GuglioLS
Administrator
Jinma354 LE
Posts: 1,276
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Post by GuglioLS on May 20, 2010 23:26:51 GMT -5
Rich,
I'm really impressed with your one man rigging to split the beast and keep everything in alignment. What a great idea using what looks like a furniture dolly to support and the use of wood rails to guide the dolly, very clever. I hope to remember your setup when the times comes for me to do the same. So the problem all along seems to have been loose bolts?
I'm happy to hear my clutch pics, measurements and adjustment thread was helpful.
Larry
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roy697
CTW Advanced Member
Roy's Pond
Posts: 303
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Post by roy697 on May 20, 2010 23:27:48 GMT -5
Great job. Keep safe. Question-Is that a freeze plug in one of those pictures? If so I think I would do something to make sure it doesn't create a problem later by rusting thru.
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Post by Rich Waugh on May 20, 2010 23:38:05 GMT -5
No real work done on it today as I had too many other issues to deal with instead. Saturday I'm gonna get it back to being a one-piece tractor, I hope. Got a friend coming by to help with that - I don't see any good way to manage that single-handed. Not even sure four hands will be quite enough, but that's all that are available.
Thanks for the kind words, Rob. Means a lot coming from you, the guy who practically builds them from scratch in his basement. If the Chinese were as diligent as you are they corner the world market in a month.
Larry, if you do the dolly thing like I did, try to find caster wheels that are solid iron and have heavy frames - I've been really nervous that the ones I'm suing might collapse as their frames are marginal for the load. If I planned to do this more than once in my life (I damn sure don't!), I'd make some up using grooved sliding gate wheels and use angle iron for the guides - could keep it aligned to a gnat's ass that way. Thanks again for the pics!
Roy, that is indeed a core plug, I think it's the one for the camshaft bore. I've cleaned it, phosphated it and painted it with 95% zinc cold galvanizing primer and will give it a coat of black paint soon. I had a concern that it might have been leaking, but I really think that area just collects chaff from owing and that holds the water from washing and rain and caused the rust. The plug itself seems sound. Thanks for mentioning it, though. The tractor has always had SCA anti-rust coolant in it so I'm pretty sure the inside of it looks pristine. Hope so... :-)
Brad, I agree about the unfortunate state of quality control on assembly. In looking fairly critically at most of the individual components I've been handling, they generally look pretty damn good. Sure, the castings aren't finished with facing sand so they come out of the foundry smooth as a baby's butt, but they are sound castings of reasonably dense iron and that's what counts. The engine bolts have all been high grade and some of them are rolled-thread bolts, even. Black oxide instead of cheesy plating. Not bad at all. But then they take those core components and assemble them without torquing the bolts properly or getting the gaskets situated properly. They tend to use much cheesier steel and fasteners on the ancillary stuff like control linkages, too. The cotter pins they use are the stuff of bad legend - break them with your fingers. Stuff like that.
I think that a person could buy one of these tractors new, disassemble it entirely and re-assemble it critically and diligently and have a machine that would be astonishingly dependable and durable. But when the factory fails to properly tighten hidden, inaccessible and mission-critical fasteners the thing is doomed from the git-go. That is nothing more than a failure of supervision and/or quality control. It wouldn't cost a nickel more to do it correctly. Unfortunately, this seems to be a hallmark of Chinese and, to a somewhat lesser extent, Mexican and third-world manufacturing. There seems to be a sense of personal pride in craftsmanship lacking, or perhaps it is just a poor work ethic. The end result is the same - poor workmanship at the assembly level.
I see the same thing manifest itself with formerly US-made things like McCulloch chain saws, for example. They used to be dependable and then they out-sourced their assembly to Mexico and they went right in the crapper. Last night I was talking with a friend who sells and installs wireless internet systems and he told me he uses a certain brand of radios and routers that have a bad DOA rate, but...the ones that are okay out of the box will keep on ticking for damn near ever. The components inside are great, but the quality control at assembly is shabby. I'v eheard the same story from several people in manufacturing who deal with outsourcing and/or importing of products from the far east and third world countries.
What American industry needs to see and worry about is that the only thing preventing Chinese equipment from taking all the market is that one stumbling block. And they will overcome that, I'm sure. Didn't Japan all that long after WW2 to go from being the stereotype of schlock to being the epitome of perfection - just an attitude change. China is not far behind, I fear.
So now I'm in the process of doing what the factory could and should have, and when I'm done I'll have a great machine. Eat your heart out, Cyrus McCormick! (grin)
Rich
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Post by stumppuller on May 21, 2010 21:27:25 GMT -5
Rich, you've expressed every one of my exact sentiments very well. Eventually China will follow in the footsteps of Japan and Korea and upgrade their quality control to the point of producing great stuff. But this is now and these are the problems we have to deal with when we buy Chinese.
What I don't understand is why the oil is leaking, unless I am misinterpreting the exploded diagram. As I see it the rear main seal is part of the engine block. So, the seal keeps the oil in the engine and should the bell housing loosen up, oil should still be retained in the engine, no?
However, my tractor leaks oil, lots of oil at the bellhousing separation joint, so what's going on?
Bruce
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Post by Rich Waugh on May 21, 2010 23:45:33 GMT -5
Bruce, I understand your confusion on this, since I had the same problem initially. When I quit looking at the diagrams and started looking at the tractor itself I began to understand what was happening. In the car engines that I've worked on, the rear main seal is housed in the block itself, and the bell housing bolts to the block and is "dry." But in my tractor, the rear main bearing seal is housed in the flywheel housing which is, from all visual appearances, the forward half of the bell housing. In reality, the flywheel housing is essentially a bulkhead sealing the rear of the block and creating a transition to the bell housing. The top of the oil sump is partially open at the rear of the block and the flywheel housing's mating face seals the sump and also seals the rear of the crankshaft by means of the rear main bearing seal. The other functions the flywheel housing perform are that of providing a mounting point for the starter motor and providing mounting bosses when the engine is used in a stationary application. (This last I deduced form the presence of "feet" on the flywheel housing casting.) There is a thin paper gasket between the flywheel housing and the actual bell housing, but that gasket is pretty much superfluous since that whole area is dry. I would guess it serves no purpose other than to possibly absorb shock and vibration in a minuscule way. In the case of my tractor, the flywheel housing was not tightly bolted to the block, which chewed out the gasket there at the bottom. If you look immediately below the crankshaft end in this photo, you'll see a dark rectangular area. That is an opening into the top of the oil sump. Since that chewed up part of the gasket seals the top of the engine sump, oil could then flow from the sump out between the block and the flywheel housing. Which it certainly did. The bell housing did show a bit of oil at the bottom, which tells me that some oil found its way past the rear main bearing seal, but I honestly couldn't see any oil tracks on the dry side of the flywheel housing to prove that. If the rear main bearing seal was completely failed I'd expect to see the bell housing with a lot of oil all over it (slung out by the clutch and flywheel) and see it drooling out the weep hole in the bottom of the bell housing. I had neither of those symptoms. There was not more than a quarter of a teaspoon of oil in the bell housing, at the very most. Probably less. I did notice that the bell housing weep hole is tapped, by the way. I suppose one could close it off with a small bolt to prevent water from coming in when driving through deep rice paddies or fording streams. I don't do those things - I'm a gentleman farmer, not a coolie or pioneer. Sure I am. :-) Hopefully I've explained this in an understandable fashion. If I haven't, let me know and I'll probably make it more confusing. Rich
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Post by stumppuller on May 22, 2010 10:26:57 GMT -5
Rich - The information you are providing is great! I'm gaining confidence all the time now.
About gaskets.... I remember that my old MG had paper gaskets which would always leak. The thicker they were, the more they would leak over time due to compression creep. The Japanese eliminated oil leak by incorporating O-ring & groove design. Many high performance motorcyle engines used no seals or gaskets at all, but relied on liquid gasket sealer (esp. on the crankcase halves of 2-strokes).
My theory is that one can never fully torque down a casting which has any sort of thick, compiant gasket, or even a thin paper one for that matter. I intend to use liquid gasket maker on the bellhousing surface & torque it to sepc. The casting faces need to be absolutely clean before applying and the micro machining grooves serve to give "tooth" to the gasket film.
Bruce
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Post by Rich Waugh on May 22, 2010 12:01:25 GMT -5
You could probably use the liquid gasket goop on the bellhousing-to-flywheel housing surfaces with no big problems, but you could also probably leave that gasket out entirely without any major issues. That joint is not "wet", nor is there pressure differential from one side to the other so the gasket isn't there to effect a seal. Therefore, I conclude it is only for cushioning and/or clearance.
The flywheel housing-to-block gasket is definitely something that I would NOT replace with the liquid goop or just any homemade gasket. As I noted previously, the rear main seal is contained in the flywheel housing. Changing the thickness of that gasket could adversely affect the relationship of the rear seal to the crankshaft end, the relationship of the throwout bearing to clutch fingers and possibly the engagement of the transmission shaft splines to the clutch discs and/or pilot shaft to pilot bearing. The OEM gasket is right about 1mm thick, which is not insignificant when it affects mated surfaces. I'd recommend sticking with it. It does seem pretty hard and resistant to compression, although I've pitched out all the bits of the old one so I can't measure them to see what they had been crushed down to. My recollection is that they were still pretty thick and I know that the new gasket did not crush appreciably when I torqued it down. Keep in mind too, the old gasket did not fail - the improper assembly set up conditions that destroyed it. I'd strongly recommend using an OEM replacement.
Way back when I was racing dirt bikes we used to lap the heads to the cylinders to eliminate the gasket for higher compression and better heat transfer. Used a lot of liquid gasket stuff, too. But these tractors aren't race bikes.
That's my opinion, based on a (very) little knowledge of such things. Hopefully Tommy and Ronald will chime in here with some professional advice on this. They actually know what they're talking about, while I'm just deducing things from empirical evidence. Okay, I'm guessing. :-)
One thing I can say with some certainty is that if your tractor is leaking for the same reason mine was, you don't want to continue using it until you fix it properly. With those highly-stressed and critical joints loose the potential for catastrophic damage is high.
Rich
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Post by shotley on May 22, 2010 19:34:46 GMT -5
I just read the postings about the gaskets. Mine has a very small leak. What if I just tighten it up to specs and don't remove the last plate at all? I plan on doing mine in the near future but am going to school with you guys and asking all the dumb questions as I think of them. From what I can see the gasket is not damaged. I do plan to replace the bolts and washers with high strength ones. I just got back from a trip and haven't read about your splitting rig yet and will do so. Thanks everyone!
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Post by Rich Waugh on May 22, 2010 20:54:07 GMT -5
shottley,
If your tractor is leaking from the same place mine was, (the joint between the flywheel housing and the engine block), there is no way to simply tighten it up. The bolts that secure it to the block are behind the flywheel and you must split the tractor, remove the clutch assembly, remove the flywheel and then, and only then, can you access the bolts for the flywheel housing. After you've gone to that much effort, you'd have to be daft to reuse the old gasket. A new one costs less than ten bucks and replacing it gives you the opportunity to clean the mating surfaces properly, check for any manufacturing defects or burrs, etc.
Based on what I found in the way of flywheel housing bolts, there was no reason at all to replace them with anything "better." They are high-quality black oxide finish with roll-formed threads from what I could see and more than up to the task they perform. They are the flange-head type so no washers or lock washers are used, nor do they need to be. Some anaerobic thread locking compound (Loctite blue) and the housing will be better than new.
Update:
Today I girded my loins (okay, I put on some dirty shorts) and attempted to reassemble my tractor. My goofy dolly and track arrangement worked fine and it went back together with only minimal fidgeting. Of course, just as soon as I started to install the first nut on one of the studs I realized that I'd completely forgotten to install the new bell housing gasket. Shit! (Side note: this is my punishment for telling Bruce that this particular gasket doesn't really do anything and could probably be left out without causing any real problems. When will I learn to keep my big mouth shut?) Anyway, roll it back away again, put in the gasket, and then coerce it back together again. Amazingly, it went together the second time, too. A bit of Loctite on the threads and run the bolts and nuts home and torque them down. Heaved a huge sigh of relief. I'll bet my shoulders went up two inches at that point - I've been as nervous as a whore in church about this whole project, just in case you couldn't tell. :-)
One thing I can now say with some confidence is, splitting a tractor really isn't as overwhelming as it sounds when you've never done it. Now that I've actually done it, I wouldn't hesitate to do it again if it was indicated. Factor that into your anxieties if your tractor is hinting that it may need to be split someday soon. You can do it.
The time I spent at the lathe making that clutch pilot tool certainly paid off. I'll try to remember tomorrow to post the dimensions for it so you guy scan make your own. I made mine from steel because I had it, but it could just as easily be made of wood or plastic. Sure worth doing! I remember hearing something a while back about Tommy or Ronald having plans to sell them - if so, then buy one ready-made.
I discovered, while re-assembling the hydraulic lines, that I hadn't marked which ends went to which fittings, which could have been a bit of a problem on things like the steering motor. Fortunately, I took a crapload (technical term) of digital pictures as I went along and they showed me what was what. If you don't already have a digital camera, buy one before you split your tractor, and use it liberally!
All that is left to do is hook up the wiring harness, adjust the clutch assembly, install the loader towers, make new loader braces, re-fill the fluids I drained, prime the injector pump and make some brackets and guards for the hydraulic lines where they run under the tractor. I could see that mine were deformed from brush catching on them and I'd like to put a stop to that before one gets really damaged or torn loose. Likewise for some of the wiring harness. There are several places on the bottom of the bell housing, transmission and rear drive assembly where there are unused tapped holes that would be dandy spots for hanging new guard brackets. No excuse for not doing them, I guess. All of that is going to have to wait for a few weeks until after I go off-island and also finish up a couple of blacksmithing jobs.
On the issue of loader braces:
It has been noted that the forces acting on the bell housing by the loader are not in a direction that would cause the bell housing joint to open up at the bottom. I believe that is probably correct, but one force that wasn't mentioned is the direct rearward force that is applied when you ram the bucket into something. Whether it is deliberate or inadvertent, the bucket does get whacked into things from time to time. Since there are no shock absorbers in there anywhere, the force of that jolt is transmitted from the bucket through the loader arms to the loader towers. From there, it is transmitted to the bell housing mounting points. Adding braces from the loader tower tubes back to the rear axles prevents the jolt from deflecting the loader towers rearward, stressing the bell housing mounting points and the bell housing casting itself. The more you distribute a load over a greater area, the less force is applied to any one point and that's a good thing. So there. :-)
I'll update this again when I get around to doing something I can report on. I do feel confident that what I have done so far has fixed the oil leak and probably saved my tractor from imminent self-destruction. Learned a bunch in the process, too.
Thanks to all you guys, especially Tommy and Ronald, for all the advice and guidance. This is a great forum!
Rich
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Post by shotley on May 23, 2010 18:56:31 GMT -5
Rich: I have a 204 with no loader. This leads me to believe my trouble is like yours. I beleive the factory just did not tighten the bolts. I guess the only two things than make me nervous is taking the clutch off and the other seal on the end of the crank. I blanked and forgot what you call it. I have a level cement floor and good place to work on it. I have used a lot of tools but on small electronic equipment and don't consider myself a mechanic at all. I made a living with tools and they are not my hobby. I will take your advice about taking pictures of everything as my memory is so short I can't possibly get ulcers about yesterdays problems.
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Post by Rich Waugh on May 23, 2010 21:07:09 GMT -5
Well, the whole process is one that is not designed to inspire confidence in those who have never done it before, that's for sure. I was, frankly, really apprehensive. I just took it very carefully and took lots of pictures and I seem to be getting through it just fine. I'm quite sure you'll get through it okay, too. Having a level concrete floor to work on makes it way easier, and a 204 is a lot lighter and smaller than my 304. Taking the clutch off is easy - just undo the six bolts holding it on and lift it off. It comes off as a more or less complete assembly. The primary clutch disc will be loose, but the PTO clutch is retained within the clutch stack which is bolted together. The rear main bearing seal will come with the flywheel housing. To replace it you'll have to drive the old one out of the housing and then drive the new one in. It's an interference fit and I always use a bit of gasket shellac on the new one when I install it. Real mechanics, one of which I am not, use a seal driver to drive the new seal into the housing, so as not to distort it. I just cut a disc of plywood the same diameter as the seal and use that to whack on so I don't ding up the new seal. I wipe a smear of assembly grease on the sealing lips of the new seal before i slip it over the bearing when re-assembling the housing to the block. I don't use any cement or goop or anything else on the gasket itself. The only potential fly in the ointment on reassembling the tractor is getting the clutch disc aligned in the clutch when you put it back on the flywheel. You can sometimes get lucky and just eyeball it to center and get away wit hit, but I don't have good luck with that so I use a clutch pilot tool. I made one for the 304 clutch but the one for your tractor will probably be different. Mine looks like this: The steps on it correspond to the pilot bearing, PTO clutch disc splines and main clutch splines, plus a couple inches for a handle. You slip the clutch disc into place and put the tool through then set the clutch stack on the flywheel and begin tightening the bolts. Give the pilot tool a little jiggle every few turns of the bolts so as to be sure everything is still free. When the clutch is tightened all the way, pull the tool out and the transmission input shaft and spline shafts should now fit into the clutch assembly. You have to rotate the PTO shaft while putting the tractor back together and you may have to even rotate the flywheel a hair to get both spline shafts to ease into the clutch discs, but it will go eventually. Without the pilot tool you have less of a chance of a smooth re-assembly. As I noted before, if I can do it, you can do it. I'm no mechanic nor a rocket scientist, believe me - just a country blacksmith with enough tools to get himself in trouble. :-) Rich
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roy697
CTW Advanced Member
Roy's Pond
Posts: 303
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Post by roy697 on May 23, 2010 23:19:55 GMT -5
How about a few pictures of your tools?
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Post by Rich Waugh on May 23, 2010 23:44:50 GMT -5
Geez, my tools for working on tractors and such are pretty boring - wrenches, hammers and welders, basically. Everybody already knows what those look like. Here's some pictures of my blacksmithing tools: This is the forging area in my shop, with a couple of my anvils and my homemade pneumatic power hammer. It has a 65# hammer head and hits at about 240 blows per minute. Some of the other stuff like my homemade 2x72 belt grinder, mill drill, swivel-head horizontal band saw, fly press, jeweler's bench, etc. That's the back shop. The front shop has the table saw, scroll saw, chop saws, hand tools, sheet metal break, and what passes for an office area. It's a work in progress, as we say. So there's some tools. I can always use more, too. Just ask my wife. :-) Rich
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Post by affordable on May 24, 2010 5:29:58 GMT -5
Rich, just a note, the main clutch disc is inside the assembly,the PTO disc is the loose one all the way in the front. Tommy Affordable Tractor Sales "Your Jinma Parts Superstore" www.affordabletractorsalesco.com
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Post by shotley on May 24, 2010 10:48:49 GMT -5
I like your idea of the plywood disc to drive the seal on. That is something I can handle. I don't have a machine shop but can cut wood. I did not understand that the main clutch disc would be loose so will work on that one. Your description gives me a big head start on the job. Thanks millions for the pictures.
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