Need help with mf 165 hydraulic issue

1972 MF 165 diesel
No multipower
6 speed total HI and LO

Tractor seems to lift 6' bush hog and finish mower OK.

Went to lift 6' heavy duty grader blade. It seems to lift it... maybe some chatter when it gets to top of lift. But when I disengage the clutch... there is a loud knocking seeming to be coming from tranny area, by gear shifters. Pretty rapid loud knock.

The story beforehand.... had the tractor for a month. Just been bushhogging. I used a boompole to lift grader blade off my trailer. It did lift it... but chattered. Then all of a sudden it dropped it... wouldn't lift it again. Hydraulic fluid looked good on dipstick reading.... not milky, just a few bubbles on dipstick. Someone told me to add hydraulic fluid any way. So I added 2 gallons. The boompole did try to lift then. So I unhooked it... and started mowing again. I hooked grader blade up tonight. It is now lifting the blade fully, maybe some chattering at top. But when its fully lifted in transport position... it starts knocking loud when you disengage clutch.

Any ideas?

Any problem with it being overfilled of fluid?

Before all of this happen.... I do believe I was hearing the knocking... but not as loud... while transporting the Bush hog. But seems to be really loud the heavier the transport load is.

Kind of sounds like it broke the clutch disk for the 3 point pump/pto. There is a cover plate under the tractor behind the engine that is held on with 4 bolts that is used to access the clutch so it can be adjusted. Take that plate off, and look around at the clutch, sometimes clutch parts will be laying on top the cover plate.

(quoted from post at 21:59:05 06/13/18) Kind of sounds like it broke the clutch disk for the 3 point pump/pto. There is a cover plate under the tractor behind the engine that is held on with 4 bolts that is used to access the clutch so it can be adjusted. Take that plate off, and look around at the clutch, sometimes clutch parts will be laying on top the cover plate.

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Talking about the clutch... I've read it's only supposed to travel 1/8 of an inch of free travel? I haven't measured it yet, but I think mine travels at least an inch or maybe 2 inches. Could this go along with what you stated above?

If the clutch pedal only has a 1/8" of free play (free travel) it would be pushing the clutch too much which is not good.

When I setup a clutch I like the pto clutch to be disengaged to where it has no more than 1 inch of travel until the clutch pedal bottoms out on the foot plate so it doesn't push the clutch in too far. Since you have 2 inches of free play/free travel (in the pedal I assume) before you feel pressure against the clutch pedal I don't think that would be a problem.

(quoted from post at 22:41:07 06/13/18) If the clutch pedal only has a 1/8" of free play (free travel) it would be pushing the clutch too much which is not good.

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So how much free travel do you want? I'm saying I think my clutch pedal has somewhere between 1" to 2" of free travel. But I just eyed balled pressing the clutch pedal downward til I felt resistance. Do you measure some other way or place?

(quoted from post at 22:48:06 06/13/18) So how much free travel do you want? I'm saying I think my clutch pedal has somewhere between 1" to 2" of free travel. But I just eyed balled pressing the clutch pedal downward til I felt resistance. Do you measure some other way or place?

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The free play after I adjust a clutch has about the same amount as your does. Like I said earlier I like the pto clutch to be disengaged when the pedal is about a inch from the foot plate so the clutch doesn't get pushed further down than needed. What ever the free play in the pedal from when the pedal is all the way up until when you feel resistance is however much it is.

At this point, if I'm over filled 2 gallons of hydraulic fluid... would that cause any issues using it? Or be causing the louder knocking?

It shouldn't but a input shaft seal could leak some out into the bell housing so I would drain the extra 2 gallons out.

(quoted from post at 09:00:45 06/14/18) It shouldn't but a input shaft seal could leak some out into the bell housing so I would drain the extra 2 gallons out.

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what happens if it gets into the bell housing?

The oil could get on the friction material on the clutch disks which is not good for the disks.

Hi, I would certainly agree with the possibility that the PTO plate lining is broken and a broken bit has moved to form
two layers of lining on one side of the plate. The pedal will feel reasonably normal but will not release as it is not
being lifted enough when the pedal is pressed to the bottom of the second stage.

DavidP, South Wales

(quoted from post at 14:44:35 06/15/18) Hi, I would certainly agree with the possibility that the PTO plate lining is broken and a broken bit has moved to form
two layers of lining on one side of the plate. The pedal will feel reasonably normal but will not release as it is not
being lifted enough when the pedal is pressed to the bottom of the second stage.

DavidP, South Wales

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Update:
I drained the excess fluid out. I can try to take a picture of the fluid. I originally said it wasn't milky...but maybe it is. The fluid that came out looked more like motor oil, had to make a double take to ensure I pulled the right plug. I noticed when some hit the ground, it separated into parts that were really dark fluid and really light fluid.

I played around more with the levers. It seems like I can only get the 3pt hitch to drop if I use the draft control lever. I should be able to drop it using the position control lever. I noticed on the position control lever.... once you start pushing it to the "down" position the lever meets alot of resistance...and as you pull it back up as well. As it gets closer to the "constant pumping" it is easier to move.

I could position the 'position control' lever slight down.... even though it didn't change the position of the 3pt hitch.... and it seemed to quit knocking "sometimes". When i'm in the transport position it knocks very loud...but I know i'm not in "constant pumping" it definitely increases to a rapid loud knock as I increase the throttle. At low throttle it doesn't seem to do it. It almost feels like there is a long rod banging around from gear shifts towards rear of tractor.

If anyone has any more ideas with the info above, I'm going to be by the tractor again this weekend. I'll try out what anybody suggests and I'm going to verify for sure when the knocking takes place.

1) worried about the consistency of the hydraulic fluid (similar to motor oil, separates into darker/clearer fluid)

2)position control lever meets resistance towards the 'down position'

3)I will verify for sure the knocking again... but definitely increases in sound and rapidness with increase in throttle... and when clutch is depressed to floor it won't knock. Definitely knocks louder with a 750lb grader blade raised vs a 7' finish mower.