MF 31 Sickle Mower Refurbish

[Optiker]

I have two sickle mowers, a New Idea (NI) 30 that had sometime in its past been modified from pulled to 3-point, and a Massey Ferguson (MF) 31. I used the NI until the cast connection between the Pittman and the cutter bar broke, then bought the MF 31 to replace it. I was not experienced enough to realize that the MF was not in very good condition, but have since learned much. When it increasingly jammed, I learned a little and made some adjustments. It repeatedly broke the bolt that connected the cutter bar to the Dyna Balance arm. I finally gave up in frustration and payed my neighbor to mow (about 3 acres of grass hay, 3-4 cuttings/year) with his disk mower. Over a period of about three years, his mowing deteriorated and last fall, I told him that because it was leaving too much behind, I would try to get my sickle mower back in service. That gets me to my problem.

I've pulled the cutter bar of the MF 31, and removed all of the guards, hold down clips, wear plates and shims. I also removed the sections, which were all bad, with the exception of maybe two that were marginal. The ledger plates were all very bad. All of this probably explained the jamming, and probably also the broken bolts. Some of the guards had broken or bent "ears". There was a mix of guards including about half that appeared to be original MF, one that was a later MF, but not the correct one since it didn't match the beveled bottom front edge of the bar, and four other miscellaneous guards other than MF branded.

I pulled the guards from the NI mower, and found the ledger plates were a little worn, but not bad. That mower had cut pretty good. I also recalled that I had replaced most of the sections so that they were also in pretty good condition. Before pulling them to reinstall on the MF mower, I compared cutter bars and found that the NI bar was 2-3" longer than the MF bar, and by shortening it and re-drilling the holes for the connector bar, it looks like I can use it as-is (with already installed sections) in the MF mower.

So, the current plan is, use the NI guards on the MF bar, and modify and use the NI cutter bar in place of the MF cutter bar. I will also use wear plates, shims, and bolts from the NI as needed, and as they fit.

The questions... (1) Are the shims of different thickness so as to provide an adjustment, or are they for some other purpose? (2) How badly worn can the wear plates be and still be usable? (3) is there a web site where I can find a step-by-step overhaul/restore process description and/or a general checklist for things to check on a mower to make sure I've done all I can to make it work right? I don't really know anything about adjusting wear plates, though I understand the process of adjusting hold-down clips and ledger-section clearance. (4) Any comments on this approach?

As you might guess, at 3 acres of hay, this is really just a hobby, which makes dumping a lot of money into a new mower, or into a lot of new parts, not justifiable. I also don't know enough about tuning sickle mowers to know if even replacing all guards, sections, wear plates and shims with new, will result in a mower that does the job. The rest of the mower seems good, but I'm not experienced enough to know. That's also why I don't go looking for a replacement used mower - I don't care to spend a lot of money and have a mower that still needs this kind of work to get it working. I noticed on one of the sickle mower sites that I could buy a MF 31, claimed to be in excellent condition, for about $1700 - but it's in Kentucky and I'm in WA!

The rest of my equipment includes a MF35 tractor (Perkins diesel), an old Ford side-delivery rake, and a John Deere 214WS baler (wire). When I first got it, the baler would fail to tie about 1 out of 3 bales. Over the period of a couple of years, we got it to where it is now, and rarely fails to tie, with the exception of the first bale in an empty chute.

Any help would be greatly appreciated. FWIW...there is some time pressure since I've scheduled to mow my first cutting on 8 May. If no sickle mower, I guess I'll have to settle for my neighbor doing it and leaving probably 1/4 to 1/3 unmowed, that would otherwise be mowed with a sickle.

Thanks for any help you can provide!

Optiker

 

[flusher]

I have a MF31 mower that I bought at auction for $550. Rebuilt it several times--about $200 in new parts. Still not working 100% correctly.

Shearing that bolt could be due to a number of things: worn knife clips, worn guides, guards out of line, loose sections, worn knife head, cutter bar misalignment.

Jamming could be due to excessive ground speed.

The shoes should be set at equal heights. Under normal conditions the shoes are both in the raised position. If the field is trashy, the shoes should be lowered as much as possible.

You can download the operator manual here

Massey Ferguson MF31 Sickle Mower - owner's manual

Good luck.

 

[Optiker]

You can download the operator manual here

Massey Ferguson MF31 Sickle Mower - owner's manual

Thanks flusher! I already have the operator's manual. Would like to have a service manual, but don't know if there is one and never found one when I was looking for the manual years ago. I have read the service section of the operator's manual, but it's pretty limited.

Optiker

 

[flusher]

Can't help you there--don't have either a service or a parts manual for my MF31.

 

[Sodo]

Very interesting, and in WA. Optiker are you fed up enough to sell that MF31? I have an MF31 that's in very good condition but I need a wobble crank. Or the whole wobble box. Or a whole spare mower. Grass is growing, I need to get my mower fixed, so if you're done with that one please reply to this thread or send me a PM with a tel#.

 

[Optiker]

Hi Sodo...

I can't quite give up on it yet. I'm scheduled to mow on Thursday and don't have an option, so I'm putting it back together, with the adapted cutter bar from my old NI31, as many guards as I have from the MF31 that fit properly, and the new parts for the link between the wobble box arm and cutter bar. I'm short three guards, but when I get some ledger plate rivets, I can have one more - still short two.

I have found that the critical dimension on the guards - other than the bolt hole location - is the vertical distance between the plane of the top of the ledger plate and the plane of the surface where the guard contacts the underside of the bar. It looks like it needs to be about 5/8" or a little more. The guards I've been able to find, as well as those from the old NI30 mower - even the ones that are listed for the MF31 by the places I've tried - are closer to 1/2". That puts the ledger plate surface too far below the bottom surface of the sections. Bending the guards up or shimming them tilts the ledger plate so it might close the gap at the front of the ledger plate, but leaves too big a gap at the back. I haven't seen a way around that, so unless I can find some guards that fit, I may end up leaving those last couple of guard locations empty and mowing as-is. I don't know what problems that might cause.

Many of the ledger plates are badly worn, but I'll have to take my chances for now. If I can find some ledger plate rivets, I can pull the ledger plates from some of the old, unusable NI30 guards that are in pretty good condition, grind a touch from the semicircular notch, and use them on the MFG guards that fit.

If I can't get my MF31 working by Thursday, and can't find somebody to come in and cut it, my only option is to bush hog it and bale what I get. The bush hog I have access to doesn't have removable sides, which, if it did, I understand doesn't chop up the hay as badly. It's a real shame to lose so much by bush hogging, but that's a last resort. This is mixed grass hay, and a lot of it is knee high or more.

I'll let you know if I decide to buy another mower and get rid of this one. I've looked at a JD350 that has possibilities.

Right now, I really feel like I'm in a corner with no really good options.

Thanks for your interest.

Optiker

 

[Optiker]

In reading through Sodo's thread from January, somebody gave a link to the Agco parts book. That was a bad link that didn't work. I don't have the parts manual for my MF31, just the Operator's Manual. I'd really like to have access to the parts manual for a couple of reasons. Does anybody have a good link to an online parts book that I can look at? Or, if anybody has one and can post a scan or snapshot of the parts I'll describe below, I'd sure appreciate it.

The first of the two things I need to look at is the exploded view of the link between the wobble box arm and the cutter bar. I have the new parts, but it's been so long since I took it apart that I've forgotten just how it goes together. I think I can figure it out, but would feel more comfortable if I had a reference to confirm.

The second thing I need to look at - if there is an exploded view - is the assembly of the guards on the bar, with the hold-down clip, wear plate and shim. My wear plates are flat, but the Operator's Manual shows a cross-section that shows L-shaped wear plates that makes more sense. My wear plates from the old NI30 are L-shaped and still usable, so I have installed them. I haven't used the shims at all since the only function I can see for them is to raise the hold-down plates for greater clearance to the section. That adjustment is by hammer, so I can't see why the shims are needed. Some of the shims are narrower and fit properly, some are too wide. I'd like to know for sure how that assembly goes together.

Any help with a parts manual or comments on the two issues would be greatly appreciated.

Thanks!
Optiker

 

[Optiker]

I have another question regarding guards. I have now re-installed the guards as I described in an earlier reply to Sodo. It bothers me that there is a good bit of variation in the gap between the ledger plates and the sections. Some are in contact and will need to be adjusted. Some are as much as 1/8", and I'm not sure if that's too much to adjust or not. All that I've read says you adjust with a small sledge hammer to bend the malleable guard up or down. That's fine for the malleable ones, but not any that are cast iron. On my old NI30, I always just shimmed between the guard and the bar at the back edge to tip it up or the front edge to tip it down. I know that works OK for small adjustments, but not sure when it gets as much as 1/8". Doesn't that cause a problem with the gap being a wedge instead of even between the ledger plate and section?

Any solution?

Thanks!
Optiker

 

[GreenWannabe]

Try this link for your parts book:

http://www.agcopartsbooks.com/PartsBooksN/Viewer/book.aspx?book=agco/651025

If that doesn't work for you, go to Agco Parts Books, click on the View Books button next to the Guest User heading, and then search for your 31 mower in the Massey Ferguson brand section. You'll have to page down on the results page to get to it, but it is there, even if some of the parts themselves are NLA. Good luck!

 

[Sodo]

I can't offer much help, the whole of my experience with sickle mowers is from disassembling this MF 31 and searching for a crank repair. I may be able to offer pics though, it's possible mine is mostly original assembly.

Sounds like you're deep into it. It worries me a little that you are having trouble getting the right guards. My bar was very "recently" rebuilt, with new cutters and new guards and slides very nicely. The guards have new paint and haven't cut many weeds, but I guess it could have been done many years ago, just before the wobble crank broke.

I'm curious, how much is 3 acres of hay worth? I have about that much too but was just planning to mow about an acre to cut the knapweed and because it looks nice but if its worth something maybe I'll think of it differently.

If anyone else out there has parts for the MF31, (wobble crank and the adj. sheave) I'm very interested!

 

[Creamer]

This is simple. Since you are talking about ledger plates i am assuming that you have the older, thicker mower style guards and not the newer haybine type. these are more difficult to adjust than the newer ones but it can be done.

Assuming your cutter bar and sickle bar are straight:
1st - it sounds like you have different styles of guards mixed on the cutter bar. Try to get the same styles grouped so you do not have a lot of transitions.
2nd - Install the wear plates behind the sickle in the most retracted position possible. Then check for contact of the wearplate with the sickle in the fore/aft direction and adjust so that they are all just touching the sickle bar. You should replace any wearplates that are worn more than halfway through. You can push this limit some but you do not want a wearplate to give out while you are cutting.
3rd - check guard to bottom of section clearance (assuming you have decent sections and that they are not bent). Adjust the guards up or down - any guard including the cast ones because I do not know of any that are not - using a hammer and hitting near the tip of the guard. You can also use a pipe over the end of the guard. I can never remember breaking a guard this way unless it was previously cracked. The sickle should lie flat on the ledger plates - if not you have guard style issue but most are interchangeable.
4th - adjust the holddowns via tapping with a hammer so that they are just touching the top of the sickle sections.
5th - verify your sickle moves easily. I am not familiar with the MF machine but you can turn a pulley or take the drive loose and move the sickle by hand. You should not have to pound on it.
6th - start the tractor and run the sickle and watch and listen - watching for for aft movement and any jerkiness and listening for rattle. shut the tractor off and check for any catch points or heat build-up. You should not be able to see the sickle catching and anywhere and it may be a little warm but certainly touchable. If it is hot you have it constrained to tightly and would not have passed #5
7th - lubricate the sickle with used oil at all the wear plates and hold downs. I prefer using a Dawn Dishwashing detergent type squeeze bottle which gives me control and keep my hands away from the sickle. Now when you run it you should hear much less noise.

You should be ready to go.

Basically you have ti give the sickle a straight path to run in and constrain it so it does not bounce around. Then make sure you have not overconstrained it and make sure you maintain the scissor like action between the section and the ledger plate. Personally I have never seen ledger plates wear out. i have seen them rusted beyond any degree of sharpness and need to be replaced and other types of damage but it has had to have lots of use to have been worn out. Last year I bought a sickle bar mower from the 60s that had been used on a dairy farm for 30 years and then not run since but stored inside and the ledger plates are in fine shape.

Good luck!

 

[Optiker]

Try this link for your parts book:

http://www.agcopartsbooks.com/PartsBooksN/Viewer/book.aspx?book=agco/651025

If that doesn't work for you, go to Agco Parts Books, click on the View Books button next to the Guest User heading, and then search for your 31 mower in the Massey Ferguson brand section. You'll have to page down on the results page to get to it, but it is there, even if some of the parts themselves are NLA. Good luck!

The first link didn't work, but the one to Agco Parts did. Thanks very much!
Optiker

 

[Kioti Tom]

Go to Amazon.com and look up MF31 manuals. the Parts manual comes up as
one of the manuals.
Tom

 

[Optiker]

Personally I have never seen ledger plates wear out.

See the pictures. These are both currently reinstalled on the mower. The shiny one isn't rusted because I took it off when the mower broke last time a few years ago and had it in the barn. The rusted one stayed on the mower, outside, but under a shed roof. You can see on the shiny one the worn groves trailing away from the notches in the serrated edge. The other one is just so badly worn that there is no longer serrations in the middle of the cutting edge.

Incidentally, notice the gap between the ledger plates and the sections. That's probably the worst, while with some guards, the section is actually contacting the ledger plate. I'm about to go out and try to align everything!



Optiker

 

[Optiker]

I thought I'd send along a picture showing the variation in the various guards, including one which I am guessing is an original, since it's the only one with a bevel to match the underside leading edge of the bar, one stamped MF, which I assume was installed later, but has no bevel, and one that is a generic that I took off my NI30, hoping it would fit. The thing to notice is that the measurement between the flat that contacts the underside of the bar when the guard is installed and the top surface of the ledger plate is different for each of the three. For the two that aren't the original, the smaller measurement means that the ledger plate surface is well below the bottom surface of the sections - probably too much to adjust.

Also notice that only the original one has the bevel. The middle one - the one stamped MF that has no bevel - was on the mower when I got it, and I used it that way until the mower finally broke. I suspect that too-big gap was a part of the jamming problem.

FWIW!



Optiker

 

[Creamer]

See the pictures. These are both currently reinstalled on the mower. The shiny one isn't rusted because I took it off when the mower broke last time a few years ago and had it in the barn. The rusted one stayed on the mower, outside, but under a shed roof. You can see on the shiny one the worn groves trailing away from the notches in the serrated edge. The other one is just so badly worn that there is no longer serrations in the middle of the cutting edge.

Incidentally, notice the gap between the ledger plates and the sections. That's probably the worst, while with some guards, the section is actually contacting the ledger plate. I'm about to go out and try to align everything!

View attachment 373882 View attachment 373883

Having nice sharp edges would be nice but the real issue with ledger plates is the crown, i.e. higher in the middle than on the edges which creates a gap between the sickle section and the plate. Gap is what typically causes the crown as the grass drags across the edge wearing it down. The vertical gap between the section and plate is a big issue.

BTW - you can take a grinder and grind the edge of the ledger plate vertically to remove the serrations but put a sharp edge for better cutting on it. The haybine style guards have no ledger plates or serrations and cut just fine. I grew up cutting a lot of tough native "prairie" hay with them in the Dakotas. The serrations are not necessary. Today's tame hays are much easier to cut.

 

[Creamer]

I thought I'd send along a picture showing the variation in the various guards, including one which I am guessing is an original, since it's the only one with a bevel to match the underside leading edge of the bar, one stamped MF, which I assume was installed later, but has no bevel, and one that is a generic that I took off my NI30, hoping it would fit. The thing to notice is that the measurement between the flat that contacts the underside of the bar when the guard is installed and the top surface of the ledger plate is different for each of the three. For the two that aren't the original, the smaller measurement means that the ledger plate surface is well below the bottom surface of the sections - probably too much to adjust.

Also notice that only the original one has the bevel. The middle one - the one stamped MF that has no bevel - was on the mower when I got it, and I used it that way until the mower finally broke. I suspect that too-big gap was a part of the jamming problem.

FWIW!

View attachment 373886

Optiker

I am missing what you are trying to show me in these photos.

The distance from the actual bar to the back of the guard is not an issue as long as the sickle has a straight path to run in. If the sickle has a straight path and it is properly constrained the rest should not matter.

One thing I did forget to mention in my list is to check the lead. The outside end of the sickle bar should be about 3" ahead of the head end when everything is setting on mice level ground (assuming you have a 7-9' sickle bar). This is because the whole mower twists slightly as drags on the ground in the dynamic world of mowing and so the lead is just compensation for the drag.

 

[Optiker]

BTW - you can take a grinder and grind the edge of the ledger plate vertically to remove the serrations but put a sharp edge for better cutting on it. The haybine style guards have no ledger plates or serrations and cut just fine. I grew up cutting a lot of tough native "prairie" hay with them in the Dakotas. The serrations are not necessary. Today's tame hays are much easier to cut.

Hadn't thought of grinding off the serrations. That might be a good alternative to new ledger plates. I found a source of them in small quantities at only @$1.25, so cost isn't an issue, but time to do it is, and I haven't found rivets yet. I can order those by the pound, even though I just need a few. I've also been told numerous times that smooth sections rather than serrated are recommended for grass. My intuition is contrary to that, but so be it. Nevertheless, all of my sections are serrated.

The gap is definitely an issue. I'll work at that today.

Also, I have an opportunity to buy a JD 350, and when I looked at it, it had no ledger plates...first time I ever heard of that.

Thanks!
Optiker

 

[Optiker]

I am missing what you are trying to show me in these photos.

The distance from the actual bar to the back of the guard is not an issue as long as the sickle has a straight path to run in. If the sickle has a straight path and it is properly constrained the rest should not matter.

One thing I did forget to mention in my list is to check the lead. The outside end of the sickle bar should be about 3" ahead of the head end when everything is setting on mice level ground (assuming you have a 7-9' sickle bar). This is because the whole mower twists slightly as drags on the ground in the dynamic world of mowing and so the lead is just compensation for the drag.

The issue here is the vertical distance, when the guard is installed, between the plane of the top of the ledger plate and the bottom of the bar - the bottom of the bar being the surface of the guard (shown in the pictures) that is in contact with the bar when it is installed. Imagine taking a guard that is properly installed and shimmed so that the gap between the ledger plate and the bottom of the section is as it should be. Now, imagine putting an 1/8" shim between the guard and the bottom of the bar and tightening it down. That would result in an 1/8" gap between the bottom of the section and the ledger plate. That's effectively what happens when I install the "generic" guard since that measurement is only about 1/2" compared to the "original" guard at 5/8". It has nothing to do with the distance from the back of the bar to the back of the guard.

I haven't checked lead yet, but eyeballing, it looks pretty good. Yes, it is a 7' bar.

Thanks!
Optiker

 

[Sodo]

The issue here is the vertical distance

Agreed

Is this pic "in use"? Or is it partially disassembled?

I can't imagine how that could do ANYTHING but fold the weeds in half and jam them into the guard. The shearing edge of the section needs to slide directly on the guard below, to create the shearing action.

What is causing the section to rise so far above the guard? Is the sickle 'track' full of weeds, lifting it up? Is the bar bent? Is there a block that rides ontop of the sicklebar keeping each cutter section down low against the shearing edge (that you may grind sharp) of the guard?