# IH 656 Hydrostat/Hydraulics died



## IHHydrostat656

I am new to tractors/hydraulics with my recent purchase of a gas IH 656 with hydrostatic drive, and front loader. But, I am somewhat of a backyard mechanic. I am having big troubles with my IH 656 hydraulics/hydrostatic drive which just stopped working. All hydraulics, including the steering and the PTO. 

When I purchased the tractor a few months back, it ran and all the hydraulics worked (with some bubbles and a light milky color in the hydro fluid), but it was blowing radiator fluid into the oil. I diagnosed this as a blown head basket, and, over a number of months, finally got it replaced. 

As I just got it running again, and was adjusting it, and trying to run it a few minutes to check the true level of the hydraulic fluid, it started making a whining noise and it didn't sound good. That noise continued for a minute or two so I could try to check the fluid level. It appeared to be fine, was a golden color, with no bubbles and wasn't milky. I noticed that the fluid level didn't change from when it was off to after it was run for more than three minutes at higher rpm.

Then, I tried to use the hydraulics, and nothing worked. Again, before I pulled the head, they worked - the loader, drove forward and backward, steering and the PTO worked. Now, none of them works. I called the Case IH dealer and he said that before I do anything, I should change the hydraulic filters. He asked me what the fluid looked like and I told him. Now, not having replaced any of the fluid after changing the hydraulic filters, the fluid is golden in color, clear, with no bubbles. But, nothing works. I suspect that the hydraulic pump isn't working because the hydraulic fluid level is the same when not running than after it is running for a few minutes at 1800 rpm (a little over the top full mark).

The IH dealer thinks it may be a bad plate (like a fly wheel?) which comes off the motor which drives everything - broken/shattered or something because nothing is working - hydrostatic drive, front bucket, steering, or PTO. Is there anyway I can check for this, or check the hydraulic pumps, or whatever else may be wrong? Any help would be appreciated - this is my first tractor, and everything hydraulic is especially new to me.

Thanks!


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## cyrush

Hi, sounds like dealer says "a flex plate failure" this is the drive plate bolted to the flywheel into which the transmission shaft couples to drive the tranny , pto etc. 

Dont know your model as they were not sold in Europe, but is there a small inspection plate underneath the bell housing you could remove to inspect??


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## IHHydrostat656

Thanks, Cyrush, for responding. I am familiar with what the dealer thought it might be, and will check again to see if there is a plate that I can open to look inside to see if the flex plate is in good shape or not. He also thought that I might be able to remove the hydraulic pump so I could see if the drive was moving or not to power the hydraulic pump. So far, all I can see on the housing are bolts that I am guessing access the hydraulic fluid area and if I remove them will dump out the 20 gallons of hydraulic fluid this thing holds. I'll look further to see if there are any higher that might give me a peep hole to look inside.

What I was hoping was that some members on this forum would give me other ideas of what it might be, or help pinpoint what it has to be or what it can't be given my description besides what the dealer/owner said what it might be given my description over the phone to him. 

Thanks!


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## IHHydrostat656

*Inspection plate query*

Cyrush, I hunted around some more and saw a plate up higher on the bell housing that I felt comfortable removing. It was what I thought it was - a plate through which you could see the flywheel and mark it so you can time the engine. All I can see through that 1" by 5" hole was the front side of the fly wheel.

Underneath the bell housing - if you could call it that because it is one big piece of housing which houses lots of other things - is a large plate, with a smaller plate attached to that, along with a drain plug, etc. I don't know if I can open up the smaller plate and see things from there. 

I tried things again on the tractor, trying the bleeding procedure outlined in the Operator's Manual, and did so with the front bucket, and PTO, and nothing happened. Nothing works. 

Could I have done something to the hydraulics to ruin them after I replaced the head gasket and got the tractor back up and running enginewise? Again, the hydraulic/hydrostatic fluid was a little higher than the full mark on the dipstick when shut off, and after running it for 3-5 minutes (engine shut off).

Thanks!


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## IHHydrostat656

*Advice still requested*

I forgot to mention that all I could see through the flywheel hole was the flywheel, and it appeared to be fine. I inspected it with the engine off and while running.

I believe I mentioned earlier that the fluid level in the hydraulics remained the same whether it was cold and off, or running and warmed up. The fluid level didn't change.

Thoughts? Ideas? What else can I check or do I need to get it hauled to the tractor shop for major repairs?

Thanks!


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## cyrush

Above those plates is the hydro unit and one hell of a lot of oil !!!!

On the inspection hole you discovered, can u get a mirror through to see the rear face if flywheel and drive shaft ) or do you know someone who might have one of these portable endoscopes that you can poke in awkward holes to see whats going on ?? (Building surveyor etc??)

Failing that i think you must bite the bullet and split the tractor @ the engine / bell housing joint. 

AS there is no pto drive the internal transfer pumps wont be working hence no change in fluid levels. 

I have looked in service manual for 966----Hydro 186 but it does not show any easy access to that area.


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## IHHydrostat656

*More holes to look into?*

Well, today I drove around and talked to a number of tractor mechanics and tractor shop owners to hear what they had to advise. All seemed to point to splitting the tractor and fixing what's wrong - the flex plate or perhaps the drive shaft in there.

The IH dealer said that he thinks there is a plug near the starter motor which I could remove and peek into there. I also thought I might remove the starter motor and see if I could see things through that larger hole which would be right there on the back side of the flywheel.

Perhaps this is all an exercise for my satisfaction that I really need to break the tractor apart - everything seems to point to separating it and replacing the flex plate or shaft.

Thanks for your ideas, Cyrush. I'll let you know what else I find out.

Take care from Amerika!


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## cyrush

What did you eventually find as cause of failure.


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## IHHydrostat656

*IH Hydrostat 656 problem solved*

Well, since I didn't have the facilities (doing this out in the "field" with no garage), I paid to have my tractor towed to the shop. We figured it needed to be split to at least replace the flex plate. Sure enough, the flex plate was bad as well as the input shaft to the tranny. All in all, total cost $2,000. About $80 for the flex plate and $650 for the input shaft. Rest was labor and towing. 

Oh, and did I mention, my tractor must have been the last tractor on the list, as well as put aside whenever anything else came in the door. It took over 4 months to get it back. Guess us little podunks need to expect to be last on the list in "farming country".

Everyone, thanks for your help! Sorry it took so long to get back to y'all. But, it took forever to get the tractor back, and I'm getting more forgetful in my older years (52).

Take care!


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## cyrush

Glad to hear you eventually got it back ??? Best of luck !!


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## IHhydroman

Does anyone know why a 656 diesel Hydro transmission would fill all the way to the top with Hy-Trans oil to the point where it is seeping out of the top cover of the transmission, I have a feeling it is because I don't have my oil cooler lines routed right but that is a guess, I am restoring this tractor from the ground up , tractor finally moves forward and backwards after replacing charge pump and installing a new hydraulic pump and the side plate cover, any info with be much appreciated.


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## rockwood84

when the oil gets milky the moisture will stop up the hydraulic filter and steering,brakes and ta will
not work.the cover you took off have the steering pump on the backside of it. the pto shaft drives this pump on the backside of the mcv plate. on the mcv plate there are two valves that have to be adjusted to spec. on the routing of the cooler lines you need for the cooler to be in route of oil flow from pump to return to the oil resevior


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