8N 3PT not raising high enough?

[BossofBBQ]

Hey Folks,
I'm back again with (I hope) a simpler question than last time...
I don't think my 8N's 3 point is raising high enough. Measured at the link balls (at the very end of the lift arms) , it only raises to 25 inches. I can manually lift the entire 3pt mechanism for another 7 or so inches above that. If I lower the hitch all the way down, the link balls drop to only 4 inches above the ground. The only thing stopping them from going lower is the leveling box hitting the axle casting.

The hydraulics seem strong. It lifted my 6' Ford disc fine, but couldn't get it fully off the ground because that would mean lifting past the 25" mark.

Is there a way to adjust the hydraulic travel/range of motion?

 

[RayIN]

That kinda sounds like the relief/overpressure valve is bad on the hyd pump.

 

[Roadworthy]

See if there's a stop on the lever that operates the three point. Many tractors have them to set upper and lower limits on the three point. I use mine to limit the lowering point of my mower so it doesn't drag.

 

[EdGooding]

Hey Folks,
I'm back again with (I hope) a simpler question than last time...
I don't think my 8N's 3 point is raising high enough. Measured at the link balls (at the very end of the lift arms) , it only raises to 25 inches. I can manually lift the entire 3pt mechanism for another 7 or so inches above that. If I lower the hitch all the way down, the link balls drop to only 4 inches above the ground. The only thing stopping them from going lower is the leveling box hitting the axle casting.

The hydraulics seem strong. It lifted my 6' Ford disc fine, but couldn't get it fully off the ground because that would mean lifting past the 25" mark.

Is there a way to adjust the hydraulic travel/range of motion?

Your range of motion should be closer to 8" at the lowest and 33-34" at the highest. This assumes you have 28" rear wheels.

You may be looking at an overhaul of your top cover. Do you have any manuals?

 

[John0829]

Ed gave you the proper measurements, more likely than not someone put the lift arms back on it the wrong position when doing an R&R of the top cover. As for the free travel at the top of the lift, you will have some due to how the hydraulic cylinder is connected to the lift arms using the dog bone link.

 

[BossofBBQ]

Ed- my tractor has the 28" wheels, and I just recently obtained all the manuals: I&T FO4 service manual, Owners manual, and a master parts catalog/assembly manual.

I was out fiddling around with my middle buster/potato plow today, and made an interesting discovery: the 3pt won't raise at all when in "draft control" mode. When this happens, the lever under the seat is fully horizontal. But, if I continue to apply moderate downward pressure to it with my hand, my 3pt will raise to a full 34" and function correctly. When I stop manually holding the "draft control" lever down, I lose all hydraulic power. The lever is still horizontal at this time. If I switch the lever vertical (Position control), the arms only raise 25" above the ground.

I am running fresh TSC Traveller Brand UTF and the level is right up to the "full" mark on the dipstick.
Roadworthy- my tractor does not have a nifty stop on the adjuster lever, so there's nothing to restrict movement there.

I know these problems are difficult to diagnose online, but I couldn't seem to find any symptoms that match mine in the manuals. Something is obviously worn/broken internally, but how would I go about pinpointing the issue?

 

[EdGooding]

Ed- my tractor has the 28" wheels, and I just recently obtained all the manuals: I&T FO4 service manual, Owners manual, and a master parts catalog/assembly manual.

I was out fiddling around with my middle buster/potato plow today, and made an interesting discovery: the 3pt won't raise at all when in "draft control" mode. When this happens, the lever under the seat is fully horizontal. But, if I continue to apply moderate downward pressure to it with my hand, my 3pt will raise to a full 34" and function correctly. When I stop manually holding the "draft control" lever down, I lose all hydraulic power. The lever is still horizontal at this time. If I switch the lever vertical (Position control), the arms only raise 25" above the ground.

I am running fresh TSC Traveller Brand UTF and the level is right up to the "full" mark on the dipstick.
Roadworthy- my tractor does not have a nifty stop on the adjuster lever, so there's nothing to restrict movement there.

I know these problems are difficult to diagnose online, but I couldn't seem to find any symptoms that match mine in the manuals. Something is obviously worn/broken internally, but how would I go about pinpointing the issue?

I think you are headed towards removing your top cover behind the seat and going through it to check for worn parts and make the right adjustments. I'll be interested to see if John in KY agrees. If he does, then the FO4 gives the procedure. I can also send you supplementary info from Ford Tractor that gives more details on the procedure. The FO4 kinda assumes you know how to do the tasks, so it just tells you what to do. I have a copy of the Ford Tractor 8N Mechanic Training Manual, and it gives more details on how to do the steps. Holler at me (that's Virginia and Kentucky talk ) if you want it.

There are some good YouTube videos on this process. This is a good one:

Rachel knows her stuff.

You can even buy a tool to make the adjustments easier to get it right the first time: LG500-LG500 Years:1939-52 Lift Jig

 

[John0829]

I am 100% with Ed on this, sounds like you need to do an R&R on the linkages. It sounds like someone may have, at some point, used the wrong hole on the top link rocker causing it to bend the linkages inside the cover. The top hole is for implements needing a "light" draft, think cultivator, where the bottom hole is for heavy draft implements, think plow. Most the owners of the 8N tractors today do not know this and slap the top link in the top hole because, well, it's handier/easier to get at.

At the very least I would expect the cam follower pin to be worn out and possibly some wear on the cam as well since they never get any lubrication in spite of being in a housing full of oil.

So it is worth popping the top for a look see.