Hayter 48 - Rear drive roller issue

[H4rry]

Hi there,

If possible, looking for a bit of mechanical advice with a 2008 Hayter 48 Pro and an issue with the rear drive roller.

Background: My (very) old, inherited from my grandfather, Hayter 48 Pro sadly died a proper death recently, I think it threw a rod, not 100%, but sounded pretty terminal. Given its age, I decided to look for a new (second hand) model and found a 2008 48 Pro that had been professionally serviced with new parts looking all shiny.

I'm in no way having a moan at the purchase, it has covered 3 mows just perfectly, and continues to cut beautifully, apart from a newly developed issue with the rear drive roller. Just means it is bloody heavy to push.

In short, when you press the bar to engage the roller to move the mower forward, it turns, and tries to move the mower, but doesn't seem to have the power to drive it forwards. If I lift the back of the mower up, you can see the roller turning when engaged, then stops when disengaged, but put the mower back on the ground and it tries to move forwards, but just squeaks a bit and fails. Almost sounds a bit like a car cam-belt (but not quite).

I'm not overly mechanically minded, but don't mind a bit of investigative work, and happy to take a look, but struggling for initial information to help me diagnose what is going on, and last thing I wanted was to pull it to bits and someone say "oh yeah, that's quite common, it's the left phalange that's stuck and needs a bit of grease" lol.

If anyone has an idea, happy to listen to info. (I do have a video, but bit to big to upload here sadly)

Thanks muchly.

[Mick]

Hi H4rry, and welcome to TGMF.

Do you have the exact model number of the Harrier from the silver sticker on the deck of the machine?  If not a simple photo might be helpful.

[H4rry]

Thanks Mick, yes, got that:

Hayter Harrier 48 AutoDrive 490F

[Mick]

Thanks for that info, it helps a lot.

Ok your machine has two drive belts and that's probably where I would start looking.

To check this I suggest first remove the air filter, and then tip the machine on its side  (Air filter side down).   Pull the HT cap off the spark plug for safety, then remove the blade bolt and blade, and the blade disk.  You can then see if the belts are loose and slipping.

[H4rry]

Ah thanks so much Mick - I'll take a look after work this evening.

Not sure if this helps (or works!!) but I've shared a video of the issue hopefully being demonstrated (shared via my Microsoft OneDrive account):

https://twistedhaloltd-my.sharepoint.com/:v:/g/personal/dale_twistedhalo_co_uk/EV5PYoRichFJtsmHAkwtQDAB0zf3rjdutYIQ9kw77isq5A?nav=eyJyZWZlcnJhbEluZm8iOnsicmVmZXJyYWxBcHAiOiJPbmVEcml2ZUZvckJ1c2luZXNzIiwicmVmZXJyYWxBcHBQbGF0Zm9ybSI6IldlYiIsInJlZmVycmFsTW9kZSI6InZpZXciLCJyZWZlcnJhbFZpZXciOiJNeUZpbGVzTGlua0NvcHkifX0&e=bS2iCa

[Mick]

Thanks.  Definitely sounds like the belts slipping in your video, it could be the belts it usually is even when they look ok, or it could also be the variator pulley (the double pulley between the two belts) causing this. 

By the way you should not move the variable speed control (the red one) without the engine running. Does it make a difference to the drive if you move that control while drive engaged?

[H4rry]

By the way you should not move the variable speed control (the red one) without the engine running. Does it make a difference to the drive if you move that control while drive engaged?

Ahh, thanks Mick - did not know that - as soon as allowed outside I'll start it up, engage drive and adjust the variable speed control and report back.

[Mick]

Ahh, thanks Mick - did not know that - as soon as allowed outside I'll start it up, engage drive and adjust the variable speed control and report back.

No problem. The variator doesn't move easily when when no running so you can stress the cable etc, plus if the pulley is moved when stationary it can if it's a little worn or stiff lock itself in a position where one belt stays loose. You might be lucky and that's what's happened.  Running it with drive engaged and moving the lever fully from fast to slow and back again to fast can sometimes sort it.

[H4rry]

Thanks for all your advice Mick. So, the variator adjustment (with engine running and drive bar engaged) didn't make any difference - which lends me to believe I've probably buggered it myself by adjusting the variator when the drive bar isn't engaged, or worse, with the engine off.

I will still also take the time to eyeball the belts as well to be sure, but will turn attention now to the variator pulley.