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Hi all,
I am changing the wheel bearings on my 3 1/2 sport (cast wheel) and found that the rear ones don't have a circlip. I looked in my manual and there is nothing about wheel bearing removal. I don't want to start hammering away at them with out knowing if there is a threaded boss or other retention system that I hadn't seen.
Can anyone shine a little light on this for me.
Cheers
Andy

I've changed my wheel bearings last year-I just re-checked the rear wheel and I can safely state that there is a circlip visible on the left hand side,in my case covered in fine swarf descending in an irritating fashion from my rear disc brake. I used stainless sealed bearings in a bid to overcome the questionable weather sealing of the wheel bearings and a big expanding masonry bolt to knock them out with a warmed hub and a very cold new bearing.

Mine is a drum braked model. Anyone able to shed a little light?

I got mine out on a drum braked cast wheel sport about 3 weeks ago . Came out very easy cant remember if circlip was present but the spacer seems to fit insde the lip of the bearings not bwehind it. just be careful you should be ok. look on NLMs site at the parts book diagram for information.

You need a mandrel to push the bearing spacer out without damaging the thin end. The bearings are in effect sleeved down to suit the spindle.

I've seen many a mashed up spacer!

Thanks for that. I will look on the NLM site for the diagram. I have just broken my front wheel trying to get the bearings out. I had it in the press with blocks under the hub. The bike has been sat in a garden for 15 years or so. The bearings just wouldn't move(I did take the cir clip out). In the end the hub smashed and I wasn't using a huge amount of pressure. These wheels must be real delicate.

Have you got a picture of what you were trying to do?

Each bearing is pressed in with the outer race sitting on a shoulder. There is a spacer between the inner races and to get the bearings out, you have to push the spacer to one side so you can get a drift to the inner race. My trick is to use a rawlbolt to grip the spacer/inner race and drive them out together. When you've done one, the other side is easy to drive out. As always with an alloy housing, heat is a great help.

andyroach wrote: In the end the hub smashed and I wasn't using a huge amount of pressure. These wheels must be real delicate.

Ow. Drum brake, I assume? I have a spare single disc spoke hub that's surplus to my needs...

Penetrating oil can help too. I've found nothing works better than a 50/50 mix of atf and acetone, an old machinist's formula. The key is the acetone, I think pretty much any oil mixed with it will seep into anything.


Sam

Thanks Sam but I have another front wheel and will be going very caeful with that. No press and a lot of patience. But back to work again for the week so it will have to wait till the weekend.
Andy

EVguru wrote:You need a mandrel to push the bearing spacer out without damaging the thin end. The bearings are in effect sleeved down to suit the spindle.

I've seen many a mashed up spacer!

Do you have the dimensions of the mandrell?I have a lathe so will be able to turn one up.
Cheers
Andy

andyroach wrote:Do you have the dimensions of the mandrell?I have a lathe so will be able to turn one up.
Cheers
Andy

I don't know the dimensions, I just took a couple of quick measurements and machined something up. Took about five minutes.

CheersPaul,
I will get on it now.
Andy

Ok guys. I now have the wheel bearings out .Thanks for all your help. I will post the bearing sizes along with a diagram of the rear wheel mandrel at : motositaliana.wordpress.com
If anyone else is taking wheel bearings out or in fact any bearings out of a morini could they please let me know the reference number, model of bike, year and any info they think might be relivent.
I hope to get as many bearing sizes, special tool diagrams and general info on this blog for use by all and sundry.
Thanks again for all the advice.
Andy

I used stainless steel and sealed 6303 for the rear wheel bearings. As previously posted by Paul
Front;
Bearing No. 6203
Dimensions 17mm ID 40mm OD 12mm wide

Rear;
Bearing No. 6303
Dimensions 17mm ID 47mm OD 14mm wide
Sprocket carrier;
Bearing No. 6004
Dimensions 20mm ID 42mm OD 12mm wide

Thanks for that John