Drum mower - free rotating saucer not rotating!

[PrueSarn]

Hi - I'm new here and hoping that someone out there has had experience of this issue and can offer some helpful advice (other than "buy a new one!).

I've got a PZ CM165 drum mower and one of the bottom saucers is stuck. It will move around 3" but that's it. On top of that, one of the Allen bolts that holds it on won't come off but I'm planning to weld an allen key onto it tomorrow to see if I can shift it. Assuming I can get the last bolt out, and assuming that I can then actually release the saucer, what would the likely cause of the saucer not rotating be? Worn bearing? Just rust? Something else?

I did have a quick trial to see if it would cut but the belts started to smoke and the belt housing got very hot but I'm not sure if this is because of the stuck saucer or something else. I've checked the belts and the tension on the belts but noticed that there was quite a bit of belt frass under the casing. They are new belts that were put on a couple of years back and haven't done any work. I've checked oil level and the state of the dog tooth gears/bevel gears and they all look fine. How do I know when the belts are at the right tension? I've got them so you can push them down about an inch. I did take the belts off and gave the pulleys a clean up with a wire brush and the pulleys looked straight (aside from having a bit of surface rust).

Any help/advice would be most welcome!

Thanks

 

[Dave W]

Do the drums turn freely?
The drums and saucers have no interaction so can’t affect one another.

The saucer is easy. The bearings will have got rusted up and need replacing.
Once you got the last bolt out you’ll need to drive some timber wedges between drum and saucer. It’ll be tight and only tasty way is being brutal.
once off there will be a hub held on with with circlip and 2 standard bearings to replace.

 

[steveR]

The bugger is getting the saucer back on.... Needs a couple of extra long bolts to locate it and partially pull it up on the bolt threads, then put the fitting allen bolts to take it up tight.

 

[steveR]

The bugger is getting the saucer back on.... Needs a couple of extra long bolts to locate it and partially pull it up on the bolt threads, then put the fitting allen bolts to take it up tight.

Pretty certain I made a device to ease the job, but it's a long tiome since I had to do one!!

Probs in the mower parts box in the workshop!

 

[Bald n Grumpy]

The way to get the Allen bolts out of a saucer is to beat the hell out of them with a hammer and shock them before you try undoing them

 

[steveR]

The way to get the Allen bolts out of a saucer is to beat the hell out of them with a hammer and shock them before you try undoing them

I wonder if an impact wrench would shift them...? I used to use a manual impact driver. Tighten one thump, then anti clockwise.

Or, BFO allen wrench, put steady pressure on and then thump the bejasus

 

[Bald n Grumpy]

I wonder if an impact wrench would shift them...? I used to use a manual impact driver. Tighten one thump, then anti clockwise.

Or, BFO allen wrench, put steady pressure on and then thump the bejasus

Never had access to technical equipment, just a BFO hammer
Have used this technique on PZ and fahr

 

[David1968]

An inch movement on the belts seems a lot. I think they would stand a bit tighter.

That said, they should still turn the mower ok when it's not under load. So there's definitely a problem somewhere else.

 

[PrueSarn]

Thanks everyone. My attempt at welding a hex socket into the bolt didn't work and the bolt has rounded off so am off to Screwfix tomorrow to pick up an extractor set and give that a go. I've given the nut a bit of a pounding with a sledge hammer so hopefully that will encourage it out. The other two nuts came out sweet as anything, and I took the saucer off the other drum so I could compare, and they came off no trouble at all, which is typical! Not looking forward to putting them back on but I managed it somehow the last time as I'd had to replace one of the blade holders.

Both drums turn fine and the other drum's saucer is working as it should. The belts did get the drum's turning but I noticed that one seemed to have more give in it than the others. I've swapped them about and they all seem to now have even tension.

I've got an impact driver somewhere and pretty certain I've got the hex bits for it as well, so I'll give that a go as well but as the bolt is rounded in places, it may not succeed. Fingers crossed for the extractor kit...

 

[Dave W]

Don’t faff about with stud extractors. Waste of time.
Get a bigger nut and weld it to the stud then queen in water. Soon be out

 

[J 1177]

I wonder if an impact wrench would shift them...? I used to use a manual impact driver. Tighten one thump, then anti clockwise.

Or, BFO allen wrench, put steady pressure on and then thump the bejasus

Tried that one drum shifted the lot. Other one i had to weld nuts on

 

[pycoed]

Thanks everyone. My attempt at welding a hex socket into the bolt didn't work and the bolt has rounded off so am off to Screwfix tomorrow to pick up an extractor set and give that a go. I've given the nut a bit of a pounding with a sledge hammer so hopefully that will encourage it out. The other two nuts came out sweet as anything, and I took the saucer off the other drum so I could compare, and they came off no trouble at all, which is typical! Not looking forward to putting them back on but I managed it somehow the last time as I'd had to replace one of the blade holders.

Both drums turn fine and the other drum's saucer is working as it should. The belts did get the drum's turning but I noticed that one seemed to have more give in it than the others. I've swapped them about and they all seem to now have even tension.

I've got an impact driver somewhere and pretty certain I've got the hex bits for it as well, so I'll give that a go as well but as the bolt is rounded in places, it may not succeed. Fingers crossed for the extractor kit...

Don't use screw extracters (especially tat ones from Screwfix) it'll end in tears. Keep trying with the welder - have a look at IC Weld on Youtube. Now that bloke can really weld, & sometimes even he has mutiple tries before a bolt will shift. Heat will do it.

 

[High Major]

I had the same problem getting the screw out on a Fahr 22, used a bolt chamfered to fit in hex and a decent weld either side with 2.5mm rods. Squirt on some WD 40 when it still hot, allow to cool slightly and more wd40 and they unscrewed no problem. As it was a sunday afternoon and I wanted to get on put them back in and ground off bolts. Finished the 20 acres and replaced later. HM

 

[Binc]

if you haven't already, being upside down will make it much easier (the mower that is)

 

[PrueSarn]

Managed to get the bolt out (combination of drilling it out and then fitting a larger torx socket and using the impact wrench to get it out), but now, despite considerable hammering and positioning of wedges, the saucer is refusing to drop. Have given up for now and will make up a couple more wedges in the morning. Would it be worth trying with one of those log splitter "grenades"? Or any other ideas for getting it to budge?

 

[steveR]

Managed to get the bolt out (combination of drilling it out and then fitting a larger torx socket and using the impact wrench to get it out), but now, despite considerable hammering and positioning of wedges, the saucer is refusing to drop. Have given up for now and will make up a couple more wedges in the morning. Would it be worth trying with one of those log splitter "grenades"? Or any other ideas for getting it to budge?

Go mowing for 10 mins on the basis it is rusted solid, and it'll probably drop off!

 

[thesilentone]

Managed to get the bolt out (combination of drilling it out and then fitting a larger torx socket and using the impact wrench to get it out), but now, despite considerable hammering and positioning of wedges, the saucer is refusing to drop. Have given up for now and will make up a couple more wedges in the morning. Would it be worth trying with one of those log splitter "grenades"? Or any other ideas for getting it to budge?

You will need 3 decent width wedges, and a decent size sledge hammer. Keep going round them and don't stand in front of the saucer. It sounds well and truly rusted.

 

[bobk]

You will need 3 decent width wedges, and a decent size sledge hammer. Keep going round them and don't stand in front of the saucer. It sounds well and truly rusted.

This ^^ wedge it tight them whack the middle of the dish , prepare to be wearing it afterwards

 

[PrueSarn]

Thanks. The other saucer slipped off as soon as I removed the last nut. It's got 4 wooden wedges in already so I'll attempt a couple more, aim the sledgehammer at it and stand well back...

 

[thesilentone]

Thanks. The other saucer slipped off as soon as I removed the last nut. It's got 4 wooden wedges in already so I'll attempt a couple more, aim the sledgehammer at it and stand well back...

As the bearing was in such poor condition, whatever caused it (either water inside the saucer, or the mower standing in water) has also seized the shaft to the bearing. Some heat in the centre of the saucer on the outside would help, but I've never seen one that wouldn't come off with a little extra persuasion.