John Deere 3140 Hissing Noise Inside Rockshaft Housing - Normal?

[bigblock78]

Hello Everyone,

When I take off the hydraulic oil fill cap and listen inside, I hear a hissing noise as if oil is spraying somewhere. With the pto on or off or the 3pt arms up or down the sound doesn't really seem to change. Is this normal?

I ask because the 3pt arms would lower real quick on their own before so I redid the rockshaft seals. I thought that would take care of the hissing. While it did correct the leak down issue, the noise is still the same.

I have a 2120 and I don't hear that same hissing noise which is what has me concerned. My 2120 doesn't have a hi-lo leaver though while the 3140 does in case that is the difference.


BTW, my username used to be bigblock76, but the site wouldn't send me my password reset email. Ugh!

 

[Tx Jim]

Hissing sound coming from inside RS housing indicates leaking seals on RS control valves. Repair requires removal/disassembly of RS valve housing from RS housing which isn't a difficult job. Internal hyd leaks can cause hyd oil to get hot.

 

[buickanddeere]

Given the age of the seals it's likely they have hardened and cracked . This would be a good opportunity to check for disk brake wear and to toss a couple of powerful magnets in the bottom of the transmission sump.

 

[bigblock78]

Thanks for the responses. I did redo all the spool valve seals with a seal kit, also ordered new spools and seats (both of them). I went inside with a inspection camera this weekend. Fired up the tractor, What I could see is the the gears wizzing the oil and whisking it upwards. It took awhile to make sure I could see what I was looking at if the oil was being thrown up from the bottom and falling back down or if in fact it was coming from the spools. I think that has to be what it is. Maybe there is too much oil in it. Its at the full line on the dipstick when its running. But maybe it needs to be at the full line when its off? If that's the case it has to much oil in it?

 

[buickanddeere]

There are low pressure lines in the transmission that route oil for lubrication, operation of Pto and/or high low clutch pack and to supply the front pump.
On occasion one or more of those lines will crack and leak oil back into the sump. There are updated lines and some mechanics braze the new lines together instead of the push together connection.

 

[Tx Jim]

Its at the full line on the dipstick when its running. But maybe it needs to be at the full line when its off? If that's the case it has to much oil in it?

Smaller Mannheim built tractors require hyd oil to be checked with engine at idle speed but I'm not sure about the larger models with the 6 cyl engines. Another thought is have you checked for proper clearance on RS valves operation mechanism?

 

[bigblock78]

Is there a risk of backing off the tapered screw to the point where it falls off?

 

[Tx Jim]

I suppose that could happen but that would mean you did a lot more turning of adjusting screw than required to give valves sufficient clearance.

 

[bigblock78]

Hi Tx Jim, Well fixed the 2120. Went to do the same with the 3140 in case the valve clearance was causing this noise at all. I didn't even get to adjusting that screw that sets the clearance against the spool valves... I moved the load control lever to the top (Max I think it says). Pulled the plug off, started the tractor and I heard a pop and the 3pt arms starting rising up and oil started pouring out the plug hole even though I had the 3pt lever all the way down. I shut the engine off pretty fast but no matter what I did with the 3pt lever, the arms wouldn't go down. The down rate adjuster screw was backed all the way off. I started the tractor again and again they started to rise but oil pouring all out the side. Shut it off again. Now the arms wouldn't drop and I can't move the load control lever back down at all, it's stuck.

I got my inspection scope camera out, put it in the plug hole on the side of the housing and I could see that the linkages has 1 spooler valve all the way pushed in, and the other valve has 1/4 clearance. I was able to get a screw driver and push down on the spooler to lower the linkages and take the pressure off but the load control lever is still stuck. I've even applied pressure with a crowbar and it's locked in place. I feel as something has gone over center inside and that's why I can't get it back, however that is something I didn't not fool around with when I took it all apart. I never changed any linkage settings other than that tapered screw.

Any ideas how I can get this resolved without taking the rockshaft cover back off? If I do, what do I need to adjust so that this doesn't happen again! What a project this has become.

 

[Tx Jim]

Is the 3140 OS or cab style? I've never experienced what you describe happening. I think simplest thing to do is remove RS housing for an inspection if your tractor has no cab. My guess is RS control linkage is not contacting follower(key 16) correctly.