Flail Mower 25A Eating Bearings

[frankydp]

Evening,

I have a late model 25A Flail.

Yesterday I got a vibration on the mower, go check underneath , and saw all three blades on the non-drive end of the drum missing.

Well I got those fixed and one other, started it back up, and almost immediately had a hard shake and after stopping the PTO the drum stopped immediately.

Needless to say the drive side bearing had failed. This is my second bearing failure in less than 2 years on maybe 12-20 hours a month of seasonal use.


Can anyone shed some light on the lifetime I should expect out of these bearings?
Do I have a bent drum?
Are missing blades just really that hard on the bearings?
Are there any aftermarket collars or bearings that are beefier?

Just not looking forward to this bearing replacement as the they always a hassle.

Any wisdom would be appreciated.

 

[leonz]

Hello Frankydp,

Flail Mower Rotor Bearings should be replaced in pairs any time you have a bearing failure. Follow the same rules for the rear roller as well.

Causing impact damage to a heavy 3 row flail mower rotor to create an imbalance like the one on the 25A takes a lot of abuse to damage it.
Anytime you change locking collars and bearings you want to drill small dimples where the set screws will dig in to the flail mower rotor stub for the drive pulley and the
opposing bearing.

Missing side slicer knives not replaced will raise havoc with a flail mower rotor if the opposing side slicer knives are not removed to balance the rotor or if the missing knives and hangers are not replaced.

Are the bearings mounted on this beautiful late model JD flail mower sealed or is one side sealed and the other open-which is the normal state of things.

The 25A flail mower rotor on your flail mower if yours is like my dads has 3 rows of side slicer knives

As far as bearings go Timken or FAG or Seal Master are of very high quality.

Its always a good idea to pump 5-6 shots of grease in each bearing before mowing for long periods or after mowing for 6 hours.

A bearing will fail if the V belts are to tight as well so keep that in mind.

You can purchase gates V belt tension gauges from amazon to assure you have the correct V belt tension.


Time for bed.

 

[frankydp]

Leonz, thanks for the insights.

I have sealed bearings.

So on my machine the bearing collar does not have a cuff on it, which seems like that is different than the drawings on JD.com.
I am considering ordering a new collar and drive support plate, in case the part on my flail is not actually a factory part.

I have the round bearing assembly with 6 bolt holes, not the square one with 4.

I did order parts direct from JD last time and they sent me these China made bearings that lasted less time than the previous set.

I do run side slicers, and I do use a tension gauge.

On a side note, I just pulled the decintegated bearing off, and it was EXTREMELY difficult even with antiseize on the shaft during last replacement. Ended up having to chill it with ice and it was still stiff all the way to the very end of the drive shaft.



What is the highest quality bearing replacement for a JD9275?

 

[leonz]

Hello frankdp,

SO, your 25A has the six bolt mounting flanges?

Its best to take the inner and outer flanges and bearing locks for both sides with you to the nearest Kaman Industrial Supply and
be sure to take the measurements for both stub shafts with you if you have a micrometer large enough to measure
the stub shaft or a digital caliper to measure it.

I will tell you that if you take to the Flail Mower Rotor and the bearing mounting flanges set screws and locks with you to the nearest KAMAN
office you will be treated like a god as they will know exactly what you have and what you need.

You just need to make sure that they know you need a roller bearing that will be spinning at 2,200RPM+- when
at work and you have a V belt as a final drive for the flail mower rotor AND the roller bearing that must be sealed on
one side.

I know its a lot, but I want you to succeed and not fail; the folks at KAMAN Industrial know what they are doing.

Kaman Industrial has five sales offices in Georgia- Kennasaw, Atlanta, Albany, Lagrange and Savanna.
They have a warehouse in Georgia as well.

About ball bearings brands, you will not go wrong with Timken, SKF, NSK or Seal Master bearings.
I am sincerely sorry that JD has skulked down to that level with junk sealed roller bearings.



Leon