Top link mounting hole?

[Fallon]

In this episode of reading the manual, I was checking out the table listing implements, soil conditions, Check chain tightness & a few other things. It was recommending different top link holes for different implements & soil conditions. Why is this? Better leverage on the implement? More adjustment range? Something to due with draft control (which My L3200 doesn't have unless you dig up obscure options).

I've got a quick hitch on & have just been leaving the top link in the middle hole. The only time the QH comes off is for the PTO post hole digger. I'm in the process of putting in a TnT system & was just planning on leaving it in the middle hole. Does the QD negate any of the need to use different top link holes? Or is it still a good idea, but never gets done because it's too much work?

 

[stuckmotor]

Wouldn't putting the top link of the post hole digger in the lowest hole raise the auger higher from the ground?

 

[Tx Jim]

Without the option of draft control the only thing about relocating center link attaching hole on tractor will do is change attached implement rear height depending on hole utilized.

Lower hole= higher lift height, higher hole= lower lift height

 

[dieselcrawler]

It's all about geometry. The top hole will cause the impliment to rise less in the rear as the lift arms go up, bottom will cause it to rise most as it goes from low lift larms to raised lift arms. I'm sure there are draft control issues if equiped but the everyday user doing chores will use the diffrent holes to their advantage as needed and like you likely settle on one they like. My 3005 has only one hole... but brush hogging, where I like to let the top link slack so the BH follows the banks, it would be nice to get more rise at the tail wheel in the lifted position. I would use the bottom hole if I had one.

 

[oosik]

Not to fear - I wondered about the three holes for the top link also. My OP manual says, select the proper set of holes by referring to the "hydraulic control unit use reference chart". This chart lists most of the "heavy contact" ground engagement implements. It goes on to say - (paraphrase) - if you want draft control - ex, mold board plow, disk plow, spike or springtooth harrow - then use the lowest hole because it is the most sensitive to implement operating conditions. If you do not want draft control then use the top hole. Now that's pretty plain. I do use the bottom hole when using my moldboard plow and do adjust the draft control also. Otherwise, I use the top hole for everything else. My tractor does have draft control and I do use it although the large rocks I'm almost continuously unearthing may screw up this setting. Also, if your tractor does not have draft control then I would use which ever hole best controls the vertical movement of your implement - no pun intended.

 

[newbury]

In this episode of reading the manual,

WHAT - reading the MANUAL??

Why not Google [top link draft control site:www.tractorbynet.com]

Anyways I think LD1 put it best:

Without draft control, the 3 holes are just to give you flexibility in how you want the implement to react when raising.

The uppermost hole will give the most lifting power, but less lift height at the tail of the implement. This hole also keeps the implement the most level through out the lift cycle (handy for a trailer-mover-hitch-thingy). It also puts the least about of stress on the top link and top link mount.

The bottom hole will give less lift force, but much more range of travel at the tail of the implement. It also puts the most stress on the TL. This hole is handy for things like a boom pole that you need alot of height but not much power, or for very un-even terrain with a longer implement like a blade or brush cutter, as it lifts the tailwheel higher. Also handy for loading those implements on a trailer with a steep ramp.

The middle hole is just that....middle of the road.

So whatever hole you use dont really matter to much, its just options to give you a choice in how you want things to react.

 

[murphy1244]

How would the top hole change how high the implement goes? I mean the top link does not limit the height, the position control and the lower links do.

 

[jones6780]

Murph, Its the geometry, if the tractor side dimensions and angles are the same as the implement side then the lift would be level. With a change on the tractor side the implement side will have a corresponding change.

 

[k0ua]

How would the top hole change how high the implement goes? I mean the top link does not limit the height, the position control and the lower links do.

There are two answers to that question:

1: trust me it does. or try it yourself. with the top link jack screw all the way in or your hydraulic link all the way in. put it in the bottom hole and hook on a rotary cutter or some other long implement where it will be the most noticeable and measure the tailwheel height then put it in the top hole and measure it. The bottom hole will raise the tailwheel higher.

2: It is geometry. The geometry is a parallelogram. the toplink is the top of the parallelogram, the lower links the bottom, the left side of the parallelogram is the fixed height of the measurement of the pins and the top link hole on the implement. the dynamic measurement of the right side of the parallelogram is the height measurement of the pins where the tractor end of the lower link arms fasten on to the tractor and the holes where the top link will fasten to the tractor. Your choice of top, middle or lower hole. If you choose the lower hole the right side of the parallelogram will be shorter and as you raise the lower link arms they rotate around the their fixed pins on the tractor, and since the top link jack screw is turned all the way in, the left side of the parallelogram will tilt more toward the tractor which will raise the tail wheel higher off of the ground. If you don't understand all of this, see answer 1 above

James K0UA

 

[Gordon Gould]

The different holes are for adjustments for heavy ground engagement impliments or heavy loads like loggs.
Other than that if there is no heavy ground engagement or heavy loads they are useful to adjust how and impliment lifts.

Heavy ground engagement: The important thing is to look at the angle of your top link. Draw an imaginary line along the top link towards your tractor rear axle. The force on the top link is along this line. The higher this line is where it crosses directly above the axle the more leverage the top link force has on the tractor to rotate it about the axle.
So - if you have a ripper on say or deep plow, that is liable to hook on a rock or something and stop what happens is the ripper tries to rotate forward when it stops deep in the ground. This makes the the ripper push forward on the tractor thru the top link along that imaginary line. The force will tend to push the front of the tractor down while the tires are trying to lift the front of the tractor up because it is stopped. If you are in the top hole the top link force pushing the front down is greater than if in the bottom hole. So the top hole is safer when you get the impliment caught.
Now - pick up the impliment so its weight is hanging in the 3pth. In this case the force on the top link is pulling and trying to pick the front of the tractor up. If you have on a disc or plow in wet ground and dirt is stuck to the impliment when you pick up the impliment can be very heavy. If you use the bottom hole for the top link with heavy loads above ground like disc sets or logs the heavy weight will be less likely to pick the front of the tractor up. It is a big trade off between impliment weight and what happens below ground when in use. Invented by Fergerson - look him up.

Another thing. If you use a top link hole that makes your top link parrellel to the lift arms then your impliment will not change its angle when it is lifted or lowered. A handy thing when going road work with a blade of some type. or a carry all you want to keep level.
The steeper the top link angle compared to the lift arms the more the impliment will rotate back as it is lifted, making it go higher. So if you have on a blade and want it to lift it high to pull dirt from the top of a pile use the bottom hole to make the top link angled up more.