Offset disc-up close and personal

[flusher]

Thought there might be some interest in what I'm doing to salvage/refurbish an ancient 6-ft wide offset disc I got from my neighbor. It was in the weeds when he bought his place 14 years ago. No ID tags, but it may be an old Towner. Any help here is appreciated. Plan to use it with my 1964 MF-135 diesel to do a little haying on 7 acres. It's one heavy sumgun. Wonder what something like this costs new.

The disc has two four-disc gangs (20" dia discs) on the left side of the frame and two five-disc gangs on the right side. It appears that the previous owner(s) used it in the clockwise direction since the outer three disc on the right front are worn down several inches. Need to disassemble that gang and replace the worn discs so the implement is level.

Used the Kubota B7510HST and LA302 FEL to lift the corner of the frame.

The discs are pretty rusty, but not too corroded.

I had to cut the large square nut off the end of the axle with my Makita 4-1/2" grinder. Tried the usual penetrating oils for several weeks, but the threads were dry after I pounded off the nut. Messed up the threads a little. Need to clean these up later.

Next job is to remove the bearing block near the end of the axle shaft. Two bolts with 1" square nuts. None of my sockets or box end wrenches fit. Too tight for a cresent wrench. Need to visit the NAPA store in town and get the right tool.

Still trying to get the adjustment mechanism freed up. Penetrating oil seems to be working here. Need to figure out how to work that mechanism loose. Probably have to chain the rear end of the disc to the Kubota and hitch the MF-135 on the front and pull.

It's a real contraption. Looks like the skinny rod with the loop on the end is the release that frees the adjustment mechanism so the angle between the two halves of the disc can be adjusted. I suppose you pull this release while easing the tractor forward or backward to change the angle.

Don't know what that J-shaped piece on the right side in the photo is used for. Any suggestions? There's a length of chain there also that I haven't figured out yet.

More to follow as I make progress.

 

[MtnViewRanch]

Does the end of the J look like it has been cut off? There should be a hole there to hook a chain to. Offset disks are made to be pulled counterclockwise. Very very hard on them to turn to the right. That J bar is there to release the disks while you are disking so that they can be turned to the right. If the mechanism is all there, what you need is a similar length bar fixed to the back of your tractor. Connect the two bars with a chain and supposedly whenever you need to turn to the right the disks release so as not to damage the disk. My 6' Kilfer disk is the same way, but I have never hooked up the release.

 

[flusher]

Does the end of the J look like it has been cut off? There should be a hole there to hook a chain to. Offset disks are made to be pulled counterclockwise. Very very hard on them to turn to the right. That J bar is there to release the disks while you are disking so that they can be turned to the right. If the mechanism is all there, what you need is a similar length bar fixed to the back of your tractor. Connect the two bars with a chain and supposedly whenever you need to turn to the right the disks release so as not to damage the disk. My 6' Kilfer disk is the same way, but I have never hooked up the release.

Thanks for the info. As I mentioned before, it looks to me like this disc has been turned clockwise since the wear is on the right front disc gang.

I managed to get a copy of the assembly and operating instructions for a Towner off-set disc harrow (Series K, KL, KO, KH and KOH). No date on that document but it looks like it is way over 50 years old. My disc is not one of these, but I figured getting a manual for a vintage offset disc is a good way to learn how these things work.

There's a half-page of instructions to set up the Towner disc to make a right hand turn. I'm still trying to figure out how the Towner disc works and hope that tells me something about the one I have.

 

[flusher]

Does the end of the J look like it has been cut off? There should be a hole there to hook a chain to. Offset disks are made to be pulled counterclockwise. Very very hard on them to turn to the right. That J bar is there to release the disks while you are disking so that they can be turned to the right. If the mechanism is all there, what you need is a similar length bar fixed to the back of your tractor. Connect the two bars with a chain and supposedly whenever you need to turn to the right the disks release so as not to damage the disk. My 6' Kilfer disk is the same way, but I have never hooked up the release.

To answer your question: I don't think the end of the J handle looks like it's been cut off. There is a chain attached to the adjustment mechanism.

I assume that's the chain you're referring to.

Assuming that the disc is adjusted with a non-zero angle between the front and rear gangs while pulling in a straight line, what happens in a left-hand turn? Do you want the disc to cut more aggressively (bigger angle) or less aggressively (smaller angle) in a turn?

My tractor implement education continues.

 

[bjcsc]

Get rid of the grinder and get a torch. Every one of those nuts will come off when they're red hot - and you'll be able to put it back together - and you don't need any power...

Good find, though!

 

[MtnViewRanch]

I have to 2nd the torch deal. Waaaay easier.

The blades of the disk that show the most wear ARE the ones that wear first and the most. The disks that are in the leading gangs wear substantially more than the others. I seriously doubt that the disk was pulled making right turns very often. If it was, the mechanism to release the angle was used. When you go out and use the disk, try a gradual right turn and you will see that you wouldn't want to do that on a regular basis without the release mechanism.

I do not know about the chain, it seems to me that the chain should be connected out at the end of the J bar, similar to the schematic drawing of the bar on the back of the crawler. As far as the angle on the disk while pulling, for the first few passes I would have the angle set for maximum. When you turn left the disk actually pops up out of the ground and stops digging on its own. The sharper the turn the more that it will come out of the ground. If when you have gotten the ground disked and you make about as hard of a left turn that can be made, the disk will just move sideways in the soft soil instead of popping up and out of the ground. Not sure what type of ground that you have, but where I am with that disk in virgin ground you would be down to the axles with 3 passes for sure.

My 6' disk is not all that much better than yours as far as the condition that it is in, but I don't use it much if at all, just got a good deal on it. Let us know how it works for you. Seems like I'm forgetting something, I'll post if I remember.

 

[KSopocy]

Good luck pulling the beast with a MF 135. You will find out how many ponies you wish you had, especially if you get crazy with the offset. I have seen a 12 ft offset bring a 250 hp 4x4 to her knees. So your 6 footer will make the old MF grunt and snort and probably spin out.

 

[KSopocy]

Oh those outer discs are supposed to be a bit smaller. See attachment of a much larger unit

 

[Glowplug]

Oh those outer discs are supposed to be a bit smaller. See attachment of a much larger unit

View attachment 87111

On your attached photo ALL the discs are so small I need a magnifying glass to see them.

 

[tippytappy]

I managed to get a copy of the assembly and operating instructions for a Towner off-set disc harrow (Series K, KL, KO, KH and KOH). No date on that document but it looks like it is way over 50 years old. My disc is not one of these, but I figured getting a manual for a vintage offset disc is a good way to learn how these things work.

Flusher - where did you find the instructions / manual? I recently obtained a Towner off-set disc harrow and really have no experience with this sort of thing. Towner is obviously no longer extant; the only references to manuals I've found are in the archives of UC Davis. Thanks...