D Series Hydro motor gasket question

[coldone 35]

Can any body tell me the thickness of the original gasket for the housing?

Long story short, had to flip my housing 180 for correct travel. Old gasket got destroyed in process. Homemade gasket too thick, creating too much clearance between cylinder block and valve plate. I am not sure if the gasket the destroyed was original or not, the PO had been in there before.

Thanks

[Trouty56 567]

There seem to be a lot of instances of that drive motor housing needing flipped. Beats me why they even made it that way. I guess you are talking about the housing gasket. Pretty thin if I remember correctly. Been 3 years since I had to flip mine when I bought the tractor.

[pfrederi 17,741]

That must be a pretty thick gasket that was added. There is a heavy coil spring inside the piston block and the nature of the hydro pistons should cover minor gasket thickness differences. (You sure there isn't another issue here???

I am picking up a pump housing gasket from my dealer today...I will measure it can't believe there would be much difference in the thickness of it and the motor gasket.

[coldone 35]

For the gasket i made, I only had cork material 3/32 thick. Wasnt thinking about shaft end play. I now have the thinner gasket material. Just wanted to make sure that it wasnt a paper gasket thats supposed to be in there.

[pfrederi 17,741]

3/32 is a bit thick.

Pump Motor gasket I just got measured .0185. FYI the motor to transaxle gaskets are about .031 (1/32") and they are notably thicker than the pump housing gasket. The last few transmission case gaskets i got from toro come as a cutout but the entire center section is still there unmolested. it measured about .017....I laid it out and you should be able to get your motor gasket out of that piece if you happen to have one. Also see Mcmaster 9470K25 or 9402K21

I hope it is just your gasket, so far my experience with hydro parts that have been opened by the PO is not good.

[coldone 35]

Well it aint the gasket. I managed to find some material locally that is the correct size and I changed it out today. The symptoms are still the same. looks like i will have to go deeper. I did get a look at the motor valve plate and didnt think it looked bad but i was in a hurry.

So how do you isolate if its the pump or the motor? I am guessing i will have to fab a block off plate and block off the manifold. Then try to push the tractor.

[Hodge71 664]

I agree with Paul... When I hear the PO was in something, especially hydro untis, it scares the heck outta me. My 18 auto was a mess when I bought it. I cleaned it up and realized it was covered in blue silicone on the inside and outside and I was told the PO wasnt in it. Yet, there were no factory gaskets, just blue goo all over everything and a huge hole in the bottom of the differential that was filled with JB weld. I'm wondering what exactly your machine is doing that you needed to flip the motor? All the info you can give us will help us help you. Paul is one of the best hydro guys on here. He taught me, and we have torn a few motors and pumps apart together now. I think we might be able to point you in the right direction.

[pfrederi 17,741]

Sorry to hear that. If the PO put the housing on upside down it sort of indicates he didn't know what he was doing (in which case you wonder what else he missasembled) or he found major problems too expensive to fix and he just quickly closed it up.

Time to drag out the manual. it actually has fairly detailed diagnostics. I have never figured out how to definitively ascertain which is at fault (pump or motor) once you eliminate the charge pump as the problem.

Some thoughts and I hope Jeff will jump in here.

Charge pump testing requires a hydro pressure gage...(or if you have a three point hitch and it will pick you or a heavy load up fairly quickly... or a heavy mower deck on the midmount) we can make an assumption (remembering what assume means that the charge pump is good enough.

Depending on the nature of you malfunction the diagnostics will have you look at several things acceleration valves check valves etc. However in the ones I have looked at the problem is normally cause by dirt in the system that wore or damaged the slippers and valve plates. If that is the problem then I can virtually guarantee you will have to open up both pump and motor. the dirt circulates through the whole system and will wear out both ends.

Hopefully your problem will be simple like a bad tow valve.

What are your symptoms???

[coldone 35]

I managed to get the WH put back together a few days ago. When it first went back together, the tire rotaion was opposite of the direction controls. I tracked this down to the motor housing being off 180. I managed to flip the housing to the correct postion. In the process I mangled the old gasket and had to make a new one. I only had 3/32 cork on hand for the material. Everything seemed to work fine after that. I have pulled a trailer with 2000lbs of slate on it. I put about an hour on the tractor, nothing too strenious as I wanted to let the new oil circulate and flush the system.

This weekend I changed the oil (10W30) and filter on the system. I did manage to over fill it but I drained the excess out. I purged the system best I could, wheels off the ground and working the controls. I hooked up the plow and tried to plow. The tractor wouldnt even get it into the ground. It would barely pull itself out of the furrow in either direction. The engine never changed tone. I then tried it on a hill, same results. The system was whineing very loudly.

I consulted the manual and gave the tractor the push test. With the push valve closed, I could push the tractor easily. I knew that the motor had been opened up before, and the first thing on the troubleshooting list is to check the acceleration valves in the motor. I did check and they were ok and in the proper positions. I did not take the valves apart, just did a visual.

I saw in the manual that the implement valve is plumbed directly off the charge pump. So I procedded to load up the 3PTh to see if it had pressure to lift heay loads. It could do 300LBS with no problem.

The motor slippers looked good, shiny, no scratches, no rounded edges. The valve plate, I did not check throughly, but I did not notice any gouges.

This machine has 200 orignal hours on it. It blew out the pinions in the diff and has been sitting for 10+ years. The PO had taken the transaxle apart, purchased repair parts and never reassembled. He died and the children wanted to get rid of the tractor. No one knows what has and has not been done or how he blew the diff.

Here is my logic on blocking off the motor to manifold connection. Open for corrections.

I would think that blocking off the motor connections, so that the system could not pass oil back to the pump section, and trying to turn the motor by hand would not create enough back pressure to do any damage. Basically it would dead head the motor just to see if the oil bypass issue is in the motor itself. If there is no (low) bypassing in the motor cylinder and pistons i shouldnt be able to move the motor output shaft much, just enough to take the "slack" out of the fluid. Due to the visocity of the oil I may have to dead head the motor and see if the tractor can be pushed. That would simulate the push valve being closed and a properly operating pump, then trying to push the tractor. If the wheels lock up and dont allow the the tractor to role, then I know that the bypassing issue is not in the motor.

I still need to check the push valve, it seats a little funny to me. I pulled it the other day to give it a visual and it looked ok, but it dosent feel quite like the one on the d160.

[pfrederi 17,741]

well sounds like the expensive stuff is ok.

You might try substituting the push valve from your D160. Hopefully that will solve it (shine a light in to check the seat if you can)

If no improvement I would take a second look at the acceleration valves. You will have to pull them. There is a teeny tiny hole in the side of the threaded cap (metering cap). I could barely see mine The smallest wire on my welding torch cleaning set was too big... I had to borrow a fine needle from the wifes craft stuff. There are also three springs one between the valves and one inside of each one that could be an issue.

[wheeledhorseman 574]

I'm still very much learning from the other guys here and also from discoveries I've made trying to resolve an issue with the hydro system on my D-200. If I follow you right it was working ok with the new gasket till you changed the oil and filter having purged the system of oil. The system now makes a whining noise and limited power.

Ok - I've just recently refilled the system on mine having pretty much removed every last drop of what was in there judging by the quantity I got out. I also swapped out the lift valves as one was broken and found the hoses to be empty. Also changed the filter.

Refilled the tranny at the back making a huge mess as I thought I'd be able to get more in at the first filling than was possible. Sorry this is in metric but It overflowed with about 4.5 litres in it. Having mopped up the mess it erupted again as an air pocket glooped up the tube.

I didn't lower the level before starting her up as there was nowhere near enough oil in it yet (based on the Sundstrand data) just put the stick back. After fast idling for a couple of minutes the level was way below the dip stick so topped up again. Had to do this a third time before it was about right on the stick.

Everything seemed to work ok (except reverse which is the ongoing issue with mine) but operating the lifts and making it go forward it whined. In the case of the lifts the whine was clearly coming from the control valves I'd swapped out so I assumed it was air in the system passing through the valve. It lessened the more I operated them but didn't exactly go away.

Left it till the next day - it whined a bit but much less and gradually the noise diminished. The day after it was quite quiet as it had been before draining out and refilling. Oh and it did need a final top up again.

I'd read somewhere on the forum that these should automatically purge the air when you run them but on mine it wasn't anything like an immediate process. Hope my experience may be of some use. There's a lot I've also discovered about the accleration valves Paul mentioned but I'll save that for another time.

Andy

[coldone 35]

If I follow you right it was working ok with the new gasket till you changed the oil and filter having purged the system of oil. The system now makes a whining noise and limited power.

I am not sure that it was working correctly before the oil change. I had just gotten the transaxle reassembled after it had sat in pieces for 10+years. I found out the housing was upside down and changed it and gasket. After that I babied it for a total of an hour over a week. The only strenious thing I did was pull a loaded trailer a total of 20 feet. After that hour of run time I changed the oil, then I really tested it by trying to use the plow and going up a very steep bank. But while reading your reply and typing this, I guess i should test it again with the trailer. If it cant pull it now then we know its the something related to the oil change.

Refilled the tranny at the back making a huge mess as I thought I'd be able to get more in at the first filling than was possible. Sorry this is in metric but It overflowed with about 4.5 litres in it. Having mopped up the mess it erupted again as an air pocket glooped up the tube.

Yep did that.

I'd read somewhere on the forum that these should automatically purge the air when you run them but on mine it wasn't anything like an immediate process. Hope my experience may be of some use. There's a lot I've also discovered about the accleration valves Paul mentioned but I'll save that for another time.

I think I will be rechecking my level soon.

If you have any links to the discussions on the valves Please post. Maybe save somebody some typing.

Thanks

[Trouty56 567]

Coldone...double check the valve plate to be sure it is seated properly. The first time i opened mine up it was not correct when i put it together. I had the same symptoms.

Excuse spelling errors...using "dumbphone"

[wheeledhorseman 574]

As it's your thread I'll put what I discovered here.

It's part of an ongoing hunt for what's responsible for the fact that my D will do everything except go backwards.

The Sunstrand service manual is pretty good on instructions but important to clean the whole area round and above the big hex retaining thingies so that muck doesn't fall on the valves as you pull them out.

The valves looked like this but the spring shouldn't look like this - it was in four pieces, one of which had wound inside another.

The valves may look the same at first site but there is a difference between the forward and reverse valves explained in the service manual. One has a bigger flat machined into it than the other. In the end of each valve assembly is a spring valve with tiny spring retained by the hex bolt like bit. Also the tiny pin hole Paul described.

I won't try and go through all the detail as its important to read and understand what is said in the manual first but here's some things I discovered.

I replaced the spring and reinstalled the valves pleased that I'd found the fault.

The horse still wouldn't go backwards (big disappointment)

Took the valves out again then reassembled without the big spring and was surprised to discover that the valves will work without it.

I'm not saying they work correctly as you don't get the damping effect but it went forward just fine.

Although I'd checked the tiny pin holes were clear and that the spring loaded valves in each bobbin were working you kinda get paranoid at this point (or at least I did). So checked them over again, found nothing wrong, so to prove a point put the bobbins back in each others place.

Made another discovery - even though the reverse valve was now on the forward circuit and vice versa the tractor still went forwards! It proved a point in that both bobbins with their valves and pin holes worked. I'm not saying though that it therefore doesn't matter which valve goes where - it does! Just that if a PO has put them back in the wrong places it won't necessarily stop the tractor from moving.

The manual has a very good fault diagnosis section which identifies the things to check and the order of checking them so I wouldn't jump in and pull these valves for inspection till the right time.

Working clean is very important a tiny speck of grit can trash the system. I cleaned the bobbins off with some of that fast evaorating spray before installing them each time to be certain sure.

When you remove the valves there is a small oil loss so be prepared to catch it but don't panic the whole tranny won't empty - just a bit that's in the motor.

I'm sure some of the other guys who know more than me will jump in if I've got anything wrong here.

Hope it helps in some way.

Andy

[Hodge71 664]

Cold one,

I have to agree with Paul, Andy and your observations and ideas. I would do the push valve test. That should either eliminate the internal fluid bypass in the pump theory you have. I would also check that tow valve especially when youre saying something is hinkey about the way it seats. If it looks ok and the internal seating surface is marred then I believe your goose is cooked. I dont think you can replace the internals Try pauls idea if checking your other valve for the 160. If it works in yours you might be good to go. Also have you tried to pick anything heavy up with the 3 point or mid lifts? It might be easier than plugging a pressure gauge in. I know its now the same as actually having a pressure reading, but its a quick check. If either dont lift any weight then I would get a pressure reading and check the manual. Have you checked your valve plate? I know Bob mentioned it also. It sounds like so much to do but by doing the simple things first maybe you'll find its an easy fix and wont have to tear things down further. With 200 hours I find it hard to beleive your pump is worn out but theres an issue somehwere. I dont want to insult your intelligence either but are you sure theres no air in the system anywhere? The only reason I ask is that after I changed my lineset out because all I was told was that I needed O-rings, my system "screamed" for quite awhile afterwards due to air in the system. I had my 18 auto blocked off the ground and continuously moved my motion control from forward to reverse for about an hour or more while leaving it run for extended times in each direction. Eventually the whining went away but the mid lift couldnt lift snowplow. I left it sit overnight and was surprised at how low my oil was the next morning. I added another quart and a half to the system. Started the tractor and the lift was no better so I kept moving the lever back and forth to bleed the lift cylinder of air. It eventuall was able to pick the plow up. Driving it though ended up proving to me that my pump and motor was shot as the tractor stopped moving once it got hot.

[wheeledhorseman 574]

I meant to include this in the last post but forgot.

I've tried the push valve test on mine and really wasn't sure what to make of the results I got, particularly as I'm losing pressure somewhere when the tractor tries to go in reverse.

Having run the tractor and the turned it off, it cannot be pushed in either direction (which seems odd given the fault) until the push valve is opened.

With the valve open it can be pushed either way - there's a bit of resistance, it doesn't exactly 'free wheel'.

Now for the second odd thing. Close the valve again and you can still push the tractor in either direction with some resistance.

I don't know if that's normal or if it has to do with the fault mine's got - wherever it is.

Andy

[coldone 35]

particularly as I'm losing pressure somewhere when the tractor tries to go in reverse.

Andy, have you checked the check valves? The check valves are not shared between the forward and reverse circuits. If the one for the reverse circuit is not seating, it would let high pressure bleed over to the low pressure side while not effecting the forward circuit. In the forward motion, the reverse check valve is not in operation, it is totally in the low pressure circuit.

I will have to give the push test another try. I did swap the push valve out with d160s. I had no change on the d200.

Since mine has lost power in both directions, I am trying to figure out what both circuits have in common in a high pressure situation. I dont really see a way for the accel valves to effect both direction unless both metering valves are stopped up (possible). I can see how if the cylinder block is not seating against the valve plate there can be massive leakage and bleeding directly over. Bottom line is that i am just going to have to pull the motor and inspect everything. This isnt going to be a quick fix. I will probably have to put this on the back burner for a awhile. At least until I can take my time and do it right. I have too many things going on ATM and not enough time. I will keep this thread updated as I make progress. Please keep the suggestions coming.

[wheeledhorseman 574]

Agreed on the acceleration valves - mine's a reverse only issue so they were suspect but I've eliminated them.

They're unlikely suspects in your case hence my comment about not rushing to pull them as a first job.

Also eliminated the damper valves buy removing them from the circuit and blanking off the ports on the motor.

The reverse check valve in the pump is the major suspect and the first thing I tried but like Paul and Jeff found the cap that retains the spring an ball takes some undoing. As I was beginning to destroy the slot in the cap I've left it till last but will have to revisit.

Paul's sending me a cap, ball and spring from the pump he used as a training aid. Although I gather the cap is a bit mangled it is out so if I damage the one in mine getting it free I'll have another to put back.

I'm 99% sure it must be the check valve based on hours pondering over the flow diagrams in the Sundstrand schematics but those are famous last words. For the moment I'm concentrating on finishing the resto - it's been a long one so in a way I'm not rushing to fix the reverse fault as at least it does go forwards and lift things on the hitches. I've had no opportunity yet to make it work hard for any time at all so there may be issues that I haven't discovered. It's been best not to think too much about that.

I have found it just so useful the way a group of D owners have got together over the last few months and are prepared to share what they've done and discovered. Restoring one of these can be a daunting, lonely, and at times, discouraging thing to do unless you've got others to

talk and share isues and ideas with. So thanks guys

Andy

[Hodge71 664]

Our one big disfunctional "D" family .... Glad I'm part of it!!! :party:

[pfrederi 17,741]

particularly as I'm losing pressure somewhere when the tractor tries to go in reverse.

Andy, have you checked the check valves? The check valves are not shared between the forward and reverse circuits. If the one for the reverse circuit is not seating, it would let high pressure bleed over to the low pressure side while not effecting the forward circuit. In the forward motion, the reverse check valve is not in operation, it is totally in the low pressure circuit.

I will have to give the push test another try. I did swap the push valve out with d160s. I had no change on the d200.

Since mine has lost power in both directions, I am trying to figure out what both circuits have in common in a high pressure situation. I dont really see a way for the accel valves to effect both direction unless both metering valves are stopped up (possible). I can see how if the cylinder block is not seating against the valve plate there can be massive leakage and bleeding directly over. Bottom line is that i am just going to have to pull the motor and inspect everything. This isnt going to be a quick fix. I will probably have to put this on the back burner for a awhile. At least until I can take my time and do it right. I have too many things going on ATM and not enough time. I will keep this thread updated as I make progress. Please keep the suggestions coming.

Good Luck!! If you find you need any small parts (check valves etc) let me know I may have some. We D types have to stick together

[JamesBe1 82]

I have found it just so useful the way a group of D owners have got together over the last few months and are prepared to share what they've done and discovered. Restoring one of these can be a daunting, lonely, and at times, discouraging thing to do unless you've got others to

talk and share isues and ideas with. So thanks guys

Andy

I heartily agree. The collective knowledge here is somewhat inspiring. Restoring one of these is indeed a daunting task sometimes. I have made several mistakes, and have learned a great deal from them. I got through most of the problems much quicker with everyone's input. Some problems I might still be working on (I don't give up very easily).

I think also that a lot of the hydro knowledge here transposes nicely to the other WH hydros, and is beneficial for anyone with any type of WH hydro. I know that the knowledge gained here is and will be helpful with keeping my C-145 running.

Much thanx to all (I will leave out all of your names) who contribute here. I only wish that I had something of value to contribute besides encouragement. Oh well, maybe some of you can learn from my mistakes.

James