Another Top N Tilt Question

John_Mc · Oct 10, 2001

I recently added TNT to my NH TC33D. After a few teething pains (thanks for the pointers, Bird) I'm starting to get used to it. I put on the box blade yesterday for the first time (I know, I know... why do you need TNT for brush hogging?!). I've noticed two things that don't seem right:

1) I believe the link is too long. It will only rotate about 2 or 3 degrees forward of level, but rotates back about 17 or 18°. Forward doesn't seem like enough, rear is probably more than I'll ever use. I don't really have a good area to test it out at present, since I can't randomly tear things up until the site for my septic system gets defined. Anyone have a good idea of what a normal working range for of forward/aft rotation on a box blade is? I've only used it a few times with the old manual link, and it seems I was farther forward when using the scarifiers. I have a call in to the dealer who installed it to see what the next size shorter cylinder is.

2) I believe there must be air in the system somewhere. If I rotate the box back a bit, then lower it onto the ground, the top link cylinder compresses 3/4" or so just from the weight of the box on the ground. If I pull forward to put it under a slight load, it compresses even more. (Could any of this be related to the fact that one of the fittings was not even hand tight when I received it? It did not get any heavy use in this condition, but I did move the cylinders around quite a bit before I noticed and tightened it up).

Thanks for any info any of you can provide.

John

Bird · Oct 10, 2001

John, it does sound as if your hydraulic top link is too long. When I did mine, I measured the original equipment manual link, both fully extended and fully retracted, and wanted the same length. The one I bought was close, but no cigar. And sure enough, I had about the same problem you have with the length. I could have done it myself, but instead took the cylinder to a hydraulics place and had it shortened on both ends.

As for your second problem, I never had that happen. I had a tractor dealer tell me to move the lever to fully extend the cylinder and hold it there awhile (which will open the tractor's relief valve), then do the same thing in the other direction, etc. to bleed any air out. I just didn't have to do that myself. It never seemed to have any air to have to get rid of.

I posted pictures of my box blade tilted all the way forward and backwards after shortening the top link, but they are probably not in that thread anymore.

Bird

Bird · Oct 10, 2001

John, I looked up the old pictures of my box blade tilted both directions (sitting on a concrete floor) after shortening the top link.

Bird

Harv · Oct 10, 2001

I posted pictures of my box blade tilted all the way forward and backwards

Here's the picture you posted of the box tilted forward, and the other of the box tilted backward.

Or were you thinking of some other picts?

Bird · Oct 10, 2001

Good timing, Harv./w3tcompact/icons/wink.gif I had looked back at the old thread and didn't find the pictures, so I found them on my computer and we posted them at the same time apparently./w3tcompact/icons/laugh.gif

Bird

glennmac · Oct 10, 2001

Bird, it appears that your valve levers travel side-to-side. If you did it over again, would you stick with side-to-side or go front-to-back. I guess I'm asking your opinion on the pluses and minuses of the geometries in actual use.

Bird · Oct 10, 2001

Glennmac, I would prefer front-to-back but couldn't figure out a good way to mount them that way. Of course, the only real concern I have with the way they're mounted is the possibility of limbs catching on them if I get into brush or trees.

Bird

John_Mc · Oct 10, 2001

the old pictures of my box blade tilted both directions

Yep, you've definitely got more forward tilt than I do. On mine, you have to look very closely to see that it's not level. It only goes 2 or 3° forward of horizontal. (measured with an old roofing square as a protractor, and a level sitting on top of it).

Question: as you've got it now, do you find yourself using the extreme range of your settings in normal operation? I'm giong to try the next shorter cylinder, but don't know if that's going to shift me too far the other way or not. I'm guessing I could spare an inch or two without losing too much backward tilt, but haven't heard back yet what the next size shorter is.

Bird · Oct 10, 2001

I do sometimes use the extremes, but probably never really need to use the extreme backwards tilt. And about the only time I need to go to the extreme in either direction is when I'm dragging a bucket full of dirt over a hump or ridge and don't want to dump any of it there. I had to shorten the cylinder 1" on each end and it wouldn't have hurt to shorten it another half inch or so; however, I'm quite satisfied with it the way it is now.

Bird

hayden · Oct 10, 2001

Can you measure your old manual link in it's fully open and closed positions? Ideally you'd want your hydraulic top link to reach the same lengths. As Bird pointed out, that's often easier said than done. I ended up with some (fortunately) minor compromises on mine too, and it was custom made at that.

You'll need to watch two things, one is the close length of the cylinder, and the other is the stroke length. I'm embarrased to say I don't recall what the stroke is on mine, but I think it's 8", and it's all needed to get the reach you need. In my case the problem was getting the whole assembly short enough when closed to avoid having to get a shorter strok cylinder that would then compromise the extended length.

High techie, reciently founded a startup company and struggling for tractor time.

JRP · Oct 11, 2001

John,

My top link compressed some when it was first installed. I operated to extremes several times and most compressibility went away. I suppose you could temporarily set your cylinder such that the hosesare are up and let air rise toward the valve. Operate the lever driving the cylunder to extremens to cause gravity to force the air up and out.

My top link is 8" stroke. A typical top link has an adjustment range from 19" to 29". A 10" adjustment. But my cylinder is 8" stroke, so I have already lost 2" of stroke. The limiting factor in my setup was the length of the end caps and rod end. For this reason, I fabricated a rod end that screweed on the rod threads, then cut off the rod a short as possible while still getting good thread engagement. The tractor end of the cylinder has been adapted such that the cylinder is as close as possible to the pin hole as would fit.

Desierd Result: Get the most stroke in the shortest possible package. Modify the cylinder ends/adapters, not the stroke, if at all possible.

John_Mc · Oct 11, 2001

Thanks, everyone for your tips. It looks as though I'll have to shorten my cylinder on both ends. I checked, the next size down that is easily available is MUCH too short (not to mention shorter stroke).

I've also got to get the dealer to move my hydraulic side link over to the right side. He put it on the left, which is a pain, since the control is on the right. Also, the hoses are already chafing on the top link, even with only a few hours of operation. I had asked for the right side, but apparently they forgot.

Bird · Oct 12, 2001

John, my cylinder also has the 8" stroke, and you wouldn't want any less. The Tisco cylinder I have, had what I'd consider an extra long rod and an extra long connection on the other end, too, which allowed shortening the ends pretty easily without affecting the stroke.

Bird

John_Mc · Oct 12, 2001

Bird - Sounds as though you've got the same cylinder I do. I think it's a Tisco. 20" retracted, 28" extended (at least until I get it cut down).

Keoke · Oct 12, 2001

John, you want the hyd cylinder mounted on the side opposite of the crank tilt adjustment. This will give you the max tilt angle range.
It really makes a difference when doing a ditch with your blade.

george

Bird · Oct 12, 2001

Yep, John, sounds like the same cylinder; Tisco model HTL2102.

Bird

John_Mc · Oct 13, 2001

you want the hyd cylinder mounted on the side opposite of the crank tilt adjustment.

George - Thanks. I was aware of that. I plan on putting the manually adjustable link on the left side, in place of the fixed link.

Three reasons:
1) my controls are on the right... it's easier to see the adjustment while operating the controls if you can turn to the same side the controls are on.
2) the remote outlets are on the right; the hoses have to cross over the top link to get to the hydraulic cylinder on the left side. I've only used this a few times, and the hydraulic lines are already starting to chafe on the top link.
3) the hydraulic lines to the side link on the left make it a pain-in-the-butt to disconnect the PTO shaft (side link lines make it tough to raise the top link, which makes it tough to raise the PTO guard.)

John_Mc · Nov 6, 2001

Finally got my top link cylinder back from the dealer. I decided to try just cutting the back end off short - had them cut out the flat stock, and reweld the ball joint right on to the back of the cylinder. I looks as though I'll be able to get away without cutting down the cylinder shaft.

I'm still getting some significant compression of the toplink cylinder under load. The service guy who put the system on said all I need to do to bleed the air is operate the valve to the extremes in both directions, and hold it there. I did this, and still get 3/4" compression of the cylinder even under a light load (i.e. lowering the box blade to rest on the ground). If the seals in the cylinder were damaged, would this be one of the symptoms? I don't see leaks anywhere.

Bird · Nov 7, 2001

John, I don't know enough to say for sure, but it does sound to me like you have a bad seal in that cylinder. The service guy was right about bleeding the air; that's the way I was told to do it, too, although even that was not necessary on mine. Reckon they took the cylinder apart before welding? Otherwise they may have overheated the seal. And then of course, it's always possible to get a new defective product. My top link cylinder had a pinhole leak where they welded the hydraulic line fitting onto it when they made it; just took a little welding to fix it, but needless to say, I'm not too favorably impressed with Tisco products.

John_Mc · Nov 7, 2001

Thanks Bird-
Is there an easy way to check the seal, or is it basically a matter of disassembling the cylinder and looking?

If the seal were leaking, would you expect the position of the top link to keep drifting under load until it hit the end of it's travel? If this is so, is that different from air, where it might stop after a certain amount of drift?

John