Toplink What are the different positions for top link?
- Thread starter Bessemer
- Start date
N80
Super Member
I'm not sure. My manual shows the same kind of info, which hole for which type of implement. But there is no explanation.
Someone here on TBN said that the top link should be as close to parallel with the lower lift arms as possible. I don't know if or why that is true either, but it sounds good.
Someone here on TBN said that the top link should be as close to parallel with the lower lift arms as possible. I don't know if or why that is true either, but it sounds good.
NFA Fun
Member
The manual on my JD says they are for different weights of attachments. The lighter one such as a rake would go on the bottom, and the heavier plows and such would go up top.
greg_g
Super Member
- Joined
- Dec 18, 2003
- Messages
- 6,086
- Location
- Western Kentucky
- Tractor
- JD3720 Cab, 300X loader with 4-in-1 bucket
There are two reasons for the different holes if your tractor is equipped with draft control. If not, there is only one reason. Let me know if you don't have draft, it will save me some typingBessemer said:
//greg//
greg_g
Super Member
- Joined
- Dec 18, 2003
- Messages
- 6,086
- Location
- Western Kentucky
- Tractor
- JD3720 Cab, 300X loader with 4-in-1 bucket
OK. Then what you read in the manual doesn't apply to your tractor, leaving only one reason for the multiple holes. Not all implements have the same distance between their lower lift pins and the toplink hole. The most advantageous three point hitch working geometry is obtained when the toplink is as close to parallel as possible with the lower lift arms.Bessemer said:
Pin the toplink in the center hole, connect the implement to the tractor. Use the tractor hydraulics to position the implement at its normal working height. Stand off to the side. If the toplink is approximately parallel with the lower lift arms, you're good to go. If not, move the tractor end of the toplink up or down as needed to get as close to parallel as possible with the lower lift arms.
//greg//
mwb
Platinum Member
NFA Fun said:
This is not exactly correct depending on how your top link connects to the draft. For heavy draft loads (plows) you would connect to the hole that gives the least mechanical advantage (closest hole to the draft sensing shaft). Light draft equipment (rake) would go to the furthest hole to give the lighter load more mechanical advantage over the draft sensor.
On both my Ford 2000 and my new Montana 3940HST it is the top hole for light weight equipment, bottom for plows. Other models (like the JD above) obviously have a different design.
Cheers,
Mike
StrangeRanger
Gold Member
Similar to mwb, as I understand the manual for my L3400 HST w/out draft control you use the lower holes for heavier/more drag resistance implements like plows and box blades. The upper holes are used for lighter/less resistance items like rakes.
At least that's how I understand it.
At least that's how I understand it.
The different positions also are used to produce optimum operating geometry for the implement. This means setting a rototiller vertical when its in the ground, a post hole digger to be vertical as possible (when its in the hole), and even to prevent your bush hog from hitting the tires when its full up. What I do is to set the equipment up in operating position and then pick the link hole and top link length to get the job done. The true description of this setup is a four-bar linkage for which you get to adjust the angle and angular trace of the front of the implement. This keeps the driveline happy too, by minimizing shaft length variation and u-joint angle differences. A pto driveline is intended to run as a constant angular velocity connection, but won't if the front and rear angles are different. This condition will beat up a driveline (both tractor and implement) if its running under a lot of power.