Our Hayter Harrier 41 is regularly serviced by me and has had new belts for both the cutter drive and the gearbox drive.  If the Varispeed control is advanced to anything more than a slow walking pace the machine makes a loud rattling noise as if something is striking the frame/deck.  I have removed/dismantled/cleaned the pulley Variator assembly [411001] but this has made no difference.  I did note that the pulley sections did not slide very easily on the splined shaft.

I would be grateful for any guidance as it will only be a few weeks before the Head Gardener needs the grass to be cut again!!

Jim

Hi Jim, and welcome to TGMF.

Both belts are actually for the drive.    Things to check.

Make sure you have each belt in the correct position, the shorter one should go from variator rearwards to the gearbox, and the longer one from variator to engine pulley.  If they are the wrong way around the pulley will rub on the deck.

Make sure the left hand aluminium roller bracket isn't broken (Very Common) on these machines, You can usually tell if the bracket is broken because the front of the machine will bounce up and down quite a lot just by gently pushing down on it. And they usually lose drive.

The Variator pulley itself.  The centre sections should slide up and down freely to work properly. Also make sure you have the shouldered washer located properly in the back of the variator arm, and just a large washer against the head of the bolt.

Feel free to ask further questions.

     

Good afternoon Mick,

Thank you for your prompt reply to my enquiry and for correcting my muddled description of the drive belts!

It's too cold and dark to venture into the garage tonight but I will check all of the matters you have suggested and will give feedback to the forum in due course.

Jim

Quote from: Jimbo1 on January 10, 2024, 06:09:55 PMGood afternoon Mick,

Thank you for your prompt reply to my enquiry and for correcting my muddled description of the drive belts!

It's too cold and dark to venture into the garage tonight but I will check all of the matters you have suggested and will give feedback to the forum in due course.

Jim

No problem Jim.  Hopefully we'll narrow down the issue in time for grass cutting to commence. Keep us posted with your findings.

Good Afternoon Mick,

Thank you for your earlier advice, and I am pleased to report success with the repair to our Hayter machine by replacing the Variator assembly.  It is a bit of a fiddle to get at, and even with the underdeck cover and the left hand wheel cover removed it still requires fingers like 'Twizzle', but there was no doubt when the old part was removed that one half of the pully system was very stiff on the splined shaft whereas on the replacement assembly everything moved smoothly.  While everything was in pieces I treated it to a couple of new belts as well, and when the machine was fired up the Varispeed control now goes from 'Hare' to 'Tortoise' with no more rattling sounds.

I know this is mainly a do-it-yourself forum, but I have to say thank you to the staff at Crewkerne Horticulture who kindly confirmed the diagnosis of the problem from my description.  They are presently very busy so I purchased genuine Hayter parts on-line and did the job myself at the weekend.

Jim

Glad you got it fixed. I agree though they are a bit awkward and fiddley to work on, especially if you haven't done it before. I remember the first time I had to replace a variator pulley not long after that particular model came out. 

But they do get easier when you've done a few hundred of them.