MF #41 Sickle mower blade replacement

[DougMF41]

I'm trying to connect the blade bar to my MF-41 and can't find a photo anywhere on the internet that shows how the holes line up between the bar, link and blades. I think the link I have (black in the photo) may not be original and may be why I'm confused. It doesn't line up the way I would expect it to. Anybody got a photo?

 

[Phil Tibbetts]

I'll try to remember to get a pic of mine today.

 

[FarmerJones]

I just measured the two knife bars that I have.
The spacing of the holes is:

. 3/4 . 3/4 . 7 7/16 . 2 1/8 .

The bar is thicker under the head.
Hope this helps.

 

[FarmerJones]

The bar that the head is fastened to is a spring and the three holes do not necessarily align with the holes at the end of the knife bar. It's the spacing between the last head hole and the first section hole (7 7/16") that is important.

 

[DougMF41]

Thanks for the part diagram. I can't make out the numbers on it. I'm assuming that the head is the part that is on the drive housing right now, it has 3 holes in it. The spring is the steel bar that connects the head to the knife bar. The knife bar is the steel bar that all the blades are bolted to.

The last head hole is the outermost hole?

I don't understand what you mean by the first section hole.

 

[FarmerJones]

Correction:

The hole spacing is . 3/4 . 3/4 . 7 7/16 . 3/4 .2 1/8.

I misread my rule.

By the first section hole I meant the first hole where the spring connects to the knife bar. That is the second hole in the third full section.

Go to http://www.agcopartsbooks.com and sign in as a guest. You can enter the model number and select MF and see the complete parts list with diagrams.

 

[FarmerJones]

The dimensions are for the holes in the spring. The one that you are hold looks like it might be OK. The three holes on the spring do not align with the three on the knife bar.

 

[DougMF41]

So sections are the teeth. Learn something every day.

 

[DougMF41]

The spacing on mine between the last head hole and what I would call the third section hole is 7-3/8. But the two holes that come before that hole are smaller diameter. Are they not section holes?

 

[FarmerJones]

7 3/8 should be good; difficult to measure the center of the rivet. They deform somewhat when installing. Here are three photos.
One on the mower and two of the spare. You can see the space between the spring and the knife bar. Overall length is 17". Don't know what the first tow holes are for. They are not factory.

 

[DougMF41]

Look at my photo and noticed the red circle. You appear to have a 4th hole in the end of your knife bar that I don't have at that red dot location. It goes through the middle (approximately) of your first section. My mower never had a section with a hole near the middle. Am I wrong? I'm still confused. Something is not right here.

 

[DougMF41]

Or is it that your first blade, (that rectangular shaped blade) has only one rivet going through it? Is the innermost edge of it hanging over the inner most edge of the knife bar? I never thought when I pulled this apart a couple years ago that I would need to photograph it before hand.

 

[DougMF41]

I think I understand the problem now. I've been trying to get the rivets/bolts that go through the head to go through the spring and the knife bar. Your second photo shows that your head rivets only go through the spring. And your spring doesn't have rivets that go through it and the knife bar until you get around 8 out from the head. Can you verify that that is true? That would mean I need countersunk rivets at the beginning before using the bolt kit I got to finish out the rest. That's the first photo I've seen that makes sense out of this.

 

[FarmerJones]

The first section (small rectangular) has two rivets and overhangs the end of the knife bar by about an 1/8". What is the overall length of your spring?
There is no hole where your red dot is. Are there two rivets in your first small rectangular section?

 

[FarmerJones]

Bingo.
The spring fastens to the bar at the 6th hole from the small rectangular section, or the 8th hole from the end of the bar.
That is in the far hole from the small rectangular of the third full section.
The countersunk rivet is MF 364169X1. I bought mine at TSC. The parts list call for 7 each. Make sure you get the correct diameter.

It is called a spring because it allows for flex between the drive head and the knife bar.

It is a great mower when taken care of. Just grease the wobble gear faithfully. I use it for two small fields where it is difficult to maneuver the haybine and for along the banks of the stream.
Good Luck!

 

[DougMF41]

Thanks for your help! On hold until I can get to TSC. Is that first partial section supposed to be sharp? Mine's mostly worn out if so.

 

[FarmerJones]

(quoted from post at 14:24:39 04/25/21) Thanks for your help! On hold until I can get to TSC. Is that first partial section supposed to be sharp? Mine's mostly worn out if so.

Glad I could help.

It should have an edge. I just hit mine with a file.

 

[Phil Tibbetts]

Guess you don't need my pics as somebody has already sent some. Good luck with it I love my 41, best mower I've ever used.

 

[DougMF41]

I have a couple more questions (and there will probably be more). Should the section bar be flat from end to end or should there be a bow in it. Mine's probably a few inches higher on the ends than in the middle when it sits on the ground loose. Do you use a tool for the rivets or just hammer them in like the guys on youtube?

 

[FarmerJones]

I always use a rivet tool or the specialty threaded fasteners.

By section bar do you mean the knife bar or the cutter bar assembled with the knife bar. With the inner and outer shoes adjusted equally the cutter bar should lie level at the height you want. I usually set mine at 3" with a slight forward tilt. It could be higher or lower as the conditions require.

Do you have a manual? They are available from Agco.

 

[DougMF41]

(quoted from post at 18:06:05 04/26/21) I always use a rivet tool or the specialty threaded fasteners.

By section bar do you mean the knife bar or the cutter bar assembled with the knife bar. With the inner and outer shoes adjusted equally the cutter bar should lie level at the height you want. I usually set mine at 3" with a slight forward tilt. It could be higher or lower as the conditions require.

Do you have a manual? They are available from Agco.

I think the parts diagram calls it the back knife. It's the thin bar with the sections bolted/riveted to it. When I take just that bar with the sections on it, completely separate from the machine, and set it on the ground oriented like it would be after you attach it to the machine, it does not lay flat. It bows up at the ends. The big heavy bar on the machine looks pretty flat. I don't have a manual.

 

[FarmerJones]

The bar to which the sections are attached should lie flat or close to it. It is mild steel and can be bent.
If the bow is not too severe the knife clips should keep the knife bar flat and then the rock guards can then be adjusted for proper contact with the sections
A manual is a good investment. Available as either a hard copy or a download:

 

[DougMF41]

(quoted from post at 05:41:18 04/27/21) The bar to which the sections are attached should lie flat or close to it. It is mild steel and can be bent.
If the bow is not too severe the knife clips should keep the knife bar flat and then the rock guards can then be adjusted for proper contact with the sections
A manual is a good investment. Available as either a hard copy or a download:

The knife back is pretty flat now. It was bowed about 3-4 " up on the ends compared to the middle. That might explain why it had so many little aluminum shims. Is everything adjusted with shims and wear plates or can I bend the guards?