Mowing MF 31 Sickle Mower with Smoking Gearbox. Any diagnostic tips?

[The kid]

Here's an interesting link for the MF31
Table of Contents

 

[Bid]

Kid, this looks like the right tool for the job! Thanks.

 

[/pine]

What is up with the belt configuration on these MF sickle bars...? you rarely if ever see a picture of a 31 or 41 where the belt is positioned on the idlers the way it is shown in the manuals...just curious...

BTW I have MF41...

 

[Rayrla]

Here's an interesting link for the MF31
Table of Contents

Thanks for the link. I have owned my 31 for almost 20 years now. Great cutter. Use it for my roadside ditches and for cutting under my rows of pines.

 

[The kid]

Your problem really sounds like a internal bearing problem that is fixing to go to the crapper. That manual will help you reassemble the mower if you break it all the way down.

Sent via Ipad2

 

[Bid]

Kit, the non-contact thermometer worked great! The front connecting rod bearing was over 400 degrees and the other bearings were around 120-125 degreees. I pulled the crankshaft and sure enough the front bearing did not spin smoothly. It's the one on the left in the following photo.

Something that concerns me is the fact the two connecting rod bearings are not identical. The bad bearing is narrower than the other one.

According to the parts diagram both connecting rod bearings should be the same. Does this look funny to anyone?

 

[Sodo]

Yes they are identical. I found one place that had MF31 bearings but the small front shaft bearing was $76 so I used a 6205 which has some problems but can be made to work.

I bet the big rid bearings are either NLA or $125

 

[Coyote machine]

Kit, the non-contact thermometer worked great! The front connecting rod bearing was over 400 degrees and the other bearings were around 120-125 degreees. I pulled the crankshaft and sure enough the front bearing did not spin smoothly. It's the one on the left in the following photo.View attachment 376548

Something that concerns me is the fact the two connecting rod bearings are not identical. View attachment 376549 The bad bearing is narrower than the other one.

According to the parts diagram both connecting rod bearings should be the same. Does this look funny to anyone?

I couldn't find the parts diagram, can you link to it specifically, please?
The crankshaft journals show wear, obviously, but where are pics of the actual bearings for each journal? If you can show the outer journal's bearings, and the connecting rods end caps beside them, it would make it easier to determine if there is anything really funky about your setup.

 

[Sodo]

I bet the narrow rod bearing (non-original) has no grease hole. Or maybe it rotated such that the grease hole does not align with the fitting hole. I bet you can't get another original. I'd take that narrow one to a bearing shop & replace it.

If you can't get one with a grease hole you will have to grind a grease hole in the one you have. I have used a dremel with the cutoff saw for this. Grind until its so thin you can break thru with a pick. Then you haven't contaminated the bearing. You might test-grind the bad bearing first to learn how. Then you might grease it and run it (then go get a new one when you have time).

Take a closeup pic of the bearing with your phone so you can see its bearing spec numbers. I'm curious what bearing it is (in case I have to replace one).

 

[Bid]

Coyote, it appears Agco has shut down access to their parts diagrams unless you have a logon. Fortunately, I printed a copy of the MF 31 mower diagram before they locked it down. Attached is a copy. It shows both rod bearings as item 21, which is part number 833770M1.

Sodo, thanks for confirming both bearings should be identical. I thought something looked wrong. You are correct, the narrow bearing does not have a hole in it to allow grease to enter the bearing. I will take some close up pics of the bearings later today.