Hayter Harrier 2 drive problem

[Fix'em all 49]

Appreciate some advice on this if anyone can help. My dad uses on old 19" Harrier 2 & has lost the drive. The drive cable seems to actuate a lever that engages the drive. Need to get this apart but it's not that clear how this is done.

 

[Wristpin 400]

Does the cable go to a little lever on a shaft out of the left of the BS engine block?  If so, it has an internal  Power Trac wrap spring clutch - best described as a good idea at the time. Lots was written about them at the time but the outcome was the same!

A lot of machines were converted to the previous dog clutch system and quite a few were just dumped. If you are very lucky the problem could just be cable adjustment - make sure that the lever is being fully moved from stop to stop, but if it's not, the non availability of parts may scupper the job. I believe that the wrap springs are still available - I might even have one. There was a repair kit 394871 but fairly sure it is NLA. 

[Fix'em all 49]

I only had a quick look yesterday & the  outer casing of the clutch was red in colour. I seem to remember there is a hole for a grubscrew or roll pin (couldn't see which). Is this how it comes away from engine. Certainly when it was working the spring inside is quite strong as the handlebar lever  needs a bit of pulling. Does this help i n terms of identifying which type it is. Cheers, Ian

[Wristpin 400]

From what you are now saying it sounds as though you are looking at the plastic casing around the original external dog clutch assembly and if the “ no drive “ was sudden it is likely that the failure is either of the roll pin holding the drive half of the dog clutch to the APTO shaft , or the roll pin locking the bronze gear within the sump to the Auxilliary PTO shaft has sheared.

A quick test is to remove any covers so that you can observe the shaft where it exits the engine, engage the dog clutc and try to push the mower forward .  If the internal pin has failed the pto shaft will rotate freely allowing the machine to move. If not it will lock.

Replacing the internal pin may be done through the small removable plate in the engine sump but only if you can account for all the broken bits of pin, otherwise it’s a sump off job. 

As an aside to your issue , neither of the halves of the dog clutch are still available unless you can locate any New Old Stock. I’ve seen various attempts to “ dress” rounded off dogs to achieve more positive engagement - not many successful, so it’s important to preserve what you have by correct adjustment. A factor that defeats this is wear within the sump allowing excessive APTO shaft end float making correct adjustment impossible. Briggs answer to this was a new sump and bronze gear but we developed a solution using a 50p thrust washer from the Qualcast parts bin.

A proper investigation and , perhaps, an image or two will save a lot of guess work.

[Fix'em all 49]

Thanks Wristpin, no worn or broken parts in the end. It was all tight on the shaft and just needed grease