8N Lift Problem

[RICHMONDRON]

Hi. I bought an 8N a few weeks ago for bush hogging. The lift leaks down two minutes or so after I disengage the PTO and I know enough to pull the side cover, look for leaks, and probably replace the piston and rings in the lift cylinder, just haven't done it yet. The problem I have has to do with the lack of position control there is with the bush hog. It's a five foot bush hog so it shouldn't be too heavy for the tractor, but I can't get the height of the bush hog stabilly adjusted regardless of the position of the draft control lever (up or down). With the lift lever a tthe bottom of the quardrant, the bush hog is all the way down on the ground with the front of the sides digging in to the dirt. Moving the lift lever up in the quadrant does nothing untill I got about two inches from the top and then within the space of about one inch of travel in the quadrant, the bush hog comes all the way up. Moving the lift lever down a tiny bit results in downward motion of the bush hog, but stopping where I want it only lasts a few minutes and then its all the way up or dragging the ground again. I'm wondering if rebuilding the cylinder, if that is indeed what I need to do, will take care of that as well, or if there is something else I should be looking at as well.

Thoughts?

 

[HCooke]

When you replace the piston/rings, check the condition of the cam follower pin and cam. Then adjust the internal linkage per the FO4 manual or use Zane's jig.
Zane Sherman web page

 

[JMOR]

As HCooke said, it is very likely that the cam follower pin is worn away (not lubricated metal to metal) thus ruining your position sensing. The cam moves as the lift goes up & down & the cam follower pins rides on the cam, thus sensing lift position & commanding pump to provide output or dump fluid as required to maintain a constant position.

 

[grhouse]

Here is a picture that someone else uploaded (I cannot take credit) of the cam follower pin so you"ll know exactly where it is when you take the cover off. Gene

 

[RICHMONDRON]

Good stuff gentlemen! I'll get into it this weekend to see what things look like and get back with end results.

Thanks for your help!

 

[elmersooner]

you could do a temporary fix and attach chains-kinda like what 9n owners have been doing for years, but it should be the pin as described, if you have a helper it makes the job alot easier.

 

[KL-VA]

For a cutter I completely gave up on using the hydraulics for anything but lifting the beast for transport. Even with the lift working perfectly, it was far too common for something to hit the lever and change the height.

Get a set of limit chains. Limit Chains connect between the top link at the tractor and the lower links at the implement. Once the chains are set, when you drop the touch control lever, the chains control the cutting height. If it's too low or too high, raise the lift and adjust the chains longer or shorter.

This is the most dirt-simple, fool-proof way to set cutting height without buying a finish mower with four wheels.

 

[RICHMONDRON]

Makes sense. I may do that to get me to the winter and do a rebuild then if the lift will raise it that long.

Thanks.

 

[Anonymous-0]

JMOR, I've always wondered what the heck does the cam follower pin do?
Now, thanks to your explanation, I know.

Joe

 

[Bruce (VA)]

Yea, hang some chains off of it for now.

Rebuilding the top cover is no big deal. Half a day if you're good w/ a wrench, all day if you're not.

Are you in Richmond VA?

50 Tips

 

[KL-VA]

As long as the pump can keep up with the leak, the lift will still work. Two minutes is not too bad. My first 8N would drop in about ten seconds, but seemed to have no trouble lifting.

If you are in Richmond, VA Bruce and I have you surrounded, GRIN.

 

[ZANE]

Are you sure the little mode lever under the seat on the right side is in position mode??? Little lever up. Down is draft and that is how draft is supposed to work.

Zane

 

[RICHMONDRON]

Zane,

The behavior of the lift is the same in either the up or down position of the draft control lever. I'm alsmost willing to bet that the cam follower pin is completely worn through basically doing away with the draft control function. No pin to cam contact = no movement in control rod = no draft control. Correct?

 

[RICHMONDRON]

Well Howdy neighbors! I'm actually in Hadensville. Richmond is just the closest metropolitan area.

 

[RICHMONDRON]

Actually Hadensville. Richmond is the closest "Big City" so I grabbed it for an identifier. Since just plain Ron was already taken, I was forced to get creative!

 

[Bruce (VA)]

Kevin is closer (in Louisa); I'm in Old Church (eastern Hanover Co).

Check in when you're ready to do the lift cover. One or both of us can help.
50 Tips

 

[ZANE]

You have it backwards. If in fact the cam follower pin is worn out and not making contact with the cam it will act like it has only "Draft" control. Position control is when the lift stops at a given height in conjunction with the position of the touch control handle.

The cam pin being not working is not the only thing that can cause the position mode not to work. If something has come loose in the position linkage it will do the same thing.

Zane

 

[mrbinks808]

Great I'm really glad I stumbled onto this site. I'm having the same issues and have been told that adjusting the pin to get everything right is a real head ache I know I'm going to be saving some $$$ to get Zane's Jig and manual.