a few times to get parts off it, like the gas tank, and stuff. There is still plenty more damage to be done to the poor little car
Video pushing car (3MB)
Video tipping car over (7MB)
Video rolling car (20MB)
Video tipping back on wheels (7MB)
Pushing and rolling car over is kinda fun, but I came up with something a bit more destructive. Wonder what happens if you hook an old basketball post to the back of a 100hp lawnmower?
Video (6MB) Wonder whats gonna happen?
Making spear a little sharper
Video (23MB) Hypodermic needle version
Video (25MB) Yet again
Video (21MB) Stab N Tip
Oct 2, 2009 The fuel injected motor works way better than the old carbureted one. It has considerably more power in the low rpm range than the other one had. Only problem is that it broke the front bucket off AGAIN.
The bucket setup has been needing to be improved for quite awhile, but it is a big job to do it right. The arms need to be quite long to allow raising the bucket more than a foot or so off the ground.
Making really long arms that can handle 27000ftlbs of torque is no small feat they have to be incredibly strong, especially the part that bends towards the ground.
Here's how it turned out
Looks almost like a tractor now
Looks almost like a tractor now
Arms are about 7 foot long now, and are made from 3x3 1/4 inch thick angle iron. I boxed in the arms, so it took about 50ft of angle iron to make and weighs about 200lbs! You can see from the photos that it seems to be strong enough
I still dont have a way to raise or lower the bucket. There are chains between the bucket end of the arms and the lawnmower frame to support the weight. In the meantime, I need to raise the bucket one more notch to get a better digging angle and make it dump easier.
Eventually, I plan on installing hydraulics to raise the bucket. I just dont want to spend a million dollars and make my lawnmower too complicated.
Jul 27, 2011 Nearly 2 years ago, shortly after adding the new bucket support arms, I smeared the differential in the back axle. I figured the axle was gonna die a spectacular death from being vastly overpowered, but as I was digging semi-normally, there was a little pop sound, and the front tires started peeling out excessively. Thats when I noticed the back tires were locked up and being dragged along by the front tires.
Switching from forward to reverse repeatedly several times got the rear tires turning normally again, but werent supplying any power to the ground. Looks like the differential finally died a fairly quiet death.
Over the past year or so, I havent even opened the differential to check inside. It has been getting worse and worse, to the point when I was using it to move a load of dirt, it was very difficult to get a bucketfull of dirt with the back tires locked up solid, and reversing didnt make them unlock anymore. Looks like Im finally gonna have to dig into it and see whats going on.
The pinion keeps trying to pop out whenever it manages to try and help
Apr 22, 2012 I finally got around to pulling differential apart and its like I suspected. Totally destroyed. It appears the front pinion bearing came apart and popped the pinion nut off. The threads on the end of the pinion are destroyed. Without the pinion bearings, it just ground itself to death and mutilated the diff carrier. Gonna have to get a whole new axle.
Not much left of the front pinion bearing
Pinion hiding inside the case. Threads are jacked
Gobs of differential dust in the cover
Pinion ground diff carrier enough to be useless
Even with the whole thing tore apart, the pinion still catches on the diff case, and stops the rear axle from turning. Sad thing is, even if I pull the axles from the axle housing, there isnt enough room to remove the diff housing and ring gear, so I gotta cut the axle off before it will roll normally again.
As long as Im cutting the axle off, I might as well replace it, and I dont have anything laying around to replace it with. Was kinda hoping to make it roll in 2wd temporarily, but not gonna happen.
May 01,2013 I finally found a new axle for my stupid lawnmower!! It is a Sterling 10.5 inch thats normally used in dumptrucks and some heavy duty RVs.
I really liked the short wheelbase the lawnmower had, but the differential on this one is several inches longer than the other one, so I had to stretch the frame. I figured while I was at it, I would make room for a driveshaft with a stretchy part in it to allow for flex without stressing the pinion bearing, which may have been a factor in the other axles death.
The shortest driveshaft I could make with a slidy part was about a foot long
Really short driveshaft, but much longer than ujoint
Rear frame looks really weak now
There was a couple issues with the back wheels. If I remember right, the lugnuts wouldnt tighten down all the way with just a single wheel.
I dont remember what was up with this.
I think I had to add some washers between the wheels and axle to get the lugnuts to hold the wheel securely. Besides the lugnut issue, I dont think they were the right wheels for the axle. With the wheels turned in, they bound up on the brake drum. Removing the brake drum allowed turning the wheels around though.
Jul 20, 2014 It has been over a year since I swapped out the rear axle. I fully meant to box in the rear frame better to make it stronger, but having a little more flex in the frame has proven to be a good thing for keeping all four wheels on the ground as much as possible. I havent worked it really hard, but it has dragged quite a bit of dirt with the scraper and moved a few buckets of dirt around. I really do need a floor though.
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