Broken Lawnmower Spindle

[Stellacerv]

Hello,

I need some advice please. Doing lawnmower maintenance.

The end of the spindle sheared off where the locknut goes. It is still inside the nut the lost bit is the width of the nut. There is nothing left to hold the tufnol washer in place and clutch assembly.



I have this threaded rod which has ever so slightly larger diameter 10.7mm. Can this be joined onto the old spindle? I have a blow torch and a bit of silver solder left over from the last job. Then it would mean drilling through the middle to allow the 5mm push rod clearance. The washer is 3.5mm thick and that is all that is left of the old threaded part.



The last time I was here I learnt about silver soldering repairing a blow torch. Unfortunatley I have no welding experience except soldering. Any information/advice would be much appreciated. I have been watching some of the welding videos on the forum recently as was thinking of buying a welder for doing repairs. Certainly finding challenges but you can learn new things and that is the fun.

Regards,

 

[MoreWellie]

Not sure which bits turn with the engine and which bits stay still, could you tap a thread on to the remaining small shaft and use a smaller nut combined with a washer

If that isn't practical I would have thought buying a replacement for the existing threaded bit might be a reasonable solution

 

[Brad93]

Hello,

I need some advice please. Doing lawnmower maintenance.

The end of the spindle sheared off where the locknut goes. It is still inside the nut the lost bit is the width of the nut. There is nothing left to hold the tufnol washer in place and clutch assembly.



I have this threaded rod which has ever so slightly larger diameter 10.7mm. Can this be joined onto the old spindle? I have a blow torch and a bit of silver solder left over from the last job. Then it would mean drilling through the middle to allow the 5mm push rod clearance. The washer is 3.5mm thick and that is all that is left of the old threaded part.



The last time I was here I learnt about silver soldering repairing a blow torch. Unfortunatley I have no welding experience except soldering. Any information/advice would be much appreciated. I have been watching some of the welding videos on the forum recently as was thinking of buying a welder for doing repairs. Certainly finding challenges but you can learn new things and that is the fun.

Regards,

View attachment 280854 View attachment 280855 View attachment 280860

Bore the spindle out and thread the rod in with permanent loctite

 

[minimutly]

I gave up on those things years ago, nice finish with them though.

 

[Stellacerv]

Not sure which bits turn with the engine and which bits stay still, could you tap a thread on to the remaining small shaft and use a smaller nut combined with a washer

If that isn't practical I would have thought buying a replacement for the existing threaded bit might be a reasonable solution

The whole part stays still. then the crankdrive goes behind the washer and is connected by chain to the drive and the roller.

Yes there is a 3.5mm stub left so with a thin washer and nut this would be a solution thanks. I have got a basic tap & die set.

The push rod which runs through the centre is operated from a lever on the handle which stops the traction of the mower forward motion.

 

[Stellacerv]

Bore the spindle out and thread the rod in with permanent loctite

The spindle is 13mm diamater so this would be possible solution too thanks

 

[Stellacerv]

Bore the spindle out and thread the rod in with permanent loctite

View attachment 281012
Bored the hole and tapped 10mm thread on. Need something to go inside hole now. 20mm long that will allow the 5mm push rod to pass through the centre. Is there a ready made machined part to do this please. You know I'm not used to making my own metal parts yet but I suppose I could do if I had some hollow tube.

 

[Stellacerv]

If I could have tapped a 10 x 1 thread through the spindle a brake union would have fitted perfectly. But I did a 10 x 1.5 as I hadn't thought of this way until later. There is no way I can use it now.

 

[Brad93]

Can you draw what you need? I could probably turn something up?

 

[Stellacerv]

Do you see that brake pipe union in the above picture? I'm going to try and find one in a M10 x 1.5mm size first. Thanks

 

[Stellacerv]

Can you draw what you need? I could probably turn something up?

Please ignore that last reply as it seems like nonsense today.

We'll see now if a few millimetres purchase is enough to hold the force of operating the clutch. My fear is that my repair will be somehow inadequate compared to the original machining but it may be unfounded. It's only a lawnmower but I didn't drill too far into the spindle (8mm) in case it weakened it. So it's held in by a few threads.

Have put a hole through the centre of the threaded rod, starting with a tiny drill and increasing in size.

It was too big and taking most of the outside of the rod with it at some point so I had to reassess it.

Also reassembled without the loctite and now regretting that I've got to take it to pieces again.