Erratic Sundstrand Series 15

[bc.gold 3,399]

Rebuilt hydro worked good first week then started acting up, sometimes the tractor moves forward and will not reverse when selected to do so, sometimes it's reverse and no forward and no neutral when selected.

 

Changed the filter, drained the hydro fluid then installed fresh, works fine for awhile then goes goofy, from the repair manual the problem appears to be something amiss with the acceleration valve.

 

I think the spring may have broke and needs to be replaced, fortunately I have a few spares.

 

The unfortunate part is the tractor almost ran me over, yea I leaned over to reach the ignition switch to start the engine thinking it was in neutral, when the tractor started it lurched forward the rear tire grabbed my right leg knocking me off my feet. And this is all taking place inside the shop which has limited space, as I'm on the floor busy scrambling to stay out of reach of the rear tire  and trying to get at the key the tire grabs me by the rig cage.

 

The leg feels much better but it sure hurts to take a deep breath, sneeze or cough, may have cracked a rib, I'm thank full that I had removed the snow chains otherwise my clothing would have been sure to have been snagged.

 

At 70 years of age I found that I can still move pretty fast when needed.

 

Now to repair that faulty acceleration valve.

 

 

Edited April 23, 2019 by bcgold

[roadapples 6,981]

Glad it wasn't more serious...

[bc.gold 3,399]

2 hours ago, roadapples said:

Glad it wasn't more serious...

 

Me too, my life did not flash before me all I was thinking at the time was to reach that key and what damage the tractor was going to do to the rear wall of the garage. Tractor veered to the left and came to a stop when it made contact with an old office desk that I use for a work bench.

 

Then it just sat there spinning its rear tires waiting patiently for me to turn the ignition off, this was the first sign of any trouble with the acceleration valves so the whole incident was quite unexpected.

 

All the safety switches have been previously disabled by previous owners not to say that I would have done the same as I really hate them.

 

Last summer Pat took the small electric mower over to another property we have in another town when she came back home told me the mower would not work. Duh, honey to have to squeeze this handle right here before engaging the electric switch. Curious if she remembers this year.

Edited April 24, 2019 by bcgold

[Sarge 3,462]

Any time that I suspect there is a problem with the direction control on a hydro system I will not run any tests unless those tires are securely off the ground and the front wheels blocked solidly. I've had mine run away a couple of times when I first got a WH - that was scary having something that weighs nearly a 1,000lbs with no operator. These things have been known for going through garage walls, sheds, bushes and fences pretty easily with the pulling power and traction. Most people don't consider what they are capable of doing due to their size - but they should be treated as any large piece of equipment when testing things and trying to figure out an issue. That spring between the two valves can get weak as well as debris can be floating around inside those valves and randomly blocking the ports - which will cause erratic behavior. I had the same problem with my C-160, replaced both valves as well as the spring and it operates like new now as it should.

 

You might want to very closely inspect the direction control arm, bearing and all the associated parts as well for wear - those can cause some real headaches with trying to hold that hydro arm steady enough to keep the thing in that neutral position. Even the later model Eaton has quite a short throw length on the direction control - which is why these linkages are so sensitive.

 

Sarge

[bc.gold 3,399]

Both Simplicity and the Allis 720 have on the control arm a large nut with a pointed head when extended fits into a hole on a bracket attached to the Sundstrand this assure the transmission remains in neutral while adjusting the linkage to the hand operated direction control.

 

The hand control when properly adjusted had a ball bearing that fits into a detent locking  the transmission in the neutral position, to move forward or in revers you have to squeeze the release lever along with the motion control handle to move it in the direction of your choice.

 

A shipped from the factory there would have been a safety micro switch located at the transmission side in addition another located at the hand control to prevent starting the engine if the transmission were not in neutral.

 

The acceleration valves if the spring is broken or a bit of dirt is causing the spools to hang up, the neutral position is not recognized, you'll experience erratic transmission performance or none at all. In my case the tractor decided to move forward while it was in neutral/

 

Since changing the hydro oil have put about an hour or so on the tractor, most of the time the transmission is behaving but still hangs up on occasion. Either the spring has become weak or broken of there is a burr on one of the spools causing it to hang.

 

 

Edited April 24, 2019 by bcgold

[bc.gold 3,399]

Sundstrand Hydro now works perfectly, the problem was a combination of things that have now all been corrected.

[bc.gold 3,399]

5 hours ago, bcgold said:

Sundstrand Hydro now works perfectly, the problem was a combination of things that have now all been corrected.

 

Well this is certainly turning out to be a real puzzle, after reinstalling the acceleration valve worked he tractor back and forth for half an hour with out any issues. Then the same problem shows up, stuck in reverse or sometimes forward no matter how far the forward control is advanced.

 

Incidentally the acceleration valves have nothing to do with motion or direction of travel, their main purpose is to cushion the sudden blow from a change of direction by bleeding off some of the oil flow to soften the transition.

 

[bc.gold 3,399]

When I purchased the seals, gaskets and bearings for this Sundstrand rebuild had doubled my order so that I could rebuild the hydro in my Simplicity 9020 as well.

 

As for dear old Alice I may have figured out were I went wrong, the motor and pump assemblies look identical the splined input and output shafts easily fit either. If you measure the cylinders they appear to be be clones, from spares that I have remeasured this evening found the differences are internal.

 

Of the three cylinder blocks that I measured this evening the spine shaft fits deeper into the internal spine giving about a 0.040 difference but have no way of knowing at his point which are pump cylinders or motor.

 

It took much to long to do the rebuild parts were all kept in a box, then to make matters worse purchased another Sundstrand for a much needed part which now added to the motor and pump cylinder collection. And don't forget the Cub Cadet that donated a few usable parts like another pair of pump and motor blocks.

 

At this point I'm placing my bet that I have installed either a pump or motor cylinder at the wrong end, time to overhaul the Simplicity 9020's hydro this time placing the parts out in order. From this I'll be able to identify the pump and motor cylinders then properly mark my spares as such for future use.

 

Just remembered that I have the damaged motor cylinder from previous owner having towed the tractor, heading back to the shop.

 

 

 

Edited April 25, 2019 by bcgold

[bc.gold 3,399]

It's now obvious the differences between pump and motor is on the internal splines.

 

 

[bc.gold 3,399]

Top row is motor cylinders bottom is pump, follow the bean under the shell. The two missing cylinders which have been identified as pump cylinders have both been installed during the Sundstrand rebuild.

 

I have mistakenly installed a pump cylinder on the motor end of the hydro.

 

[bc.gold 3,399]

Hopefully stuck check valve.

 

 

 

Edited January 18, 2021 by bcgold

[bc.gold 3,399]

On 4/24/2019 at 2:13 PM, bcgold said:

Sundstrand Hydro now works perfectly, the problem was a combination of things that have now all been corrected.

 

Less than a week then  the tractor tried to run me over.
 

Changed the spools and the spring no burrs on the spools and they slide easily inside the bore.

[bc.gold 3,399]

Found the issue causing erratic hydro performance the roll pin has sheared off leaving just enough meat to catch every so often to allow movement on the swash plate.

 

This is the reason the transmission would either not go into gear or stick in forward or reverse.

 

 

Edited April 27, 2021 by bc.gold

[stevasaurus 22,229]

If you did crack a rib or ribs and it hurts to cough...try rolling up a towel and tucking it under your arm on top of the ribs when you feel like coughing.  Hold the towel hard with your arm.  It eases the pain significantly.  

[bc.gold 3,399]

Problem found and solved others should take note, one side of the swash plate uses a roll pin in halves., reason is a longer pin will not push out for removal but half a pin will drop nicely into a pocket cast into the housing.

 

Both halves have the length the control shaft, with the first pin enclosed inside he shaft the second pin installed flush with the top of  the swash plate perhaps entered into the intended hole maybe a thousands of an inch or so.

 

Think of a lock tumbler that will only turn once all the tumblers have met the shear line.

 

This installation error caused  the erratic operation, the hydro shift arm indicated neutral but unseen inside the swash plate was set for either a go no go..

 

The improperly installed roll pin halves on occasion would connect enough to have forward and reverse but the transmission would often stick in either direction no matter where you shifted the transit lever.

 

Edited May 23, 2021 by bc.gold

[bc.gold 3,399]

Old age claims another victim, after making the roll pin repair and putting the hydro back into the tractor it did not work. Pulled the trans axle and hydro out once more, upon examination could find nothing wrong.

 

Half expecting the hydro would be pulled again decided not to install the bull gears and tires, to hasten filling the transmission with hydraulic fluid removed the top cover.

 

With just the axle stubs installed I fired up the engine then engaged the hydro, no motion at the axle stubs but could see inside the transmission that the pinion gear was churning up the oil.

 

The Alice 720 has a three speed trans axle, I was focused on the hydro and did not notice the transmission was in neutral.

 

I'm a tad embarrassed but at least the new Milwaukee saved the day.

[bc.gold 3,399]

Alice left me for greener pastures, I hold no animosity towards her for wanting a much larger acreage where she'll be able to stretch her legs, she took along her 3 point rototiller, snow thrower and her belly deck. I was kinda sad watching her load these things onto a trailer with her ARC 700 front end loader.

 

The new owner has a lifetime supply of spare parts saved from the Simplicity 9020 I had cut up. All she left me are a bucket full of Sundstrand parts which I now have no use of.

 

I've spent hours tutoring him with instructions both operational and on safety, I've never before felt this way of something I have sold but I should have had him sign a waiver.

 

 

 

 

[45fmj 1]

changed trans. in toro 322d was working but wouldnt raise deck or steering not great.

installed good working 325d trans and installed it in 322d with minor filter changes.

works good but goes in wrong directions forward and reverse??

any ideas?

[stevasaurus 22,229]

@45fmj  Welcome to Red Square.  Please start a new thread about your issue in the "Transmission Section".  You will get much better and more answers then posting in an old thread.  Thank You. 

[bc.gold 3,399]

On 3/8/2022 at 10:31 AM, 45fmj said:

changed trans. in toro 322d was working but wouldnt raise deck or steering not great.

installed good working 325d trans and installed it in 322d with minor filter changes.

works good but goes in wrong directions forward and reverse??

any ideas?

 

Possibly reversed hydraulic lines gong to wheel motor supply

[45fmj 1]

axle is reversed in 325d??