Hydra Power Woes

[farmersamm]

Getting real frustrating around here. Spent almost a year overhauling the baler, ready to rock(although late), and now I gots tranny problems.

The Hydra Power unit has been acting up for over 12 years. Slow to shift into direct drive(high side), and accomplishes the shift with a back breaking lurch. I used to use the clutch between shifts, to soften the blow, but now the unit has to be running full tilt to engage the clutch for direct drive.

Most of the time I'm running in Hydra Power Drive(low side), but do need the high side to road the tractor, and will need it to run the new disc mower due to faster cutting speed/ground speed.

Changed out the filter 2 days ago...........and the doggone thing quit shifting into the high side(direct). And........the unit is getting hot as a pistol. 'I'll put an IR thermometer on the unit today. I believe max oil temp is 225*F,

Ran the sucker this morning to see if temp had any effect............sure enough.........shifts fine at pre warm up temps. Ambient is around 70* this morning. Smooth as silk.

My first thought was that the new filter wasn't flowing right. It's a full flow filter with a 7ish psi bypass. HOWEVER........looking at the oil schematic for the unit, there is a bypass passage which takes oil around the filter, and runs it directly to the bearings for lubrication. Oil doesn't run through the filter when the clutch circuit is in play.

So now........after this morning's test results(unit shifts properly), I'm thinking I have a pump problem, spool seal problem, spider seal ring problem......or anything that might be dropping oil pressure. The pressure is spec'd 140-190psi for the clutch circuit, and 20-60psi for the lube circuit.

Seems to me that if it operates when the oil is cool, we're lookin' at a viscosity indicator. Cooler oil, higher viscosity..........which goes away when the thing gets up to operating temp. The pump will move the higher viscosity oil, but falls on its face once the oil gets hot.

Need to put a pressure gauge on it today to see just what's shakin'.

What fluid in the tranny you might ask. NOS genuine Type A. I hate to have to drain it...........I'm not totally confident in Dexron/Mercon as a replacement. I exhausted my source for the Type A.....guy died, and business bought out. So.......the fluid ain't the problem I'd wager.

This is the early style Hydra Power that has a heat exchanger on the unit for cooling. The engine coolant is running at a normal range, fan belt tension to be checked today.

I personally don't give a rat's patoot about shifting into high right now. I need to get in the field. WHAT I AM CONCERNED ABOUT IS THE LUBRICATING CIRCUIT, AND HEAT BUILDUP. I can live with a slower ground speed if need be, I can't live with tearing up the internals for lack of lube, or excessive heat.

 

[farmersamm]

Can't get the pressure test plug out. About par for the course. Nothing on this thing is easy to work on. My Allis is a dream to work on.

Might have to weld a nut on the plug. Toast some marshmallows when it goes up in smoke.. Why not(shrug). Been thinking of gettin' out of the biz anyways.

 

[farmersamm]

She's sorta down in there. Like just about everything else on this thing. Although I gotta say, back some 25yrs ago I was able to resleeve a cylinder due to the bathtub frame design. Full oil pan access from underneath.

A stinkin' $1 pipe plug...........and I've got a big green paperweight. Never thought the ol' gal would die this way. Expected something more dramatic.

The heat exchanger shows around 195* after it's warmed up........at which point the 2spd becomes inoperable. Without being able to see how much pressure is in the lube side of the system, I can't run it.

Doggone near impossible to weld a nut on the plug. If you can't see inside the hole, you can't do a good job ensuring there's been adequate fusion. If the nut pops off, good luck cleanin' it up with a grinder down in that hole.

Both backup tractors have seized motors. Tain't lookin' good. Get a custom cutter in here, and you lose 2/3 of your hay crop........plus the dooods ruin your fields by cutting too low to the ground. Might be time to call in some favors, and borrow a machine. Or cash out.

Kept this old iron running for 30yrs. I guess it's caught up with me.

 

[Olliejunkie]

Been many years since I worked on one. Ended up buying a used one and switching it out. What I did learn I can't remember.. sorry not much help. If you could find a good one probably swap it out in a day or two.

 

[RCP]

Although it is possible that the pump is worn, it is not a normal failure mode, the pumps are pretty stout. More likely is that there is a problem with the cast iron seals inside of the hydrapower. The fact that it pulls in under mode is good, it means the sprag bearing is still good. The clutch pack could also be worn which would also be consistent with the symptoms you mentioned. You might squeeze a few more hours out of the unit by substituting some heavier oil, but eventually you will need to rebuild the unit. AGCO has jacked the prices on the parts to do the rebuild, you will have $500 in just the seals and gaskets.

 

[farmersamm]

Although it is possible that the pump is worn, it is not a normal failure mode, the pumps are pretty stout. More likely is that there is a problem with the cast iron seals inside of the hydrapower. The fact that it pulls in under mode is good, it means the sprag bearing is still good. The clutch pack could also be worn which would also be consistent with the symptoms you mentioned. You might squeeze a few more hours out of the unit by substituting some heavier oil, but eventually you will need to rebuild the unit. AGCO has jacked the prices on the parts to do the rebuild, you will have $500 in just the seals and gaskets.

I agree. It's an out of tractor job. I think I might just be able to do the pressure test despite the test plug being chowdered. I saw the price on the rebuild kit.....Holy Moley.

 

[farmersamm]

I'm on the canvas, but I think I can get up. If I can test the pressure flowing through the filter base(that plug ain't comin' out unless it's on the bench), I can see if the bearing lube circuit still has enough pressure to run long enough to do my hay.

I was trying figure out how put a tap/nipple on an oil filter so's I can run a guage. Looked around the Net, and saw the KD tool that allows you to take pressure directly off the filter base.

Few drops, some old filter gaskets, and a nipple..............and I'm in bizzzness!! Fire up the lathe in the morning. I have a suitable guage, so the only out-of-pocket is having the hose guy make me up the proper hose/fittings.

 

[farmersamm]

Old Sam ain't gonna spend almost $200 https://www.wiseautotools.com/kd3289-gm-oil-pressure-test-kit-tests-from-oil-filter-port/

Pretty simple lathe job.

 

[RCP]

If you can find a a way to check pressures, it is possible to remove the regulating valve and inspect it and adjust it in the tractor. It is not fun but doable. If you want to see some excellent videos, look up Chris Losey the Oliver Guy on YouTube.

 

[carolina oliver]

Your early post seems to indicate that heat/cooling may be an issue. I have a comparable tractor, 1650D w/ hydra-power. I'm at least 3rd owner. While doing routine checkup, maintenance etc I found cooler was severely blocked w/ crud. Ran garden hose thru it a while and cleaned good.. I've never had any issues w/ shifting etc. Cheap thing to check.

 

[farmersamm]

Your early post seems to indicate that heat/cooling may be an issue. I have a comparable tractor, 1650D w/ hydra-power. I'm at least 3rd owner. While doing routine checkup, maintenance etc I found cooler was severely blocked w/ crud. Ran garden hose thru it a while and cleaned good.. I've never had any issues w/ shifting etc. Cheap thing to check.

There isn't much that you can maintain on the heat exchanger. All cooling is done by circulating the transmission oil through a water jacket that contains engine coolant coming straight off the water pump. I suppose you could dismount it, and flush the oil lines, and jacket.

To be honest, until now, I've never checked the oil/heat exchanger temp. Never had any issues that brought it to mind. For all I know, I might be running at the correct temp. Max is 225, and I'm sitting at 195 on a day that was up around 104*. Although the tractor was not loaded in any way.

 

[carolina oliver]

I referred to flushing out the water/cooler side that was stopped up on mine.. This is what then cools the oil. Easy to do..

 

[farmersamm]

I've never had problems with engine temps(or engine oil temps that I know of). It's been a good system. The only issue is the perceived heating issues with the Hydra Power. Again, I need to stress..........the only means of cooling the Hydra Power oil is the heat exchanger in the previous picture. That's all she wrote..................cooling depends on the engine radiator.

There is a heat exchanger for the engine oil, but it's a completely different system. That particular heat exchanger sits directly behind the radiator fan, just ahead of the engine. Has 2 hard lines to carry hot oil, and 2 engine coolant lines that carry water........again........off the water pump.

These motors are probably 80%(I'm spit ballin' here, might be less) convection cooled. The water pump is not the primary source of water circulation. So, anything needing a positive flow of water will run off the water pump. Hence, the 2 heat exchangers run off the pump. At least that's my understanding of the system.

 

[farmersamm]

This might help understanding the system. They used to give the service departments excellent manuals. I'm not sure they do as well these days.

Anyways.........I gotta date with the machine tools this morning. Gotta bounce. I've got somewhat of a reprieve.........we're expecting heavy rain this weekend, so I can't run even if I was up and running. Gives a little time to get things in order.

 

[rrman61]

View attachment 81921

View attachment 81922

This might help understanding the system. They used to give the service departments excellent manuals. I'm not sure they do as well these days.

Anyways.........I gotta date with the machine tools this morning. Gotta bounce. I've got somewhat of a reprieve.........we're expecting heavy rain this weekend, so I can't run even if I was up and running. Gives a little time to get things in order.

Something to think about;remove the hydra power and convert it to direct only.we had 1-1650 and 3-1950’s all direct only(no hydra or 3 speed)

 

[farmersamm]

Your early post seems to indicate that heat/cooling may be an issue. I have a comparable tractor, 1650D w/ hydra-power. I'm at least 3rd owner. While doing routine checkup, maintenance etc I found cooler was severely blocked w/ crud. Ran garden hose thru it a while and cleaned good.. I've never had any issues w/ shifting etc. Cheap thing to check.

Hey........I was in the shop today, and I thought about what you said. I'm thinking we might be having a communication problem.

I call the thing a HEAT EXCHANGER, and don't think about it as anything else. I had a bad upbringing

Anyways.......when you started talking about a COOLER, I didn't put 2&2 together. I was thinking you were talking about something unrelated.

If you're referring to flushing the water jacket(on the heat exchanger), I think I understand you.

Now that I think about it, I can see where sediment might collect in the downward sloping part of the thing. Might even cut the efficiency of the oil carrying core MONDO significantly. Less surface area exposed to the actual water if the thing is blocked. I think I get ya

Can't hurt, and might be a problem I'm not seeing...................will do.

BTW........when I put an IR on it, I was seeing 195 on the body of the cooler/exchanger...........165ish on what I assume is the inbound water hose..........and about 180 on what is probably the outbound hose. So, you're definitely seeing a temperature gradient, but is it as efficient as it could be. One flush comin' up. Be stupid not to. Thanks.

On the subject of IR's. They're not totally accurate. Depends on the color of the surface you're measuring. Lighter the surface, less accurate. It's more of a comparative thing. I shot all temps on grease patches that were darker than the surrounding areas. So, I should be in the ballpark.

My shop is a "shop in a can". I work out of a shipping container...........which on a hot day down here, might reach close to 120*. The machine tools will start to run hot. I can hit the side of the headstock on the lathe with the IR, and get a cooler temp than when I hit the sight glass in the sump. All about the reflectivity of what you's aiming at. I believe there are tables that give temp differentials based on the material you're actually measuring. I think the baseline is black.

 

[farmersamm]

Rough blank for the tester base, centered, and marked for the pipe that has to be welded to it.

Scrounged some pipe. Not sure what it's made of..............took near on all day to cut it on the bandsaw. Some kinda high carbon steel.

Weldered her out. Not being a pipliner, or pressure welder.................I suck at anything round. Have to do it in short segments. Lotta starts. Being as it's mystery metal, figured 7018 was the most tolerant filler metal to use.

Toddled off to town to have a hose made. Was gonna pick up a tap on the way home, but the parts store only had an open package tap.........which appeared to have been bought, used, and returned. Got another one coming tomorrow. More windshield time I guess.

 

[GermantownGreen]

Good luck with your project. Great pics and sharing. GG Wes

 

[farmersamm]

The original drilled hole in the blank is what everything else will index from. I'll preserve this hole, as is, until the base is threaded. Part is centered, then checked for face runout.

Rather than reinventing the wheel, I'm just making it conform to the filter. These filters are common, in terms of diameter, on the tractor, and just about everything else I own.

Luckily, Wix publishes their specs. Otherwise this would be even more stressful. I don't like making scrap, and I always worry whether something will do what it's supposed to do.............as originally engineered. My version has to be as good as the engineered version, otherwise it's possible that I can do damage to the system.

This has been the greatest area of concern. Whether my flow rate will equal the filter as it came from the factory. (Missed my mark on one little hole.........don't tell, and I wont). Running the numbers............. The outflow diameter of the threaded hole will be approximately ..625(5/8). The eight .250 holes have an area of .392 square inches. The threaded hole will have an effective area of around .306ish. This is a rough estimate, taking into consideration of the diameter of the stand pipe that the thing threads onto. I'm being conservative, and allowing for a larger diameter stand pipe. In terms of diameters, my flow rate should be the same across all holes in the base.

Next, I need a plug guage.

 

[farmersamm]

When threading, I'll use a known source as a gauge..........but only as a rough indicator. Granted...........my gauge isn't gonna be to the high standards of a purchased gauge, but it'll be close enough. The filter is NOT used as a final fit for the thread......it just tells me I'm in the ballpark.

Machinery's calls out the pitch diameter for a 3/4-16 thread at .7079-.7029 . I'm good to go.

Machinery's calls out the major diameter at .7485-.7391 . Same same, I'm golden.

Nit picky........................You betcha. I need to stay in tolerance so's the doggone thing will fit any commercially made thread. This will go on multiple vehicles, none of which do I know the actual thread specs as machined. Assuming all other threads in the known world,conform to standards, my in-tolerance thread will fit them all. This goes beyond fitting a known nut to the thread you're turning..........that sort of stuff, while it works for the particular nut, may not work with another nut from a different batch. This problem is worse than ever, now that all of what we're seeing, is made on the other side of the planet. I've done the best I can do........let's hope some doood in a far far away land did the same.