top link 3pt position

[mf40inme]

I have a two part question, was wondering if I could get help on. I have an mf40 which i use for lots of loader work, and seasonal bushhogging and logging. I have always had trouble with my 3pth hitch since i have got it (the tractor was pretty much a derelict when I got it, the 3pt is last on the list for overhauling) Many thanks to those that have helped me over the last years, esepecially David P, Thank you. David turned me on to the top link/spring adjustments as a possible source. With my two little kids I have had trouble finding the time to actually tear into it.

Yesterday I was watching the tractor lift my bushhog, the arms shoot up, right till i see the top link get involved and pull out, changing the internal draft valves. I moved the top link to the lowest hole (farthest from the spring (mine has three mounts) low and behold, this made a vast difference. One question is, what is the intention for the 3 top link holes? Heavier attachments mount lower, less mechanical advantage on spring?

2) When the arms are all the way up, pretty loud rattles coming from in there around the pump area. I know that this is most likely the safety relief valve, or the poppet valves (am I right? now i am not so sure) My extremely long winded question is: do others hear some clattering from their pumps, am I going to damage something running it like this?

My apologies for this epically long winded post. Thanks to all.

 

[DavidP,South Wales]

Hello,
No problem with a long question. I and I'm sure that most of the readers welcome as much information on a problem as possible.
Top link position? There are quite a few reasons for more than one hole. Some tractors have two positions andgenerally the larger ones have three.
Choosing which position should be dependant on the implement. Generally this adjustment is for soil engaging implements and ploughs in particular. The following should be taken as an MF guide.
Top hole; A frames 560mm, 22" and above,
Middle hole; (if present) 460-560mm,
18-22"
Bottom hole; Less then 460mm 18"

Using a higher than normal hitch point increases the sensitivity of the hydraulic system and provides more weight for penetration. It also reduces ground clearance and can give uneven depth control.
Using in a lower position can cause the opposite effects eg looses sensitivity in depth control and make the transport position unnecessarily high.

Rattle; The first thing to check without any implement attached is that the linkage remains free when it is fully raised. Raise the linkage fully. It should be possible to lift it 1 to 1 1/2 inches further. Frequently an operator trying to gain a little extra lift will move the quadrant lever stop. This results in the linkage being on the point of jamming internally and the relief valve blowing, with the attendant risk of cylinder fracture. If the linkage is tight adjust the stop at the earliest opportunity.
This is a Ferguson/MF phenomenon. Nearly all older tractors will do it. My belief is that the pump under extreme pressure rattles sideways on its mounting dowels. There are probably at least probably 75% of other tractors 'rattling' around the world. There appears to be no danger in leaving 'well alone' however if the sound should increase or happen more regularly then it would be advisable to investigate.

Cheers

DavidP,South Wales

 

[Joe Ferguson]

Right-on David

We have MF tractors 35, 135, 50, 65, 165 for years
some have "Pressure control system". When new the position control at the maximum heigh position did not cause problems the arms stopped at upper position with no noise or bent effect. With the time and wear all our tractors have the position control stopper adjusted to avoid the arms to go too high and cause pump rattle/releif valve whining.

My 2¢

Joe Ferguson