I decided I wanted a garden tractor to help out in the back yard and possibly blow some snow. We used to have a 446 on our farm so I spent many hours riding around cutting grass. That 446 had thrown a rod and my Dad swapped in a Vanguard which worked great but didn't really fit in that great my Dad said.
So I searched around for a 446 that was a fixer upper when this emerged from its green hiding place.
This is the tear down phase, sand blasting, pressure washing. painting in behind the motor.
Previous owner said the starter was seized and couldn't start. It also had 2 inches of water in one of the cylinders for a very long time and pitted the cylinder. After running it with the snow caster a few times I would get this weird oil burning event and it sounded like it was going to break. So time to tear the engine apart too.
Two different piston rods, it was spinning the front main bearing, lots of rod bearing play, lots of play in the bores. just a tired old engine.
This Is all a recap of the winter work but maybe it will help somebody. It is my favorite thing to take things apart, rebuilt, paint, reassemble. Learning about how they engineered it, how points work, how hydraulics work. And compared to cars its pretty cheap.
I haven't ever rebuilt a motor completely before so I wanted to take a crack at it. Right from the start I went down the wrong path. I measured things with a caliper and it looked pretty good so I ordered some parts from ebay and onanparts.com
The motor had one old rod that was really out of shape and a newer style rod that was useable. I ordered new rings and bought a hone. I honed it until the pits were out of the cylinder walls. when i put the stock pistons with new rings back in they looked so sloppy in the bores I had to check what the piston cylinder clearance should be. I ended up ordering scratch and dent pistons from onan parts with rings that were .010 over and I honed the crap out of it until i got the clearance to spec. Not recommended
I bought a micrometer ( good idea ) and saw that the crank was out of round on the rod journals. I asked a machinist about getting me out of this mess but he didn't want to get involved understandably. So I figured I'll do it myself like they did in the old days. I sanded it with emery cloth and sized the rods by sanding down the cap to get my clearance good with plasigauge. It took a few weeks of saying oh thats good enough and then sanding some more the next day.
The main bearing was also worn on the crank so it probably should have a .010 undersized but thats not what I ordered and it was just over spec. so in it went. The main had spun in the block, the block was a little worn with the new bearing so I roughed up the block with a punch where the bearing presses in to shrink it down. Froze the bearing in dry ice, covered the bearing bore with JB weld and tapped it in.
In hind sight I should have bought a micrometer and checked everything first. sent the crank off for machining and ordered parts after I knew what I had, but I didn't. so as it sits today it runs well. I pulled the heads to check for any sloppiness in the rods and it all seems pretty good. I will run it this summer and see if it needs a proper rebuild in the fall. Nothing more money can't solve.
I'm a big subaru fan so any horizontally opposed engine is a friend of mine.
As I was waiting for parts I stripped and painted the hood. I used rattle can power red and clear coated with a two part clear coat. I have learned that I can't let the rattle can paint dry or it will react with the clear coat and wrinkle it. I like clear coats because I can wet sand and buff all my mistakes. I also find the rattle can paint so fragile
Fenders are PPG single stage Farm fan Orange. $60 for a quart + catalyst + activator but it is crazy tough paint and I've painted the fenders and the deck with 2/3 quart. I sit on the fender when I get off the tractor and it hasn't scratched the f
I installed an oil pressure gauge that taps into the oil plug on the side of the block. There is a big empty space in there where the oil filter will go in the next generation block.
Next step was the loader build. sounded easy enough but what a ton of welding, fabrication and money. I think it cost about 1100 in material maybe more but I took it out for a test run and never looked back.
The idea was to have it removable so I could "easily" detach it and switch to snow blowing or mowing. There are two brackets that bolt on to the side of the frame and then the loader drops onto two pegs on the end of these brackets. the front support hooks into the attachment pins. the oil feed comes off of the rear pto. It is way too fast for my liking. 2 x 1.5" cylinders moves the boom up 4' in about 1 second at fast idle.
If anybody has any Ideas to either slow flow or modify the hydraulic spool to make it a smoother transition so I can feather it a little better. I think it's a crappy Princess auto valve that is half the problem.
The mower was next. It looks like somebody drove full speed into a tree stump so the blade actually cut through the front of the deck.
Strip the paint. Narrowed the deck as much as possible because of my gate to the back yard so I cut the discharge chute off and made a hinge so it can flip up. Cut the wheel assembly mounting points and moved them inward so basically the blades are the widest part and wheels tuck in behind the deck.
New bearings in the spindles, cleaned up the pulleys. I rebuilt one of the pulleys in the mule drive by grinding the rivets off, separating the two halves of the pulley, replacing the bearing and plug welding the pulley back together. I find these replacement pulleys so expensive, seems like a rip off for two stamped steel pieces and a Chinese bearing.
There's a pick of the loader removed. Going to be fun to put it back on but it needs a few mods here and there and then paint.
That's about it right now. There are some headlights in the mail $$$
I've been having good luck spraying rattle can power red, let is get set up and then a good quality rattle can clear coat. Gives it a good shine and more durable finish.
The one thing I have been lucky about was I was given a box of parts and I was only missing 2 heat shields out of all that mess so I thank the previous owner for keeping those in a pile for me.
I had a leaky valve cover gasket this summer that caused a lot of grass and dust to accumulate on my engine, creating heat issues. I was short on time, so I took it to the local lawn and garden shop...