Greasing a reluctant bearing

[Shane]

Hi folks,

This morning I've been servicing my Predator 450 stumpy.

 

Hit a problem with one of the cutter wheel bearings. Pillow-block type.

The grease nipple looked a bit knacked - the ball part of the nipple had disappered and it would not take any grease. The other side was fine and you could see the grease easing out of the bearing like always.

 

I took the 'good' nipple off and put it on the other side thinking that would solve it. But NO.... No matter how many pumps I could not get any grease in.

I checked the grease gun is still working (you can tell by the resistance anyway) and it is.

 

I've tried poking wire in but still no joy.

Apart from replacing the bearing (which is still OK at the moment) has anyone got any tricks that I can try?

[C.J]

Unbolt block,undo grub screws,slide of shaft,remove bearing insert and clean.

[Gary Prentice]

Hair dryer or hot air gun, old grease can harden and stop any more getting in. I've seen plant mechanics use blow torches, but assume they know there's nothing in the particular bearing to melt.

[Mountain man]

Ive had some success with petrol, try and get it in the hole, it liquifies the hard grease a bit.

[Shane]

Thanks for the replies, will try subtle heating and then petrol.

 

If all else fails then removal it is, I was just hoping for an easier solution if possible.

[Goaty]

You can get a greasing tool where you his it with a hammer and it blasts the nipple back into use. This is first one that came up in google. Ive never used one.Grease Fitting Unblocker

[Logan]

Hey Goaty, I bought something similar to that grease fitting unblocker in the states about a dozen years ago and had fair success with it for a long time, but having been hammered for a few accumulated hours the end that sits on the nipple don't seal too well and it's not so effective these days.

 

The other one is to try a 10,000psi low volume per stroke grease gun, rather than the normal 6,000psi standard grease gun. We use such a gun on several points that aren't blocked, just a little bit "tight".

 

Not tried heat before. Anyone had success with heat method?

[PeteB]

Rotate the bearing as you pump in the grease too.

[Shane]

Well, you live and learn....

I tried a bit of heat, petrol, greasing as hard as poss.. spinning the cutter wheel while doing each - nothing.

 

In the end I dropped the cutter wheel out and removed the complete bearing.

It was only then I realised the actual ball bearings are sealed and the grease is only for the contact surfaces of the outer casing and the pillow block housing.

 

After a soak in petrol and a few taps with a drift each way, I was able to get grease in - tomorrow its reassembly time!

 

Thanks again for all the help.

[GA Groundcare]

Pop the seals out and grease the bearing up. If you've soaked in petrol the bearing won't have much quality grease left to lubricate.