60 MMM belt?

[Tdog]

I was mowing yesterday when I began to smell rubber burning, looked down & see bluish smoke coming up from the mower deck. I checked to confirm that nothing had jammed a blade or pulley. Also found the blades & belt could be moved by hand. I was puzzled, so I took the deck off. That's always a task I hate, but this time it only took maybe 5".
Turns out the belt is a double 'v' [there's probably a name for this type of belt]. Somehow the belt jumped down into the lower groove on the right pullley, so that the upper pulley groove was empty, the belt's upper 'v' was in the lower pulley groove, & the bottom of the belt was free. The blades ran fine with this arrangement, & I doubt I would have noticed it if the bottom of the belt hadn't been rubbing on something & heating up.
Anyone else had this happen? What is the cause? Debris on top of the deck?

I haven't put the deck back on yet. I finished mowing with my wife's Kenmore. What a downer.

Thanks,

Jack

 

[Dusty]

If your deck is loaded with debris, then that could have made the belt jump, or it could just be that the belt is old and tired. New belts are about $80 from memory, so I would try to get as much life out of this old one as I could. You can't do any damage to the deck using an old belt, so you have nothing to loose. Just make sure that there are no spindles that are going bad. Many of the decks were never properly lubed at the factory and the selling dealers didn't lube the spindles either. That made for dry spindles until the owners filled them with grease. I remember hearing about this a few years ago, but don't remember where.

 

[CampMan]

You are correct on the dry spindles. I had to give about 40-50 pumps on each spindle grease fitting before grease was seen.

 

[Spudgunner]

Slight topic drift, but I think I read somewhere on this forum that you can get a non-Kubota branded belt, such as a Gates, for the MMM's. Don't know what the Gates p/n is, however. If you don't have a Kubota dealer closeby, this might help in a pinch.

 

[don716]

I have reciently acquired a used kubota MMM for my tractor and was wondering ,How often should you grease the fittings?

Donny

 

[Tdog]

There was a thread on TBN about dry spindles some time ago. Mine was in need of grease then. However, I've kept it lubed pretty well since.

Don, owner's manual says to hit the fittings every 10 hours of use.

Still wondering if anyone else has experienced the belt 'shifting' in the pulley?

Jack

 

[Dusty]

I have reciently acquired a used kubota MMM for my tractor and was wondering ,How often should you grease the fittings?

Donny

You should remove the blades and the lower spindle grease cups and pump fresh grease into the spindles until all the old grease is pushed out. I suggest that you use a high quality high speed bearing grease. It will cost more initially, but in the end, you will save money not having to replace bearings or shafts. The factory original grease is green. After you have satisfied yourself that all the bearings are properly lubed, then reinstall the blades and properly torque them down. One trick that I have used is to mark the nut and shaft with a felt tipped magic marker and when I put the nut back on, I just torque it to the mark that I made. It is also a good time to clean the bottom side of the deck and sharpen the blades if they need it. If the blades are worn or have any cracks in them, replace the entire set. They are not that expensive and safety always comes first. There are also a few grease fittings on the top side of the deck other than the spindles. Don't forget to give them a squirt. Once every 10 hours or so, give everything another squirt of grease and wipe down the deck. Once you get used to doing this, you will save yourself a lot of time and money in unneeded repairs. While you have the deck off, it would also be good time to check and / or replace the gear box lubricant. Once again, don't skimp on quality lubrication. Clean all surfaces and give it a coat of wax and happy mowing.

 

[ByronBob]

How's the tensioner on your deck. The tensioner should keep it from jumping.

 

[rosey]

Might be time for a new belt.....noticed that you have over 700 hrs on your BX.......is the belt the original???

 

[Tdog]

thanks, all. Still not sure what the problem was/is. I think the tension is OK, at least it seemed pretty tight when I released the tension to move the belt back into place.
Yeah, I've got a few hours on the BX. Not sure how many are on the mower, however. Most of my hours are FEL & BH work. The bottom edge of the belt does feel a little rough, but I think that's where it was rubbing on the deck when it was running out of its grooves.
I haven't used it since I took it off - - guess I check it out in the next few days. For now, without anything else to blame it on, it must have been the cussedness of nature.

Jack