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Post by Rich Waugh on May 14, 2010 3:38:17 GMT -5
I'm going to have to get a touch creative on the dolly issue because the only floor jacks I own are the little low-buck ones suitable for a car or light truck. Not enough reach or beef for a tractor, I don't think.
I have a floor dolly I use for moving big hunks of steel in the shop. It has heavy-duty hard wheel casters and a 3x3x3/8 angle iron frame with 1-1/2" plywood deck. I figured I could take my 10 ton bottle jack and secure it to the deck of the dolly and weld up a saddle for the top of it to fit the transmission. Since the bottle jack has a screw post extension I can weld a handle on that and use it for finesse height adjustments.
Thanks for the reminder about blocking up the front axles. that is on my list. I still need to get some clean buckets for all the fluids.
The replacement gaskets arrived today (in fine shape this time due to much wetter packing) so I'm hoping to get the tractor in place Saturday and drained, unhooked and blocked up. Sunday I'm going to get a buddy of mine to come help me split it and re-assemble it - I hope. I'll turn a pilot tool on the fly. When that is done I'll get busy on the loader braces and a couple other little chores.
Rich
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roy697
CTW Advanced Member
Roy's Pond
Posts: 303
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Post by roy697 on May 14, 2010 9:03:54 GMT -5
That is good news that you have a plan. Take a minute & think before you get into a position that can get you hurt, that thing weighs enough that if it falls on you...... I went to a funeral last week, a friend was working on his dump truck, got careless just for a minute & was crushed between the frame & dump bed. Just be careful.
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3RRL
Administrator
Huge Kama
Posts: 2,027
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Post by 3RRL on May 14, 2010 13:04:22 GMT -5
Yeah, like Roy says, be very careful. I always use 4x4 or 8x8 wood blocks to support the tractor instead of relying on the jacks. I have metal jack stands but prefer the HD wood blocks.
This is probably way too early, but when you get ready to slide the tractor back together again, note that the splines on the PTO clutch disc are the first to touch. Next are the splines on the main clutch disc and finally, the shaft which goes into the pilot bearing. So you will need to rotate the crank or flywheel a little for the splines to engage, while sliding it together. At least that's the way my Kama went together.
I found it odd that the pilot bearing shaft was the last to make contact. I figured that shaft should be the first to help line up the clutch disk splines and 2 halves? Don't know if the Jinmas are the same way or not? Maybe one the dealers can tell you that?
One thing Tommy told me was NOT to use the bolts to suck the 2 halves together until you are SURE that BOTH clutch disc splines and pilot bearing shaft are ALL lined up. What I did was measure both halves with a depth mic in relation to the bell housing flange. But you could use a machinist's steel rule to get approximate dimensions too. I used those measurements to calculate when each component would start to engage, relative to the gap (opening) of the bell housing. So when the bell housing flange was open a certain distance, I would know, "Oh, the PTO clutch splines are now engaged". And as it got closer together, "OK, the main clutch splines are now engaged", and finally the pilot bearing shaft. Once I was certain that all were successfully engaged, only then did I use the bolts to suck up the rest of the gap. Rob-
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Post by Rich Waugh on May 14, 2010 16:39:33 GMT -5
Today I did some weed whacking and blowing of debris in the area where I park the tractor, getting it ready to do the work on it. I opted not to use the concrete slab area I had been considering since it is a couple of inches out of level in the direction that would be side to side in use. It's also three feet higher than my parking area and I'd have to jumping up and down all the time going to get tools form the shop. The ground where I park the tractor is level, densely-packed gravel mix about like road ballast. I beat it down with a plate compactor when I put it in so it doesn't shift around. I'll drop a sheet of 1/2" OSB on it and put the lowboy dolly on that. Should be just fine.
Tomorrow I'll move my cherry-picker hoist out there and start the dis-assembly work. The first order of business will be to make up the lowboy dolly with the jack and cradle for the rear half and chock and block the front half. Then I'll drain the appropriate fluids, pull off the rear wiring, remove the starter, unbolt the floorboards, clutch safety switch, etc. The steering motor and support will need to be unbolted form the bell housing and then I can lift the whole assembly, cowling and all, a few inches with the cherry picker. That should allow the bell housing to clear when I roll the back half away, according to Tommy.
Once all that prep work is done I need to make a run to the hardware store/auto supply and pick up new grade 8.8 or better bolts and washers for the bell housing and transmission joints. Then get a good night's sleep so I can finish the job on Sunday.
So, I have a plan. We'll see if it comes together... :-)
Rich
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Post by stumppuller on May 14, 2010 22:09:48 GMT -5
Man, when I read about all of these steps to go through, I get a sick feeling. I am not looking forward to this job.
Rob, you've split your tractor twice aleady!!!! You da man!!
Bruce
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Post by bradblazer on May 15, 2010 8:51:23 GMT -5
Good luck today Rich!
Sounds like you have a good plan. It can be a challenge finding the right bolts - I hope your local store has a good selection.
Adding the rear axle brace is a good move in my opinion. I know the geometry is strange so it's hard to see exactly how it provides benefit. Let me add my version to Rob's excellent explanation.
All of the load and torque to support the loader is transferred to the horizontal tubes bolted to the bell housing. With no bracing there is no way those bolted connections would survive the torque that is large enough to lift the rear of the tractor. All loaders have braces from the tubes to the front of the tractor frame to help counteract that torque. To transmit that torque to the earth, the weight plus moment pushes down on the front axle with the rear of the tractor acting as a counterweight. Imagine the rear wheels off the ground due to an overloaded bucket. Everything behind the bell housing is now hanging from the bolted connection you are about to fix.
Now imagine you have a pinned link from that unused lower bracket to the rear axle. If the back of the tractor tries to droop, the link will act as a strut in compression and help to support the weight. If the link is solidly bolted or welded and it has some bending stiffness it can contribute even more to the overall strength and stiffness of the structure.
Obviously the structure can handle the stress as is since it didn't immediately fail but repetitive stress/fatigue is what you want to protect against. If your connections aren't perfect and you introduce some residual stress upon assembly it will probably be more than offset by the reduction in cyclic stress. Properly torquing the bolted connections also goes a long way to reducing cyclic failure. Friction between the plates due to the clamping force of the bolts should be what supports the load. In tension, the stress within the plates changes but a properly torqued bolt does not see any cyclic stress.
The reason you can measure a gap at the bottom of the flange and not at the top is probably due to the current load condition. If you were to jack up the tractor at the center the bottom gap should close and a gap should open up at the top. That little bit of slop can get worse fast since it introduces shock loading to the cyclic stress.
I rambled. Hope it makes some sense.
Brad
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Post by Rich Waugh on May 16, 2010 21:26:23 GMT -5
Well, I started the procedure today - doctors call it a "procedure" when they yank your stomach out through your rectum, so this is a "procedure" too.
Didn't take me long to discover that the notion that I got from Tommy of raising the cowling/steering motor/fuel tank arrangement to clear the bell housing just wasn't going to work. The bracket for the fuel tank on my tractor is bolted to the top of the bell housing and those bolts are not accessible with the fuel tank in place. Okay, change of plans.
I went ahead and disconnected all the wiring form the engine and tucked the harnesses up inside the cowling. Disconnected the fuel cutoff, decompression lever, fuel line, and the hydraulic hard lines for the power steering and hydraulic pump. Managed to do it without to much mung and drool all over the place. That was good.
Took a couple of hours to make up a lifting saddle for the transmission and a carrier for the hydraulic jack I'll be using to lift the rear of the tractor.
Got the front end shimmed so it shouldn't tip sideways, blocked up under the oil sump and disconnected the rear of the front drive shaft - didn't even lose the ball bearings. I've been putting each set of fasteners I remove into a labeled zip-loc bag for easy reference later. Hopefully easy reference, anyway.
With all that done I decided to put a bit of pressure on the jack and start loosening the bell housing bolts. Okay, that went off alright, but I can see I need to work a bit more on getting the two halves in a perfect line before I try to split them. The bell housing is showing a bigger gap at the bottom than at the top. Deal with that tomorrow.
Tomorrow I'll finesse the blocking and jacking to get the gap looking all parallel and then I'll try to roll the back half away and see what happens, I guess.
I did discover, while rummaging around in the toolbox of spare parts that came with the tractor, and brand new seal that appears to be a rear main bearing seal, though it looks different from the one I got from Tommy. The one from Affordable is a metal shell with one rubber lip and one plastic lip and the Jinma one is the standard old two lip with a spring type that I'm used to. I'm curious as to why the two are different - tomorrow I'll have to call Tommy, I suppose. Sure be handy if I wasn't so damn ignorant of all this stuff!
There it is for now...
Rich
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Post by stumppuller on May 16, 2010 22:59:40 GMT -5
I'm following your "adventure" with great anticipation, hoping to learn what to avoid & what tricks to apply to my situation.
Bruce
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Post by Rich Waugh on May 17, 2010 23:15:28 GMT -5
Well, I did it. Today I split the tractor in half. Had me puckered up tight enough I'd need a D-9 Cat to pull a straw outta my butt, but I got it apart and didn't even drop it on the ground. I spent a lot of time on the jacking and blocking to make sure the two halves were absolutely lined up with each other. Once I though I had it right, I loosened the bell housing bolts and backed the rear half off about a quarter inch and checked the seam between the bell housing and flywheel housing. The gap was a bit wider at the bottom so I added a bit of blocking to the front half until I had a parallel seam and then rolled the back half away. Slick as poo. I don't have a big floor jack so I used a lowboy dolly and a bottle jack with a corral I built to hold the jack in position and a saddle I made for it to rest under the transmission just aft of the transfer case. Then I laid down a couple of boards screwed to the sheet of OSB I'm using for a floor; the boards make sure the dolly runs back and forth in pretty much a straight line so I don't lose too much alignment - I hope. One thing I discovered when unbolting the bellhousing was that the bolts were hardly tight at all. The only one that was at all tight was the one that is hidden inside the clutch access window. The rest were easily removed with one hand on a fairly short box end wrench - didn't have to even pull hard. The gasket was also obviously put in out of position, too. That joint being able to chatter probably didn't help the flywheel housing to block joint at all, either. Find out more about that tomorrow I suppose. I pulled the clutch and then ran out of daylight. Clutch disc doesn't look too bad, but the main flywheel looks a bit gnawed on. May just be debris, I'll know more later when I pull it and give it a lick with some sandpaper. Rich
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Post by Rich Waugh on May 20, 2010 2:06:27 GMT -5
Update: Pics will have to follow later as I'm too tired to mess with 'em right now. Last night I pulled the flywheel cover and in doing so found that the bottom three bolts were loose enough to be removed with my fingers. The rest were just tight enough to need a wrench. The gasket was chewed to shit at the bottom and there was nothing left of it for the three inches across the middle. No surprise it leaked some. :-) I cleaned everything up this morning and checked out the bolts. No need to replace them at all. They're black oxide bolts with shouldered heads and they're in pristine condition. They appear to have rolled threads as opposed to turned ones, too. Good quality, in short. Better than I could obtain locally, too. No evidence of anaerobic thread locker having been used, either. I depth gauged the holes and then then checked them with the bolts and the bolts and holes are a perfect match. Maybe one and a half unused threads is all. I couldn't do any better if I tried so I'm not going to. The flywheel that I thought might have looked a bit gnarly seemed reasonably fine - just had so little polishing from use that the clutch dust on it made a "pitted" looking pattern. Cleaned it up and the turning marks are still evident. It isn't as shiny and perfect as I'm used to from cars I've worked on, but then it isn't a car, either. I'll leave it alone unless someone gives me a good reason to do something to it. I have no way to face it myself so I'd have to job that out to the local machine shop which hasn't inspired much confidence the one time I used them in the past. The friction surface being down in a hole like that makes it tough for me to even sandpaper it very well. How smooth should it be, ideally? I cleaned everything up, installed the new gasket and re-installed the flywheel cover using blue Loctite on the threads. The books didn't show any torque spec for the bolts so I used a general purpose torque for that size (12mm) metric fastener of grade 8.8 to 10.9. The dry fit torque for 8.8 is 59 ft/lb and 10.9 is 83 ft/lb so I went with 75 ft/lb since I figured that the Loctite is a slight lubricant during assembly. Should hold, I think. I also used the Loctite on the flywheel and torqued it to spec as per the engine manual. I opted to use the blue Loctite rather than the red since I'd really hate to have to pull those bolts later and have them tear out the cast iron threads. I really think things were just not properly assembled at the factory and this will cure the problem for good. Still, why create a problem if I don't need to? I turned myself a clutch pilot tool from a piece of scrap steel and used that to align the clutch and installed the clutch pack on the flywheel. Again, no book specs for the bolt torque so I used 45 ft/lb for the grade 8.8 bolts. Loctite, of course. The blue, thankfully, since installing the clutch assembly may turn out to have been premature. Tomorrow I'm going to pull the clutch pack back off, it looks like. I just now looked up Larry's clutch adjustment thread and now I'm a little nervous about my clutch disc. I eyeballed it and thought it looked okay and the bellhousing wasn't knee deep in clutch dust so I figured it was probably okay, but I don't remember it having as much meat as the picture of Larry's new one. I've had no internet at the shop the past few days so I couldn't check it before I put the damn thing on, and now I'm second-guessing that decision. If it isn't at least 95% of new I'm going to order a new one. After all the tractor only has a bit over a hundred hours on it. That damned flywheel housing being so loose and the bellhousing not being plumb tight may have had the clutch chattering whether or not I could actually feel it. Rather not replace it in six months! Oh well, at least I didn't use red Loctite on it. :-) I have to go away for three weeks starting on the 25th and I really wanted to have this thing finished before I went - hate to leave it sitting open all that time. But if I need a new clutch disc or the flywheel faced that ain't gonna happen soon enough to meet that deadline. Too much happening all at once. So far though, I guess it's going reasonably okay. I haven't gotten hurt or destroyed anything yet, at least. I hope it keeps going okay. This stuff is all a bit over my pay grade, but I'm taking it careful and muddling along. I'm also pestering Tommy and Ronald on the phone every now and then. Thanks guys! Rich
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Post by affordable on May 20, 2010 4:27:23 GMT -5
Hey Rich,sounds like you are making some good progress ,taking your time.I would assume if your clutch was adjusted from the start your going to be OK on the main disc wear at a 100 hours,we can measure a new disc for you to compare it too if you want.Keep us posted on your progress,hopefully it will be back together soon. Tommy Affordable Tractor Sales "Your Jinma Parts Superstore" www.affordabletractorsalesco.com
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Post by Rich Waugh on May 20, 2010 9:16:36 GMT -5
Thanks for the kind words and all the help so far, Tommy! You and Ronald have both been real wonderful about answering my questions and providing good advice. Real gentlemen, both of you. This morning I measured the clutch disc and it appears to be 10.3(+) mm thick as near as I can tell. Larry's picture of his new one showed 10.9mm so mine is just about 94% of new. I can live with that, I think. I'll possibly get a couple tenths of fairly quick wear as it settles in again in the new configuration and then it should be pretty much down to normal wear from then on out. Should be okay, right? When I was out there fiddling with that, a pair of these beauties landed in a nearby tree and shrieked at me a few times just to say, "Good Morning!" Then they flew off, presumably to go chow down on the many ripe mangoes around the place right now. They've been hanging around here for a week or more now - no idea where they came from, the nearest place they're indigenous is Venezuela as far as I know. Pretty SOBs, and big too (30" nose to tail), but really noisy. Life in Paradise, huh? Rich
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Post by affordable on May 20, 2010 9:34:51 GMT -5
I think that's fine, maybe you can get this thing together before you have to leave. Tommy Affordable Tractor Sales "Your Jinma Parts Superstore" www.affordabletractorsalesco.com
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3RRL
Administrator
Huge Kama
Posts: 2,027
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Post by 3RRL on May 20, 2010 9:48:46 GMT -5
Hey Rich, Great progress and thanks for taking the time to document it all. What a bummer about those bolts being so loose. That just goes to show you how important it is to go over the tractor's bolts to be certain they are all to torque specs. Of course how are you gonna check the flywheel bolts without spitting it. That sure is one area the Chinese can improve on...their quality control...a subject discussed over and over again. I'm wishing you all the best in getting it back together, and good luck on your upcoming trip. Rob-
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Post by bradblazer on May 20, 2010 22:19:43 GMT -5
Rich, Sounds like you're making good progress and having good luck so far. The macaws are cool.
Quality control - so much of the machine is very nicely made. The critical stuff they get wrong really makes you wonder.
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