G'day ArcherXC.
I have Replied to this question in a previous post as to why the Massey hydraulic system KNOCKS when the three point hitch is raised to the Transport position.
Suggesting that this is normal is not so and to operate a tractor in this condition will eventually destroy The releif valve and eventually lead to premature failure of the pump not to mention the Loss of engine power due to the Parasitic effect of the hydraulic pump being constantly under load.
The knocking is an indication that the hydraulics are either out of adjustment or are being used incorrectly.
Let me say firstly that comparing the English tractor to the U.S manufactured tractors they differ in the hydraulic quadrant layout which sometimes leads to confusion among our learned members.
Lets talk about the U.S system that you have.
Example you are using a plow ,rotary hoe or any other Draft controlled Implement, firstly the position control lever should be set in the transport position and left there,More about that in a moment, The draft or Depth of implement engagement is controlled in some respects automatically by the tractor hydraulic system a system which communicates Mechanically via the top link ,the top link has an internal sensing rod which via the ferguson patented draft system sends a mechanical signal to the Hydraulic control Valve raising and lowering the lift linkage ,to maintain the Preset Draft .
The Draft control lever will respond as intended only if soil conditions are CONSISTENT If for example you are plowing an area where the soil condition varies ,say where there is a hollow and the soil is more penetrable the Draft lever may have to be raised slightly to maintain a constant Depth and consequently Lowered again as condition change This is where the adjustable Draft Neutral Reference stop
is used ,The reference stop on the picture is located at the lower end of the Draft quadrant.
Position Control.The position control Generally is used as it,s name suggests To Infinitly Control the Height of the Three point Linkage,Example Using a carryall ,Brush hog ,etc If the linkage is set to transport position The implement will Lift and Stop at a measured distance from the Fully raised position and it will stay there ,if the lever is moved down the quadrant the hydraulics will respond accordingly,lowering and holding at that position The linkage will not DRIFT up or down.
The constant Pumping Position will provide a constant supply of oil from the three external tapping points or if fitted a selector valve, This oil supply can be used to raise a tipping trailer or drive other hydraulically operated implements,Note the pressure will be at relief valve pressure,Depending on the valve fitted 2250 ..2500 P.S.I.
The Response lever ,right hand side of the transmission next to the oil level dipstick will when used will control the RATE OF DROP of the three point hitch only ,example when the tractor has a heavy piece of equipment and you want to lower it slowly ,move the lever towards Slow untill you have the rate of drop that you are happy with.
The reason that if when using the position OR Draft control levers The hydraulic system internal and to a point the external adjustments are carried out with the both levers set in a known position and if they are not used as descirbed will not operate as intended
The Knocking Pump.
The hydraulc pump is unusual in the fact that it is a positive displacement piston pump (Scotch Yoke)the pistons (4off) being driven via two bronze/brass Camblocks which in turn are driven by a splined through shaft with cam lobes this shaft at the rear provides drive for the Power takeoff via a sliding gear.
When the linkage is raised and when it reaches the upper limit of travel if the sector adjustment is not set correctly the hydraulic system will hover around the Releif valve dump Pressure and the fact that the pump is ,one a piston pump two is gear driven ,and last but not least IS driven via a gear train with three splined connections with normal running clearance this lot causes not only the pump to RATTLE OR KNOCK but the shafts to contribute to the Racket.
The relief valve when it LIFTS will initially slow the engine down and you will hear a hiss ,IT WILL NOT RATTLE as said the Knock comes from the convoluted Mechanical drive to the pump.
To fix the problem.
Set the draft lever to the fully raised position and with a weight on the three point linkage raise the POSITION CONTROL lever all the way up , mark the lift cover where the lift arms pivot ,mark a line across both the lift arm and the cover then lower slowly lower till the rattle stops ,then lower another 1/8 "inch with reference to the Photograph there is an adjustable stop with two retaining bolts ,loosen these of and adjust so that when the linkage is raised to theTRANSPORT position the lift lever will contact the upper limit stop BEFORE it reaches the CONSTANT PUMPING POSITION.
No more rattle.
Thats all for now
Regards.
Hutch
