Over speeding a chipper /shredder?

[CalG]

I've used the MacKissic TPH185 3 point mounted chipper shredder for a number of years now.
I've sharpened the pair of knives maybe a half dozen time, replaced the anvil, and flipped the shredder flails to use all four corners. (I may need to build the set up with hard facing next go around)

But......A question...

Although the tool is designed to be run as a 540 rpm pto input, the darn thing seems to be much happier, and MUCH MORE productive when it's run at around 750-800 rpm input.
Both the Kubota B7200, and the Hurlimann 435 Prince provide the high speed output at normal to reduced engine rpms. (the B2601 does NOT)
The drive shaft doesn't seem to mind, And I haven't thrown a shredder flail in all these hours of use/
I do give the main bearings a pump of grease a couple of times each summer (when I think of it)
The machine does not seem to complain of the "abuse", in fact, there is much more material clogging and belt squealing when the input is restricted to 540 rpms.

What might be the down side of the higher operating speed?

I don't think MacKissick needs to be informed of this obvious excess! ;-)

 

[doneill127]

I have an older smaller MacKissac tp122 and the manual says it can operate at 1000 and 540 pto speeds.