Self-Propulsion issues on an Atco Balmoral 20SE

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Dazzlin
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Self-Propulsion issues on an Atco Balmoral 20SE

Afternoon all:

First post on a forum dedicated for Lawnmowers :)

Just picked up myself a Balmoral 20SE (Tecumseh engine model)... Before using it I did all the usual maintenance issues (Fresh oil, sparkplug and air filter)... Started like a dream, right on the button...

Here's my issue/concern related to the self propulsion though... On absolutely flat ground (concrete) the bugger will run away with you like a maniac, but put it on grass and, as if like a petulant child, self propulsion is --- well at best it's pathetic.... Certainly not like the advert you can still see on youtube (lets put it that way).

So I'm wondering.... New belt?

I can take a wee video to upload of whats happening if there's any experts in the house to give me a diagnosis.... 

Many thanks all

 

D

wristpin
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When you put it on grass and

When you put it on grass and engage both the cutting cylinder and the forward drive are both lacking in power. ?  If so I’d have a look at the coupling between the engine and the top shaft. Then do a visual inspection of the belts , do they look ok with a distinct V ?

Then engage each one in turn ( engine OFF) . Are they being pulled tight into the pulleys ? If they seem to be ok get someone to operate the machine while you walk beside it and observe what seems to be happening with the roller drive pulley. A dab of white paint or marker on the  pulley may help.

If all that seems ok the job may be more serious and involve dropping the rear roller out.

 

 

Dazzlin
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Thanks so much for the reply

Thanks so much for the reply @wristpin :)

OK, so - not gonna lie --- didn't get a chance to drive around and see what's going on.... What I did do was set up my phone to take a wee video of the gears all "in action" and I just held up the mower in the air (it was on flat concrete, so was quite happy to lunge forward!).

I recorded the video in "slow motion" so its easier to identify what's going on... Do you mind if I email it to you to have a look at? No expert - but to me it looks like the belt is just a bit flappy --- but I could be wrong :)

Thanks so much - your help is very much appreciated

Sincerely

 

D

 

wristpin
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I'm not sure whether you can

I'm not sure whether you can post a vid on the forum directly but I think that you can do it via youtube or Dropbox but I don't have an "ology" in such matters!

One test that may be useful is with the engine OFF and the machine on a grippy surface, engage the roller drive and try pulling the machine backwards. It should lock enough that it skids without rotating.    

 

Dazzlin
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Hi ---- thanks for the reply

Hi ---- thanks for the reply again

OK, here goes --- 

https://photos.app.goo.gl/fN9Oo1ex7790ahdF2

Sadly, it didn't go back to slow-motion - but you can see how tight things are ---- and options are very much welcome

Many thanks :)

 

 

D

wristpin
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It certainly looks as though

It certainly looks as though the belt is too slack to drive effectively. The options would seem to be - the pulley hidden behind the cylinder drive one has opened up and the belt has dropped into the V. Wrong belt, worn belt, incorrectly adjusted belt tensioning jockey pulley. 

When you engage the drive bar does the jockey pulley running on the back of the belt move at all and with the bar held in drive can the jockey be moved by to increase the tension? 

Dazzlin
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Thanks fella :)

Thanks fella :)

Right - Well heres my end of day results... I had a good go walking around with it this evening and what I found was that the wheel attached to the roller (connected with a thread bolt) slipped (slips?) an awful lot...

I removed the nut, and the wheel and just to make sure it wasn't slipping "any extra" I've used a couple of the securing nuts (not sure what they're called) --- but the little ribbed nuts that when you tighten them they grip on exceptionally well... So now I know that the wheel, connected to the bolt really is ultra-ultra connected... if that makes sense...

Anyways, took it on a walk about... It still has the same "problem" but then I started to wonder... "Should" the roller be able to be stopped and the wheel keep turning? Seems fair to say there must be some sort of gearing mechanism inside the roller because to just have it connected to the wheel "as if it were one" would cause untold problems perhaps...

So, now I'm starting to wonder if it is really is going "ok-ish" and if its just me expecting too much from it...

Late night rambling - but feedback on what to expect from the propulsion system is appreciated :)

Many thanks

 

wristpin
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In your video the large

In your video the large pulley appeared to be being driven in fits and starts - was that with the drive engaged?   That large pulley should not be relying on the tightness of its retaining nut to transmit drive as the hole in its centre should not be round but should have two flats to engage corresponding flats on the shaft that it drives. If the centre hole is round it will be slipping on the shaft. 

The other end of that shaft carries a pinion running in a reduction ring gear which in turn transmits the drive to the roller via a differential situated within the two roller sections. The early versions of that differential were known to come adrift from the shaft. 

 

wristpin
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I removed the nut, and the

I removed the nut, and the wheel and just to make sure it wasn't slipping "any extra" I've used a couple of the securing nuts (not sure what they're called) --- but the little ribbed nuts that when you tighten them they grip on exceptionally well... So now I know that the wheel, connected to the bolt really is ultra-ultra connected... if that makes sense...

Re- reading the above  - it doesn't make sense - to me!  A decent image may explain! 

Dazzlin
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Haha! I suspected it was late

Haha! I suspected it was late night ramblings... I'll get a picture of my weird nut "solution" and a wee video of what I now suspect is happening out before the day is done...

I'm now leaning towards the bearings inside the roller being more worn "than usual" - causing it to slip more than its supposed to - but we'll see :)

As always thanks for the help :)

 

D

wristpin
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Not sure what bearings you

Not sure what bearings you are referring to or what they would have to do with the perceived “slipping” of the drive . Basically you have a belt driving a pulley. The pulley driving a toothed pinion which drives a toothed ring gear and the two roller sections via toothed gear differential. That differential is bolted to its shaft and it has been known for that bolt to shear with loss of drive.

Bearing wear anywhere along that drive chain tends to result in roller locking when trying to push or pull the mower rather than loss of drive. A logical fault finding process is called for rather than stabbing in the dark.

 

Dazzlin
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Ah, ha!!!!

Ah, ha!!!!

Found the problem!

New pinion needed :)

 

wristpin
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Well, that would account for

Well, that would account for the issue. Be careful when shopping for a replacement as there have been two or three similar looking ones used on different machines. The current part number of yours is, I believe, F016102295 but check!

As it runs in conjunction with the roller ring gear it will be wise to check its condition and also they both are are running smoothly together and this is where bearing wear comes into the equation as if either component is not firmly supported the teeth of the pinion may not be running in full mesh with the ring gear and there will be accelerated wear.

A basic test is to remove the belt and push the machine back and forth to check that it is smooth running with no jamming.

It should be noted that when your design of chassis was introduced there were several issues concerning chassis flexing that was causing gear meshing and drive problems and there were several service bulletins on the subject. I would have thought that all the early machines would have been modified by now but it’s worth bearing in mind. I will post a summary of the bulletins later.

EDIT

Some of the bulletins issued to cover chassis and roller issues

https://www.dropbox.com/s/aeehg9ssysh03xg/Suffolk%20Qualcast%20QX%20issu...

 

Dazzlin
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Thanks for the help matey: I