Mowing Greasing Frequency MMM

[oldballs]

I've been mowing with Kubota CUT's with 5 ft MMM for 16 years now. I usually clean up (not grease) the MMM and the tractor after every usage. I'm getting older now and want to cut back on greasing if possible. Right now I grease about every 10 hours of mowing...that is about 3 mowings of the place. What frequency do you all shoot for.??

Cheers,
Mike

 

[edgarrian]

20hrs

 

[DarkBlack]

Once every blue moon should do.
My last company did biannual greasing on very hot motors running 24/7, and assemblies, and had longevity in the tens of years.
That’s a new greasing every 4,380 hours…

 

[sixdogs]

I grease my wheels every other use (2 acre lawn) and the spindles every five or six times. U joints are 10-ish ours and so is everything else.

 

[timbatrader]

it really depends on the bearing or bush I were always told by the bearing experts more high speed bearings were damaged by over greasing than under greasing but pins and bush's in mud or dusty conditions need regular greasing to maintain that dried up glob of grease that acts as the dust seal

 

[RjCorazza]

I shoot for every 40-50 hours on my zero turns (but never over 50). I have about 2000 hours each on the zero turns with no failures.

 

[Hay Dude]

I like every 25. Deck bearings are expensive failures.

 

[Lineman North Florida]

Grease is cheap , do it often and use more than a nickle's worth when you do.

 

[oldballs]

Thanks TBN'ers,,,,,,, looks like i'll be be safe to extend the MMM greasing to at least 20 hrs........belt spindels... and U-joints. The front Gage wheels are easy to get at.........but that duo rear center gauge wheel set is very difficult to get at....as well as the U-joints.

Mike

 

[Hay Dude]

Thanks TBN'ers,,,,,,, looks like i'll be be safe to extend the MMM greasing to at least 20 hrs........belt spindels... and U-joints. The front Gage wheels are easy to get at.........but that duo rear center gauge wheel set is very difficult to get at....as well as the U-joints.

Mike

The rear U-joints on the Kubota ZD mowers are awful to access.

 

[Runner]

it really depends on the bearing or bush I were always told by the bearing experts more high speed bearings were damaged by over greasing than under greasing

I've heard this before too, but other than maybe displacement of the seal, can't figure out what damage you could cause by "overgreasing" a bearing.

I would go by the manual. The manual for my RFM says grease everything every 9 hours, so every fourth mowing for me.

 

[JJT]

The rear U-joints on the Kubota ZD mowers are awful to access.

I put my Kubota ZD on my lift, lower the mower as low as it will go and the zerks are pretty easy to access. Without the lift - major pita.

 

[DarkBlack]

I've heard this before too, but other than maybe displacement of the seal, can't figure out what damage you could cause by "overgreasing" a bearing.

It’s true with ball and roller bearings. You can cause the rolling elements to slide between the races instead of rolling, and it can flat spot them and cause early failure.
Grease is good for over a thousand hours of use. Unless your seals are bad, and you’re loosing the grease, and/or ingesting dirt into the bearings, it makes no sense to grease every 20 hours. Better time and money would be spent fixing the leaky seals.
Remember, off the shelf sealed ball and roller bearings are spec’d to around 2,000 -10,000 hours, with just the original grease in them.
Plain bearings aren’t sealed as well, and will force out grease though, and do merit more periodic replenishment

 

[sixdogs]

Thanks TBN'ers,,,,,,, looks like i'll be be safe to extend the MMM greasing to at least 20 hrs........belt spindels... and U-joints. The front Gage wheels are easy to get at.........but that duo rear center gauge wheel set is very difficult to get at....as well as the U-joints.

Mike

Something interesting that I learned was that my B7800 with a MMM had small wheel bearings in the mower wheels. I thought it was just metal to metal. I learned this as I was selling it and had I known would have greased at 10 hours rather than every other time.

The spindles were greased more frequently as well, but longer or on schedule for the U joints and things under the mower. In fact, one of the reasons I sold it for a Grasshopper was to have more accessible grease fittings.

I've mowed since the '60's and never had any spindle, wheel or u-joint failure by using just a little more grease.

 

[Runner]

Grease is good for over a thousand hours of use. Unless your seals are bad, and you’re loosing the grease, and/or ingesting dirt into the bearings, it makes no sense to grease every 20 hours. Better time and money would be spent fixing the leaky seals.
Remember, off the shelf sealed ball and roller bearings are spec’d to around 2,000 -10,000 hours, with just the original grease in them.
Plain bearings aren’t sealed as well, and will force out grease though, and do merit more periodic replenishment

Logically, I agree with all that, but then, why does the mower manufacturer say grease it every 8 (24) hours?

Actually, double checked the manual - it says u-joints and wheel spindles every 8 hours, blade spindles 24 hours. Nevertheless, I've been greasing everything, every 9 hours for the last 18 years and no issues....

 

[DarkBlack]

Logically, I agree with all that, but then, why does the mower manufacturer say grease it every 8 (24) hours?

Actually, double checked the manual - it says u-joints and wheel spindles every 8 hours, blade spindles 24 hours. Nevertheless, I've been greasing everything, every 9 hours for the last 18 years and no issues....

I’m not familiar with your machine. It must use somewhat crude bearing sealing methods. Why else would you need to push out fresh 8 hours old grease? Good U-joints employ roller bearings and cup seals, and are good for over 1,000 hours.
How often do you change/add grease to your PTO shaft U-joints? Your vehicle’s driveshaft U-joints? Vehicle wheel bearings? Electric motor bearings?
I’m guessing your manufacturer wasn’t confident in their bearing seal design, to keep grease in and dirt out

 

[sixdogs]

Logically, I agree with all that, but then, why does the mower manufacturer say grease it every 8 (24) hours?

Actually, double checked the manual - it says u-joints and wheel spindles every 8 hours, blade spindles 24 hours. Nevertheless, I've been greasing everything, every 9 hours for the last 18 years and no issues....

Mower companies want to sell mowers and some people might choose one mower over another. They need competitive standards to survive.

Much the way most car makers all went to a 10,000 mile oil change interval. It's because others did. Most mechanics will say a 5,000 mile oil change if you want your car to last.

 

[DarkBlack]

Much the way most car makers all went to a 10,000 mile oil change interval. It's because others did. Most mechanics will say a 5,000 mile oil change if you want your car to last.

You don’t think the technology of engines, fuel , and motor oils, have improved?

 

[Runner]

I’m guessing your manufacturer wasn’t confident in their bearing seal design, to keep grease in and dirt out

Perhaps, but I don't think Woods is known for making poor quality equipment.

 

[DarkBlack]

Perhaps, but I don't think Woods is known for making poor quality equipment.

Not saying it’s poor quality. Just saying, that a quality grease is still “new” condition after 8 hours use. Your Woods implement must not retain it within adequate sealing methods, if it either leaks out so fast, or requires you to push out 8 hour old grease, because it’s contaminated with dirt? Again that’s a sealing issue.
I’m only talking of ball and roller bearing assemblies.
Plain sleeve bearings are the exception , like in your loader arms. No seals and grease gets displaced externally, so require frequent additional grease