DK45 HST blues

[Harry in Ky]

Another day, another kick in the head. So the little beast was assembled far enough to start it up today. Results were a mixed bag. Some good news, some not so good.

The Good, the Bad, and the Ugly.

First the Good. The hydrostat functions as advertised. A minor (I believe this to be the case) adjustment on the pedal control linkage should solve the bit of forward creep it has. When I first started it up this afternoon it would grind gears just a bit when shifting the range into gear. It bumped a few times, slipped into gear and started creeping forward. I could stop it with the brake, then I shut it off. I hadn't bolted the pedals on yet, torn between putting the floor mat back first or just the pedals first and removing them again for the floor mat.

The Bad. When I looked underneath for the pedal adjustment I see oil draining from the clutch housing making a small puddle on the floor below. Maybe 1/2 cup or so. Major disappointment. I don't think it's the unit leaking, but more the input shaft/PTO drive gear/ front seal area. I've been studying diagram again trying to decide what might be leaking in there other than the seal. Not much else comes to mind. It didn't seem to leak while running, rather it starts as soon as the engine shuts off. I tried it again after bolting the pedals on and if I hold the reverse pedal down just a touch it will find neutral, shift in and out of gear with no problem or creep. Both forward and reverse directions seem to work, I just need to adjust that neutral spot a bit. If that were the only issue I would be a happy camper.

The Ugly. We obviously can't live with the internal oil leak, so it's got to come apart again. I expect as usual, it will come apart much quicker the second time around.

 

[Robin Veerman]

Sorry to hear about the leak…but you found it before you buttoned it all up. Hopefully it’s an easy fix

 

[Harry in Ky]

Sorry to hear about the leak…but you found it before you buttoned it all up. Hopefully it’s an easy fix

Before it's buttoned up? Not exactly. The only things left on the floor were the floor mat and the two side braces for the loader mounts to the rear axle housings.

Another update (for anyone who still cares). I took a break from it for a few days to let my attitude clear. I find that with projects like this if I jump back in the next day while I'm still mad at it, things don't usually go well.

I got a late start on it today, but five hours later the clutch housing with the unit still bolted inside is hanging on a hoist. It's up at shoulder height where I can peer inside from all directions, angles, up, down, and sideways to see if I can determine where it's wet, where it's dry, and so forth. I was glad on one note, the very front of the unit was dry. The propeller shaft (gotta love that term) is still in there dead center under the unit, I can clearly see the front two thirds of the shaft and the lower portion of the unit case are dry as toast. I say I was glad of that fact for this reason. I had an "oh ****" moment earlier when preparing to remove the steering column assembly and noticed that there are the two holes in the top of the clutch housing where the first overflow tube comes out, and goes back down into the second overflow tube. I knew the holes and tubes were there, but hadn't remembered that the steering valve was above and just slightly forward of that spot. Removing the hoses from the valve dribbled some oil onto that tube area. I'm pretty sure that area was dry when I began removing plastic from around the column, but I couldn't help puckering at the thought. What if I didn't get all four lines tight, one of them leaked, oil ran into the holes and came out the bottom? Could THAT be all it was? I thought better and moved on. Later on the hoist I see that wasn't the case.

Okay, so I move on. I'm looking for evidence at any (or all) of the gaskets I can't replace for signs of fresh oil that don't appear to be anything I spilled in the process. The two smaller ones, one on top of the bore containing the servo piston appears to be dry. The one on the side plate containing the control shaft appears dry. That leaves the big one at the very back of the unit where the body containing the relief valves, wear plates, and all that stuff meets the main case, I cant see under it yet, as that is where the unit mates up to the clutch housing. I can stick a mirror into a couple places and try to get a view of the joint but not really very much. As I'm doing this I notice a drop of oil on the mirror glass. It was dry when it went in, but as I move it around more and more drops seem to be showing up on the glass.

It still doesn't add up. When I removed the overflow tube up at the top front, I could see the oil down in the hole the tube came from so the case is still full. The area between the two housings is dry, so none of the new seals are leaking, it must be something on the unit itself. Well, tomorrow the unit comes back out of the clutch housing and hopefully something will show up that makes sense.

One thing is certain. When it goes together the next time, a little creative plumbing and wiring will take place. It will start, run, and (hopefully) move, but the floor plate, steering column, and all that other stuff will still be in a pile on the floor.

 

[K5lwq]

Harry I do not envy you one bit on this project! What a pain in the backside! I hope you find an obvious leak and can get it stopped without too much hassle.

 

[Harry in Ky]

Well today's installment is no better than the last. I went back and studied the situation again, and determined which of the possible problem areas are NOT involved. What i saw running out on the floor came from an opening in the clutch housing, just slightly forward of the clutch housing/rear case joint. Directly above that opening is the rear portion of the unit. The gasket I was most afraid of is directly above the joint where the two housings meet. There is another drain hole in the rear main case just inches away from that joint. No doubt that a leak at this gasket and oil would be on both sides of the split, and would have to exit from both openings. I saw the mess from only one opening. The inside of the rear case shows no sign of any fluid other than what I spilled taking things apart.

I lifted the unit out of the housing again, had it hanging on the hoist for a while studying the situation, looking for some signs of a possible place for a leak. I was again unable to come up with one. Everything looks dry except for what I spilled in the process.

I'm about to accept the fact that I must be just plain STUPID. There IS no leak. What I saw running out on the floor must have been nothing more than petroleum condensation. All this hassle and all I managed so far was to damage a $40 seal and a couple O rings. I think when I get the seal and O rings changed out my next move will be to try to add a small amount of air pressure into the case drain port to see if that shows me anything. If not, I may be forced to give up the search, clean it all up, put it back together, try it again, and hope for a better outcome.

Maybe check to see what the tractor has for fire insurance coverage. With all the heat being generated here, the thing may well ignite.

 

[K5lwq]

Maybe check to see what the tractor has for fire insurance coverage. With all the heat being generated here, the thing may well ignite.

I have been there before! Sometimes jobs just fight you the whole way. Next time same situation and goes together no problem. Thanks for the update.

 

[NUTFARMER 1]

Weird thing is if you type in the part #s it may come up with a 2 letter prefix and list for Cub Cadet or show as a kubota part. Is there a chance the wrong fluid was in the hydrostat making it sticky?

 

[K5lwq]

Any updates Harry?

 

[Harry in Ky]

Any updates Harry?

No, not really. I've kinda been avoiding it finding other projects more satisfying. The more I study this thing and the more I look at it, the more confused I become. For instance. The seal I messed up while taking it back apart is at first glance the input shaft seal for the hydrostat unit (but not really). This shaft fits through a bore in the casting of the clutch housing. There is a sleeve that centers and supports the front of the hydrostat unit case into the clutch housing casting. On the front side of the casting is the actual input shaft that mates to the flywheel flex plate. That shaft drives another gear below it which the first shaft I mentioned is splined into, through the earlier mentioned sleeve. So both these shafts, and the gears between them turn with the flywheel. The shaft and gears on the front side are sealed in an aluminum housing bolted to the front side of the clutch housing casting. There is a seal on that shaft, (which was replaced) and a gasket between the aluminum housing and clutch housing (which we can't get). It's the sleeve that confuses me (this time). The sleeve is sealed front and rear on its outside with O rings. The unit case and the front side aluminum case are both full of oil at all times. There is an overflow tube fit through the casting near the top connecting both these oil filled entities. The sleeve has a seal (the one I replaced twice) on the unit input shaft facing the rotating groups. Not far from the seal is a hole through the sleeve maybe 1/8" or so in diameter, maybe less, that connects both reservoirs together so oil flows freely from one to the other regardless of what the seal does or doesn't do. As i'm putting this part together for the second time, I'm looking at it wondering what the hell difference does it make if this seal is any good or not? I guess there's some logic to it, but so far it escapes me.


I think tomorrow I'm going back out there and start the process of making it one piece once again. I can't say I have a great deal of confidence that it won't do the same thing it did last time, but what else can I change?

It's either going to work or it isn't.

 

[Harry in Ky]

Not much to add today. The tractor is back on four feet again, lines hooked up (enough to run it anyway), pedal linkage is back together and the oil poured back in. Once the unit was back in the housings I sprayed everything I could get to in the dry areas and blew it all out so virtually no oil should be there. The hole it was leaking through last time is clean and dry. So far.

The floor plate, steering column, and all the wiring mess are still in pile on the floor. Next step is some creative wiring to get it start and run in place. I guess I could have done that today, but my confidence level in this is pretty low right now, and I didn't want to go home mad. I'll save that for tomorrow.