oil pan removal

Duramax88 · Aug 17, 2019

Hello everyone. I have a Jinma 354 tractor and I am trying to remove my oil pan. I have looked and believe I found all the bolts holding the oil pan on even the 2 in the front but cant get the oil pan to drop. I would think that as heavy as it is that once you removed the bolts it would pretty drop down. To explain I went all around the top of the oil pan and removed all the bolts. I also removed the 2 bolts in front of the oil pan that screw into the side. My question is _ am I forgetting something? Thanks

Duramax88 · Aug 17, 2019

Got it off witch means I have more questions. According to the manuals I have there is supposed to be a oil pump and screen however there is only a oil weldment screen. I am looking for help. First let me say I am not a mechanic but do have some common sense. I am looking for the location of the oil pump and the screen. I also am curious as to what the purpose of the weldment screen is? I also see that it leads into a tunnel and comes up at the back of the oil pan and looks like it goes up into the engine. The whole reason for trying to find the oil pump and screen is to see if there is any blockage. I am not getting any oil pressure to speak of. If I remove the sending unit and start the motor it pumps out of the hole where the sending unit screws in real good but I hooked up a mechanical oil pressure gauge and get nothing. Not sure where to go from here. Any help would be appreciated. Thanks

Duramax88 · Aug 17, 2019

Ok back again, after further searching I believe I found out where the oil pump is located. It looks like it bolts to the engine block behind the harmonic balancer. If that is the case does the harmonic balancer and associated gear need to be removed in order to take the oil pump off? Also is there a check I can do to see if the oil pump is bad before going through the process of removing it? I was looking at the bottom of the block in the front below what I believe is the oil pump and on the bottom of the block where it looks like the oil drains into the oil pan is a orfice that is threaded. I assume there should be something screwed into it. Any ideas what that might be? Thanks

Bob Rooks · Aug 17, 2019

Duramax88 said:
Ok back again, after further searching I believe I found out where the oil pump is located. It looks like it bolts to the engine block behind the harmonic balancer.
That is correct. It drives off the crankshaft gear.

If that is the case does the harmonic balancer and associated gear need to be removed in order to take the oil pump off? Also is there a check I can do to see if the oil pump is bad before going through the process of removing it?
No and no.

I was looking at the bottom of the block in the front below what I believe is the oil pump and on the bottom of the block where it looks like the oil drains into the oil pan is a orfice that is threaded. I assume there should be something screwed into it. Any ideas what that might be?
Not sure, but it could be the oil pump pressure relief valve.

What has happened infrequently, is that the roll pin gets sheared. I don't precisely know what causes this but replacing with a spiral roll pin or using doubled up roll pins seems to work. That's number 10 in the pic.

Duramax88 · Aug 18, 2019

Hello Bob thank you very much for the reply. It helps a lot. If the roll pin is sheared would the oil pump still pick up the oil and push it through the engine? As I stated earlier in the post when I took off the sending unit and started the engine oil was coming out of where the sending unit screws in? It comes out good but when I screwed in the mechanical gauge there is not enough pressure to get a reading. I ensured that the mechanical gauge is working also. Would you happen to know a part number for the pressure relief valve or have a picture of it? On the oil filter housing there is a some type of pressure valve that is spring activated. Could that be the pressure valve for the oil pump or could there be one in the bottom of the block also? Lots of questions but I appreciate the help and I am learning as I go. One last question - Any idea why the CTOA website is down? Thanks again Bob for your help!!!

Bob Rooks · Aug 18, 2019

When there is no flow restriction (sending unit removed, free flow) there is a tight enough fit between the pump shaft and rotor to allow the rotor to turn and thus pump oil.

The Gerotor style oil pump should have a pre-set relief valve built in. If it has a broken or weak spring that would also indicate little or no oil pressure. This valve is not replaceable/repairable, you have to get a new pump assembly. That said, there is also a relief valve built into the oil filter head. The adjustment is under the large acorn nut. There are no valves that are built into the block.

As far as CTOA goes, I can only speculate, but it has gone through at least four iterations since it's inception back in '05. Hal Mandlemann the site owner, used to interact and actually was a contributor at one time but has ceased doing that some time ago. All I can say is that feces rolls uphill and those at the controls are ultimately responsible.

Duramax88 · Aug 18, 2019

Thanks Bob that answer a lot more of my questions. With that being said I am not going to take any chances. Tomorrow morning I am going to order a new one from affordable tractor and replace it. Do you have any tips on replacing the pump? Either getting it off or putting it back on or anything between that? You have been very helpful and I appreciate everything you have provided to me. Have a great Day and thanks again!!!!!

Bob Rooks · Aug 18, 2019

As an afterthought while you have it out, check the pickup tube (#25) closely for cracks, check and clean screen.

Duramax88 · Aug 18, 2019

Hello Bob, I looked at part # 25 and I don't have that. I attached pictures of what I have in my oil pan. I am not sure where the part you are referencing would be located. Thanks

sd455dan · Aug 18, 2019

Duramax88 said:
Hello Bob, I looked at part # 25 and I don't have that. I attached pictures of what I have in my oil pan. I am not sure where the part you are referencing would be located. Thanks

Your oil pick up and pan pics are different than the parts breakdown pic Bob posted

Do you have a picture looking at the front of the engine?

Maybe Bob is right and the pump mounts externally. and is accessible without front cover removal. on my Shanghai engine it is under the front cover and driven off of the crank gear.

If Jinma has it externally mounted It will sure make it easier to replace..

Bob Rooks · Aug 18, 2019

I was assuming (here we go again) that you have the TY395 series engine. What engine do you have?

Duramax88 · Aug 18, 2019

As far as I know I have the 395 engine. That's what I have been buying parts for. Forgot how to check. I will have to look it up to find out what to check.

Bob Rooks · Aug 18, 2019

Duramax88 said:
As far as I know I have the 395 engine. That's what I have been buying parts for. Forgot how to check. I will have to look it up to find out what to check.

Should be an ID plate in the left side of the engine under the intake manifold. Also a diamond with JD inside cast on to the block.

Duramax88 · Aug 18, 2019

Looked at the engine and found the JD stamp behind the injection pump. Under the manifold I found numbers stamped into the block but no tag (engine has been rebuilt with new block installed). Numbers look to read - 20111008.

Duramax88 · Aug 18, 2019

I can get a pic of the front of the motor but climbing under the tractor it sure looks like the oil pump is mounted there.

Texan4Life · Aug 19, 2019

Maybe I'm missing something but from the pictures it doesn't look like the pickup tube/screen goes anywhere or is connected to anything. What about a picture looking up into the engine from underneath? thanks for the pics so far... hopefully we can all put our heads together and get this figured out.

Duramax88 · Aug 19, 2019

Hello Texan4Life, I have attached some more pics of the oil pan. If you look at them you can see what looks like a tunnel. The screen has a hole back close to where it goes into the pan. From what I understand the oil gets sucked in through the screen and goes through the tunnel and up into the hole where you see the screw driver sticking in and goes into the block. I believe the hole in the block leads to the oil pump. I will get a pic of the bottom of the block and attach it later. Thanks for the help.

Bob Rooks · Aug 19, 2019

Behind that bolted cover I believe lies a check valve, which would keep the oil pump from losing it's prime when the engine isn't running. Not familiar with this particular setup, but You should still be able to remove the oil pump without removing any crankshaft components. Why don't you pop that cover and see what's in there before you go any further. That could be the culprit.

Here is the oil flow path.

Duramax88 · Aug 19, 2019

Hello all I was asked to show pics of the bottom of the engine so I have. I also added some others also - one is of the screen removed and showing the hole where it lets the oil travel into the tunnel and up to the engine, another one is of the hole into the bottom of the block and the other one is of the front of the block on the bottom of what I believe is the oil pump. Bob no check valve in the screen piece just a hole for oil passage. What's next? By the way thanks everyone for the help so far.