Help with lawn mower repair? (removing pins)

gerdalt

I have an Aeriens lawn mower.
The two main bearings on the hex transmission shaft (wheel drive) are shot.
New ones in the post.
The shaft has two pins in it to retain it in place.
How do I remove these pins?
They are of the 'fold' type - like a hollow cylinder with a slit down the side.
Initial thought is a blunt instrument - but the support frame is relatively fragile.
Is there a better/recommended way to get these type of pins out?
Or is it a hammer and punch job?
Thanks
Ger

Alun

Is there enough of the pin sticking out to be able to grab with a pair of pliers or pincers? If so, you might be able to pull it out. With pincers you'd be able to get a bit of leverage which would help.

If not then try and find something about the same diameter, or slightly less, as the hole, such as a nail (with the point filed/ground off) or a thin bolt and try and knock it through with a hammer. Sometimes these things have a kind of splayed end on one end, presumably to stop them falling out, so make sure you knock it out from the other end.

If all else fails drill it out if you can get access.

gerdalt

Thanks Alun.
There is a bit sticking out at each end.
Hard to see if one end is bigger than the other!
Are these pins tapered?
Ger

charlesD

This picture shows the splayed end that Alun was talking about. I would recommend replacing the pin, so wouldn't worry too much about how you take it out as long as you don't damage the lawnmower.

http://www.driv-lok.com/images/springpins.jpg

martinr5232

Hammer and punch just dont go mad couple of little taps of the hammer and just make sure to support the opposite end of the shaft with a block of timber.

gerdalt

Alun, Charles, Martin,
Thank you for that - especially the picture.
Will attack it tomorrow and report back
Ger

gerdalt

Good news!! A punch and some hammer taps easily removed the inner pin.
It is neither splayed nor tapered. Just a tight fit.
The hex shaft slid out easily.
But not the bearings!! They look a lot more stubborn.
Since they are shot anyway I can be less delicate with them.
Any suggestions appreciated.
Ger

martinr5232

Post a picture or PM me and ill give you my email and you can send one if you cant upload it on here.

gerdalt

martinr5232 wrote: »

Post a picture or PM me and ill give you my email and you can send one if you cant upload it on here.

Thanks Martin, will upload a photo here.
But day off today, so will be later this evening or tomorrow.
Ger.

gerdalt

Some progress but still a problem.
I have managed to remove the centre portion of one bearing. Only the outer casing remains. Photo attached.
Any suggestions on how to get it out? (tried lots of WD40)
Plan B is to dismantle the whole structure and be left on the bench with just the casting and the problem bearings. Looks like that's the only course.
The second bearing is at the back and I can probably tap/hammer it from the front inside and drive it out.
Such an approach is not possible with the first bearing. No access.
Maybe heat?
Ger

martinr5232

Its hard to make out from that picture where the bearing is I take it its the outer race that is stuck in the hole in the centre of the picture.

If so it should just tap out if you get a chisel and put the point behind the race with the shaft resting against the opposite end of the bearing race and tap the top side of the chisel on the side working your way around the race.

Be very carefull using hammer and chisels on bearings because they are made from hardend steel and will shatter so wear goggles.

Nonmonotonic

Martin has given good advice here.

Can you apply heat with blowlamp/heatgun? The heat may break the seal between the casing and the metal body of the mower. The different metals should expand at different rates. Try heat and a twist of a grip wrench. Tapping it all round might also loosen it as per Martins advice. You could deliberately shatter it but that is a dangerous and unpredictable option.

gerdalt

Finally got the old bearings off. New ones now installed and all is well.
Thank you to all for the various suggestions.
I was afraid of heat as I had no way to know the expansion rates of the two metals. The bearing case is steel but the frame is some sort of light aluminium type metal. I was concerned that the bearing casing would expand and shatter the frame.
I took the long approach and removed all the surrounding gadgets.
I was finally able to get a drift at the back of the bearing casing.
Half a dozen gentle taps and out it came.
When the front bearing was out I could then get at the back of the rear bearing and tap it free also.
Putting the new bearings in place wasn't easy. Lots of gentle taps and then some harder taps and then . . .
They are in place now!!

I HATE BEARINGS

Ger