# ooops, I removed the hydro gear check valve



## Wanabe (Nov 5, 2020)

I recently bought a low hours Craftsman 917.273022, 20hp Kohler. Ran great for a couple weeks. I heard the transaxle oil needs to be changed occasionally so I changed the filter and put in about 100oz of 20w50. When looking for a place to put oil in the trans, I mistakenly removed a check valve bolt at the back of the case. It has what looks like a shaft extending from the middle with a spring. Realizing that won't work I looked inside to verify things were ok (?). A conical piece with a flat base inside had fallen over against the side of the hole so I used a small screwdriver to stand it back up but upon reinspection, it looked as if it was gone. I assumed it was not as visible flush with the sides of the hole so I reinserted the bolt/ pin/ spring combo and snugged it tight. I Added oil through the vent plug hole. I reviewed the purge process, have done it many times but only get reverse motion now. Occasionally a slight forward under the no load condition, wheels off the ground. Did I screw up the check valve? Could that conical piece have fallen inside? Is it normally so difficult to purge with 20w50? Thanks in advance for any help.


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## BigT (Sep 15, 2014)

Hello Wanabe, welcome to the tractor forum.

You must confirm (carefully) that the conical piece is still there. If it happened to fall down into the housing, you will get no pressure, as it is basically an open valve.


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## Wanabe (Nov 5, 2020)

Are you familiar with the little Hydro Gear transaxles? If it did gall down in there, what is the easiest way to get it out? Im thinking either disassembly or turn it upside down and rattle the piece back out the check valve hole but the area around the inside of the hole is so small i dont think it will get back through there via gravity. I may give that a try. If no luck I'll have to find out which side cover it could have ended up in i suppose.


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## BigT (Sep 15, 2014)

Here's a U-Tube video covering disassembly:

google.com/search?q=hydro+gear+transaxle+disassembly&rlz=1C1CHBD_enUS923US923&oq=&aqs=chrome.0.69i59i450l8.1364212367j0j1&sourceid=chrome&ie=UTF-8


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## Wanabe (Nov 5, 2020)

Thanks BigT. It is nice having some experience to draw from. I learned to drive on an old tractor very similar to the one in you profile pic. I think I was 14. Thanks again for the info and the video reference.


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## Wanabe (Nov 5, 2020)

BigT said:


> Hello Wanabe, welcome to the tractor forum.
> 
> You must confirm (carefully) that the conical piece is still there. If it happened to fall down into the housing, you will get no pressure, as it is basically an open valve.


Hey BigT, You sound like you are familiar with the Hydro Gear Trans? I Drained the oil out today so I could see in there and confirm the conical piece was still there. It looks like that is it, in the picture, but your comment made me nervous about trying to take it out although I can see no holes big enough for it to go anywhere. What do you think? Is the conical piece in there? If so, why doesnt it fall in during use? This is my first rodeo with a hydrostatic trans so I just don't know what to expect. Thanks for the input.


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