Hedgecutter noise from rotor

J

jack_c

Member

• Sep 6, 2017

• #1

A noise has come into the head on my new to me McConnel PA48e.

It has created a vibration too.

Was no issue yesterday and only appeared today, doesn't seem to be any play in the rotor either, and wasn't hit either.

Is it possible to upload a video on here?

 

Lincs Lass

Member

Location

north lincs

• Sep 6, 2017

• #2

Lost one of the hammers or the balance weight has come adrift

 

J

jack_c

Member

• Sep 6, 2017

• #3

http://s1118.photobucket.com/user/J...1-48D9-A389-5ECA9DD0F300_zps1lhwwsku.mp4.html

 

J

jack_c

Member

• Sep 6, 2017

• #4

How hot should the drive motor get?

 

J

jack_c

Member

• Sep 6, 2017

• #5

Lincs Lass said:

Lost one of the hammers or the balance weight has come adrift

Click to expand...

I don't think so, all seems to be intact

 

Lincs Lass

Member

Location

north lincs

• Sep 6, 2017

• #6

jack_c said:

I don't think so, all seems to be intact

Click to expand...

Check the end bearing ,,is it direct driven or is the motor mounted above with a belt drive

 

E

essexpete

Member

Location

Essex

• Sep 6, 2017

• #7

Most hydraulic systems get hot under working conditions but not exhaust pipe hot.
Sounds like a balance issue as LL mentioned. A slight bend in the rotor could be a cause as well.

 

A

agrimax

Member

Location

Co Down

• Sep 6, 2017

• #8

Check all the flail nuts are tight. Even one loose nut can make a difference.

 

J

jack_c

Member

• Sep 6, 2017

• #9

Done more investigation, head vibrates quite heavily, but as soon as it is taken out of gear the vibration stops even with the rotor still spinning fast

 

RLC

Member

Location

North Yorkshire

• Sep 6, 2017

• #10

Check all bearing and rotor mounting. Bolts.

 

J

jack_c

Member

• Sep 6, 2017

• #11

Will double check them, what I don't understand is that the vibration stops when motor disengaged but rotor still spinning at almost full RPM

 

E

essexpete

Member

Location

Essex

• Sep 6, 2017

• #12

Could be a bearing then?

 

hedger7050

Member

BASE UK Member

• Sep 6, 2017

• #13

Check all the nuts and bolts on the whole head especially the two either end holding the roller on and the 3 or 4 (depending what model) bolts that hold the rotor bearings on. These work loose and can make the noise and vibration. Also had the bolts that hold the front hood on do the same. Just because the nut is tight on the bolt don't assume there actually tight is if it's been vibrating it can wear the threads lower down on the bolt and make it impossible to tighten the nut down even more.

 

D

Directdebit

Member

• Sep 7, 2017

• #14

The way to check if it is bearings or rotor balancing is to run the head horizontal then vertically,if vibration stops it's more than likely bearings.

 

D

dickie-boy

Member

• Sep 7, 2017

• #15

have you tried varying the pto speed with the head engaged to see if you have the vibration at a slower driven speed

 

B

brynseiri

Member

Location

Conwy, North Wales

• Sep 7, 2017

• #16

Check the manual, you can tighten the bolts that attach the rotor bearing assembly with a breaker bar, however the motor bolts need torquing as per the book iirc. Bit of a PITA as you gotta remove the motor guard to get at them. Make sure you grease the bearings until the grease appears out of the carrier every day. As said, check the flail bolts regularly too.

 

Kevtherev

Member

✓

Location

Welshpool Powys

• Sep 10, 2017

• #17

Its either the head drive shaft splines a bent motor shaft or a bearing on way out.
Take the motor off and inspect the drive splines

 

J

jack_c

Member

• Sep 10, 2017

• #18

Took the rotor out and found play in the non drive side bearing, will get a set of bearings in and hopefully that will solve it.
I didn't realise that the bearing was shimmed to the head and 2 shims fell out when disassembling. I'm fairly sure I know which bolts they came from but not 100% sure, is there a way to know which require shims?
Silly mistake on my behalf.

 

J

jack_c

Member

• Sep 10, 2017

• #19

brynseiri said:

Check the manual, you can tighten the bolts that attach the rotor bearing assembly with a breaker bar, however the motor bolts need torquing as per the book iirc. Bit of a PITA as you gotta remove the motor guard to get at them. Make sure you grease the bearings until the grease appears out of the carrier every day. As said, check the flail bolts regularly too.

Click to expand...

Is it possible to get a manual online? The machine didn't come with a manual unfortunately.

 

J

jack_c

Member

• Sep 10, 2017

• #20

Directdebit said:

The way to check if it is bearings or rotor balancing is to run the head horizontal then vertically,if vibration stops it's more than likely bearings.

Click to expand...

This was something I meant to say in my original post, the vibration occurred when the head was vertical and not so much when horizontal.