[Fhunter1]

Hello all,

This is my first winter with a 1981 446 and so far I am pleased with it in terms of pushing snow with the 54 inch blade. Clearing the driveway takes about 1/3 of the time it did with the old Simplicity mower. :trink:

Since we have only had a few snows here in SE Michigan I am just getting the hang of using the Case and have 2 questions regarding the plow. First my "shoes" were completley worn off when I got the blade so I picked up a used set and I am getting ready to mount them. What is the best way to set the height on these? I have a paver drive that has some crown if that maters here. Any tips are appreciated before I go to trial and error.

The 2nd issue I have seen is related to the hydraulics and might explain the shoe and blade wear. In reading some of the manuals and such it seems that I should have to depress the lever to move it from "nuetral" to raise raise/lower. Additionally the lever will not remain in the float postion if I do not hold it in postion. Is the detent for nuetral and float in the "console" linkage or TCV? I've looked in the console and nothing there is obvious, of course everything is tight fit in there and it would be easy to overlook something.

Thanks in advance for any insight.

 

[Hydriv]

The purpose of the shoes is to keep the cutting edge elevated. The blade will not clean a dead flat surface 100 percent bare. Wherever you set the shoe height, that's how much snow will be left. If you don't want your pavers to be scratched by the cutting edge, then you must set the shoe height so that the edge is in the air. However, you say that your drive is crowned. If the blade bridges the crown, then cutting edge will ride on the crowned area and mark it anyway. The solution to that problem is to remove the shoes completely and sandwich a rubber edge between the blade and the existing cutting edge. Longer bolts will be needed along with strips from a horse-stall mat or rubber conveyor belting.

On the right side of your steering wheel is the lever that controls the mid-lift cylinder. Pulling it downward, causes the implement to lift off the ground. Pushing it upward causes the implement to lower. Not touching the lever, places it in neutral. Pushing the lever all the way up as far as it can go SHOULD put the lift cylinder into "float" position and the lever should stay put if everything is working correctly. However, it is not unusual for moisture to get into the housing that looks after the float feature and ruin it.

To better understand what I'm talking about, you need to get the serial number off of your 446 and then go to the Parts Manual section of the Library here. Select Onan Powered tractors and then use you serial number to find the correct Parts Manual for your tractor. Go through the pages and find the exploded diagram of the travel/lift valve. On the back side of the SPOOL that controls the up and down of the implement lift, you will see a metal rod that goes into that spool. There is an aluminum housing that we call a "dunce cap" for lack of a better description and it fits over the metal rod. Spring loaded ball bearings press against the rod and fall into a "detent" when the spool is pushed into the float position.

Do not confuse neutral with float. Float allows the oil in the bottom and top of the cylinder to move freely back and forth that allows the blade to go up and down with no interference from the lift system. Neutral does not allow such fluid movement. Neutral keeps whatever fluid is in the top and bottom exactly where it is. That's why you can lift the front wheels of the tractor off the ground and they will stay there even when you allow the lever to return to neutral. So to answer your question succinctly, float is part and parcel with the travel/lift valve. It's a pain in the butt to work on with the valve in the tractor but it's also a pain in the butt to remove the valve. Personally, I will take PITA #2 because with the valve out and on the bench, I can service it properly .

 

[Snotrocket]

Plowing will be a pain without the float position. You want the blade to move up and down with the contours in the ground you're plowing. If you leave it in neutral and start to ascend a hill or go down one your plow will not follow the contours of the ground .

You can buy used TCV valves on ebay or quite possibly from members here to fix your float problem. Then rebuild your original TCV and uses it as a spare.

 

[Fhunter1]

Thank you for the quick replies.

It appears the float function does work if I hold the lever in the float positon. Not easy to do as I start running out of hands quickly between the travel, lift and steering. :lol:

I pulled the part manual as reccomended and I think I figured out which piece is the dunce cap ( not what I expected it to look like BTW). I'll need to pull the TCV valve when it gets to be better weather so I can pull one of my toys out of the garage

What should I look for and what parts should I expect to replace / clean etc or should I rebuild the entire unit?

Thanks in advance

 

[Snotrocket]

If you look in the parts manual you will see the exploded diagram. Inside the end are a spring and some ball bearings that form an indent on the shaft inside the TCV.

 

[Fhunter1]

Looks like a bolt / spring and ball on each side. Any seals or sealant to be used on the dunce cap or just pull the bolts rather than the dunce cap?

 

[Hydriv]

The bolts are actually hollow. The spring and ball bearing reside inside them. The usual procedure is to carefully remove each bolt and then account for the ball and spring. Then, remove the dunce cap. If everything is rusty, then it needs cleaning up to remove all the rust. If the springs are trashed, replace them. If the balls are rusty, replace them. If the spool detent rod is badly rusted, then replace it too. This is a job you only want to do ONCE. Naturally, you put the dunce cap back on first and then install the bolts with the spring and ball after, one at a time. You need to check that neither of the balls are loose inside the dunce cap and then test the operation of the float position several times before putting the valve back in the tractor.

 

[jbadman]

Looks like a bolt / spring and ball on each side. Any seals or sealant to be used on the dunce cap or just pull the bolts rather than the dunce cap?

Your comment struck a nerve, lol...Was remembering a time when the lift control spool would not allow a full float feature because the detent spool that is screwed into it (item 11 in the parts explode), under the cap, could back out partially and mislocate the spool causing all kinds of problems. It sounds like your detent spool is ok, but if you're going to disassemble the cap, springs, and balls it might be a good idea to inspect the detent spool for galling or wear on the track the balls ride in, and... see if the detent spool has actually loosened up from the main lift spool. A remedy for this, was back in the 70's from Case, was to thoroughly clean the detent spool threads with Loctite prep cleaner to remove oil traces for a clean surface, and then use a drop or two of blue Loctite on the threads on reassembly. Blue is the only one you should use. Never use red Loctite. It is very strong and requires heat to soften it on disassembly which heat is not tolerable on any hyd spool. Clear Loctite is pipe leak sealant and not strong enough to maintain a clamp load on the threads. Only use blue. It allows the next disass'y with tools (which we hope you don't have to do again), but maintains the tightening torque on assy. Loctite works in the void of air, so once you tighten the spool, it sets up and hardens with some time. The detent spool has a screwdriver head for tightening, I didn't find a torque specification but with a properly sized screwdriver head to fit it, you get all the torque you need along with the Loctite for insurance. Don't force the screwdriver twisting, you could actually break the detent.