case 580b overhaul and transmission

[Papa Goose]

OK, here's the latest. I found the reason for the leak this morning - the four side bolts holding the tranny to the torque tube are all loose. Looks like the top and bottom bolts are still pretty tight, and the joint hadn't opened up, so I don't think there's any damage from misalignment. This certainly explains why the fluid was pouring out. I also pulled the shuttle and shift covers off, and everything looks perfect - no evidence of any problems at all. It's tempting to just tighten everything back up and run it, but I've got it down this far, so I'm at least going to pull the shuttle and replace all the gaskets and seals.

Fact is, I've never actually seen this tractor move, because I bought it after the leak got so bad that the previous owner couldn't keep fluid in it long enough to use (hey, the price was right), but he said it drove fine before it started leaking, and so far, everything else he told me has turned out to be true, so I'm not really expecting to find any major problems.

The shuttle valve body looks perfect - no leaks or looseness anywhere, so I'm really tempted to just leave it alone. I would like to take a look at the pickup screen - maybe I can snake my borescope in there once I get the shuttle out. If the screen isn't clogged up, I think I'll just leave the front cover on. Even though I've got the back end all apart, it really doesn't seem like that's improved the access to the front shuttle cover - looks like it would be easier to take that out by pulling the tank, which I could do after I get the rear end put back together. That way, I can test everything, check pressures, etc., before tearing anything else apart - who knows, maybe it will drive just fine once the leak is fixed.

Does this make sense, or should I just tear it all apart while I'm at it? PG

 

[Phil]

If you don't pull the big cover off, you won't be able to clean the screen on the pump pick-up tube effectively, however, it may not need it. Also the 2 seals between the pump and the cover can't be replaced, however, they may not need it. The pump may be damaged from lack of oil, but it may be okay. A lot depends on how long the machine was run with no shuttle oil pressure.

I tend to agree with your plan, inspect and do some preventative maintenance on the shuttle assembly for now. After all, we don't know if the clutch discs or bearings have been damaged from low oil pressure/low oil.

I have added a pic with the shuttle assembly out, looking forward, you will see a pile of debris that was found resting just under the screen, and plugging it. In this case the machine was working good until it was driven on to a steep float deck. Hence the need to reach way up in the torque tube and wipe the bottom clean. So you should be able to see the screen from the rear, as I recall. Remember to note the orientation of the bottom gear when you remove it, before sliding the shuttle out.

Keep track of your shims on the main shaft as you split the tractor, also one bolt on the rear shuttle cover has a different size head. You will have to remove the small cover to get the 2 top housing bolts. Phil

 

[Papa Goose]

Well, this project is just full of surprises. I've been thinking all along I could just take out the 8 bolts holding the loader/hoe lower frame to the rear axle, remove the fender/cab attachment bolts, and roll the rear axle backward. Had everything ready to do that and then realized that the lower frame is only bolted on one side - the other side is all welded into one big frame that goes from one end of the tractor to the other, so that isn't going to work (I must have skipped class that day).

Anyway, here's the new plan: disconnect the loader arms and cylinders, blocking them up in place. Remove the hydraulic lines running from the loader frame to the cooler, filter, etc. as required. Remove the hood and cowling over the instrument panel. Block up under the engine. Block up under the loader frame, but with rollers so it can move fore and aft. Remove the bolts holding the loader frame to the radiator frame. Now I should be able to move the loader frame and rear axle together back enough to split between the torque tube and the tranny. Not sure how far it has to go to release the splines on the driveshaft, so I'll probably end up taking off more bits and pieces. Good opportunity to drain all the old oil out of the hydraulic system (I'm trying to be positive).

Clearly, it makes sense to drop the torque tube while I'm in this deep (I'm sure Phil would agree), so I figure I'll use my engine hoist to maneuver it back until it releases and then drop it down to clear the steering column. Once that's out I can do all the things Phil has suggested - hopefully that means just seals and gaskets, but I know it has been run without oil, so there may be more damage. I'll post the results.

One question Phil - I didn't catch what do you meant by "note the orientation of the bottom gear when you remove it, before sliding the shuttle out" - is there a special way that goes in?

Thanks again for all your great advice!! PG

 

[willie59]

One question Phil - I didn't catch what do you meant by "note the orientation of the bottom gear when you remove it, before sliding the shuttle out" - is there a special way that goes in?

I caught that myself PG. Phil will be back tomorrow and enlighten us. It amazes me how good he is with the B Case. It seems you've had to regroup and go back to Phil's approach of disassembly. He is the B Master on HEF. :notworthy

 

[Phil]

Papa,
The gear in question is the lower rear counter-shaft gear which has to be installed with the large hub in. Just make a note of examining it when you remove it, just prior to sliding the shuttle assembly out of the torque tube.

I don't know how your removal technique will work out Papa. I've never done it that way, not with an engine hoist. The main concern is alignment when reassembling the 2 halves, they are not very forgiving. One of the first difficult tasks is removal of the hydraulic pump inlet hose assembly and the 2 inlet pipes in the loader frames. Sometimes it's better to cut these hoses and install new. Phil

 

[Papa Goose]

Was finally able to split the tractor between the torque tube and the tranny this morning. The hard part was getting the supports adjusted so that the torque tube and tranny didn't load each other - there's no easy way to tell other than to see how hard the two are to separate. I ditched the idea of the engine hoist and just put a rolling floor jack under the torque tube - that worked pretty well. Once I got everything aligned, the two halves slid apart pretty easily. I'm hoping this will be much easier during reassembly, since I'll be able to line them up more exactly before they mate.

I ended up taking out the steering column and the tank, which will just barely fit down and under the loader frame with the steering column out. Then I was able to remove the valve body and front cover. The good news is that the pump is perfect - you can still see the tool marks on the housing, so I don't think the engine ran long enough to do any damage, or maybe there was still a little oil in the lines? The pickup tube has a good bit of crud on it, but not totally clogged. Now everything can get a good cleaning!

I'm debating going any deeper - so far everything I've found looks pretty good, but this seems like a strategic time to change the rear main engine seal and the tranny input seals?? On the other hand, I wasn't planning on doing a restoration - I just want this thing to run well enough to dig out some tree stumps and level off my airstrip! So, maybe I'll stop here. I'm going to put in all new gaskets and seals, including a shuttle kit - seems like that should make a pretty significant improvement.

 

[Phil]

Papa,
Do check the 3 sealing rings that seal the shuttle shaft to the torque tube housing. Sometimes the housing is worn where they ride. You will encounter them in the shuttle assembly itself also. They need to be 'hooked' together, placed in the bore, noting the gap in the 'hook'. Like an engine piston ring, they must exert pressure to seal, in this case.

Like the engine rear main seal, the 2 transmission input seals, generally do not cause problems. However, the top transmission shaft sometimes has considerable end play as the tapered bearings wear, and I have adjusted this in the past. Input shaft seals can be replaced at this time. Phil

 

[Papa Goose]

Phil, I'm looking at the A41000 kit, which I think has those sealing rings. If not, I was going to buy new ones, but I'll check the gap - any idea what it should be?

I disassembled the shuttle yesterday - everything looks good - lots of material left on the clutch disks, no sign of burning or discoloration, bearings are all in excellent shape. The rubber seals are actually not horrible, although they're swelled and worn - not that I would ever consider reusing them, but I was pleased to find the shuttle pretty much in working condition. As I mentioned earlier, I've never seen this machine move under its own power, so I wasn't sure what I'd find - like, the torque tube full of scrap metal?!! PG

 

[Papa Goose]

Here's the latest twist - I was getting ready to clean the old gasket off the torque tube/tranny interface and suddenly noticed that there wasn't an old gasket there!! Closer inspection revealed a few tiny torn up pieces stuck in the various holes and spaces on the two mating surfaces, and it looks like at least some of the crud in the bottom of the torque tube is actually ground up pieces of gasket.

Has anyone ever seen a gasket self destruct this way? I never have. Honestly, there isn't a shred of it anywhere on the mating surfaces - only tiny bits in the holes and spaces. This certainly explains the leak!! But, the "chicken and egg" question is, did the gasket disintegrate because the bolts loosened up, or did the bolts loosen because the gasket went away???

I suppose it doesn't really matter - I can't see any damage to the mating surfaces, and the bolts were tight enough that the two cases never shifted enough to damage the shuttle, splines, bearings, etc., so I think I can just put on a new gasket and go. But, you can bet I'm going to be checking the tightness of the bolts on a regular basis! Also, I'm going to need to check the end play on the shaft - I guess there's no easy way to do that without putting it together, then will have to take it apart again if a change is required - seems like there ought to be an easier way.

Don

 

[Phil]

Papa,
I'm sorry I didn't mention to check shuttle shaft end play when you where taking it apart. You are really on the ball. Yes you will have to check this dimension on assembly.

I just replaced a leaking torque tube/trans housing gasket on a 430 backhoe. The bolts were all loose, I don't know why the owner didn't check this but anyway the bottom half of the gasket was missing, just the odd bit here and there. A new gasket is not available, so I asked for a 580B gasket but they said it they thought it was different. Anyway, I used the Loctite 515 sealer they recommend. I believe there are 2 dowels and I think one is hollow(it can slide off the stud), so check that they are there.

Re the steel sealing rings, look at the gap where they are hooked together, when installed. If when installed in the exact spot it normally runs in, the gap is closed, then the ring cannot exert any pressure to seal, because the hooks will not allow it to open any further. The percentage of gap left determines it's service life. Check all of these rings for side wear also, and remove every one of them carefully and check them in their respective bores. If you reuse them put them back the way they come out. Aluminum bores can be carefully polished with fine sandpaper, I use garnet paper not emery, and this does a good job to smooth the dirt scratches.

I have a few notes on the Rockwell, I will get back to you with them.Phil

 

[Tinkerer]

blee62, Did you get your transmission fixed so that it will stay in gear ? I finally repaired the transmission in my 680. It turns out it wasn't so much the worn gears that was causing mine to jump out of gear. It was caused by a broken snap ring on the main driveshaft. That allowed the gears to be out of alignment when it was in gear, especially under a load.The transmission had been worked on before by someone who didn't know much about what they were doing. I found that out when I found a second snap ring on the input shaft that had been expanded farther than it should have been. The result was a permanently oval shaped snap ring that was almost certain to fail also. I always replace snap rings that show even the slightest distortion after being removed.They also stripped the threads in one of the four bolt holes that hold the transmission against the shuttle adapter plate. Tomorrow I am going to try a slightly larger in diameter metric bolt in the stripped threads. If that doesn't work then I will remove the transmission again and drill and tap the adapter plate for a 5/8 inch bolt. Case used 9/16 inch bolts to hold it against the adapter plate.

 

[Papa Goose]

Phil,

I slid a hook ring seal into the torque tube bore, and there's a gap about the thickness of my fingernail. I can try to get a more accurate measurement if you think it's necessary, but I plan to put new seals in anyway - they're only $30.

I'd be very happy to see your notes on the Rockwell (Rockford?) - I'm going to get started as soon as the dealer can get me an A41000 kit - hopefully just a day or two.

I also noticed that two of the shims on the input shaft look are cupped slightly. I'm assuming that when the case bolts got loose the spacing opened up and allowed the shuttle to hammer a little on the shims - does that sound reasonable? Should I replace the shims? Had another idea - I'm going to try to estimate the gap by measuring both sides with the cases apart, maybe with a dial indicator or digital caliper. I'll also have to estimate the thickness of the compressed gasket, but I figure I can get within the 0.045" tolerance. Even if I don't, it just means I have to split the cases again, which I would have had to do anyway. I'll let you know how that works out.

One other question - I'm looking at the input shaft to the gearbox and wondering if I really want to replace the seals. On the one hand, it will never be easier than now. On the other hand, they aren't leaking and they have a pretty easy life - oil on both sides and no pressure, so they should last forever. They're about $35 to replace with the gasket. Any thoughts?

PG

 

[Phil]

Papa,
Yes as long as there is some gap left, the ring will apply pressure. Just a common sense thing. I have seen torque tube bores with grooves worn in them from these 3 rings.

I have seen the shims you refer to, cupped as you describe. I agree with your logic as to the cause. As long as they are still working as designed...should not need replacing. You seem pretty sharp mechanically, I'm having a good feeling about your project.

I have not seen an issue with the transfer of oil from one compartment to the other in the 580CK or the 580BCK.

Some notes on the Rockwell soon, been busy and trying to get caught upPhil

 

[Papa Goose]

Finished rebuilding the shuttle yesterday and popped it back in. Gaskets arrived today, so I bolted everything up and checked the gap - it was about .040" before torquing the bolts, so I figured that was close enough. Coated the gasket with RTV and torqued everything down. Nice to have the thing off the blocks - I'm used to working on sports cars, where nothing is particularly heavy, so this hunk of iron makes me nervous - way too much gravity here.

Now I'm really anxious to see how this tractor moves, so I'm going to try to get the pump and valve done by this weekend. The oil that came out wasn't too bad, just a bit murky, but I'm still going to try to get as much out as possible - figured I'd suck on the cooler lines with my shop vac - how easily does this stuff burn? Maybe I should find out before trying this (I've heard of people blowing up shop vacs trying to suck up gasoline).

I've also been trying to come up with a better solution for the hydraulic system than flushing with new $$$ oil. I drained as much as possible from the reservoir in the loader frame (about 10 gallons), which looks very much like chocolate milk, but I'm guessing there's still a few gallons left in the hoses and cylinders - seems like a huge job to disconnect all that stuff so it can be drained, not to mention all the small leaks that would inevitably result. So, I've been doing experiments on the old oil - I've found that if you heat it to just below boiling for an hour or two, it gets a lot darker and clearer. I realize that sounds like a contradiction in terms, but when the water evaporates the "milkiness" goes away and it looks a lot like motor oil.

So, my plan is to run this "dewatered" oil through a filter and then put it back in and run the machine long enough to mix it with whatever is left. Drain, dewater/filter, and pour it back in, then repeat until what comes out looks like what went in. At that point, I should have most of the water out of the system and I will do a more complete drain and refill with fresh new oil.

Any thoughts?

 

[Phil]

Papa,
You really get work done fast. Regarding the shuttle oil change, when the front torque tube drain plug is removed, it wouldn't hurt to check the torque converter for a drain plug. I don't think there is one on a B model but just in case. There is actually a drain on the filter housing too.

Re the hydraulic system milky oil, there were some recent posts on the problem. ATCOEQUIP can advise you on that too. I'm afraid my attempts to fix that problem have not been very successful. My first thought on heating oil to remove moisture is that there is a temperature you don't want to exceed. Do make sure both tank vents, on the left and right side hydraulic tanks, are clear and not letting rain water in. Phil

 

[Tinkerer]

Papa Goose;
Read seagull369's thread (Question About Fluids). The thread was started on 9-24-2009. All the info and advice you need is there pertaining to your contaminated oil.

 

[Papa Goose]

Thanks Tinkerer - I'll check that out.

Phil, I'm really motivated to see this thing go, but time is really tight right now - hopefully I can get it going next week during Fall Break. PG

 

[Phil]

Papa,
I'm swamped here, I have so many things to do in the next few weeks. When filling the hydraulic tanks on a B there is a vent plug on the left frame at the front. You will have to let the trapped air out there when filling. Good luck, Phil

 

[Papa Goose]

Tinkerer,

OK, you've convinced me - your flushing method sounds like the right way to get rid of the contaminated oil. I was hesitant about disconnecting everything (afraid I'm going to get a lot of small leaks), but I can't think of any better way to get all the gunk out of the cylinders.

I was thinking I might try to reduce the amount of new oil required for flushing by disconnecting the line out of the pump and hooking it up to my air compressor. That way, I can open one line at a time and blow out the crud without using new oil. I was also thinking that if I disconnected one of the pins, it might be possible to cycle a cylinder with compressed air - that would be a nice way to clean them out. Any idea how much pressure it would take to move an unloaded piston?

After clearing everything possible with air, I plan to reconnect the pump, put in fresh oil, and then flush again (which shouldn't take a whole lot of oil). Seems like that ought to do the trick.

How did you clean out your reservoir tanks?

PG

 

[Tinkerer]

Papa Goose; You can try using air but I don't think it will flush out all the contaminated oil. Plus you then have a system full of air with a certain amount of frothy oil. That seems to me to be a real harmfull condition to subject your hydraulic pump to. You won't lose very much new oil if you take your time and watch the disconnected hoses for the first clean oil to come out. I did remove the dipper arm pin so that I could extend it with new oil,without disturbing the boom cylinder. My Case 680 Has an oil tank right in front of the windshield. It has a round access plate about 8 inches in diameter that I can remove. The purpose of it to get access to the hydraulic filter that is in it. With the filter out it is very easy to clean the tank. And believe me the tank had more than contaminated oil in it!