Has anyone had experience of removing the drive side needle roller bearing on a later B25? Problem is, unlike the Twins, it is an open ended bearing in a blind hole. There is a small clearance beyond it but without knocking up some very thin puller legs I cant see a way to get it out.
To be honest, I've taken a Dremel to a number of driver side needle bearings before now which is messy at best. I'll pop down and have a look at the blind bearing pullers I've got but, as said, I'm not sure whether there would be sufficient clearance at the end of the blind hole for it. An alternative might be to force out the rollers and then see whether the puller can grip the RH inner lip on the bearing.
Just checked and found I had previously ground the feet on my blind bearing puller down to 1.7 mm which is basically the clearance required to hook then under the LH end of the bearing. I wouldn't want to go much thinner smaller than this.
Sometimes we removed blind hole bushes by packing the hole with grease and offering up a dummy shaft.
Then thumping it with a hammer.
Hydraulic pressure pushed it out
Just looked into how other people have removed these needle bearings:
1. Using a Dremel (my usual approach)
2. Hydraulic as described
3. Tig welding bearing rim onto layshaft diameter rod inserted into the bearing
4. Drilling small hole through gearbox from LHS and then using punch through hole to drift out bearing
5. Use of oval headed bolt inserted at an angle into bearing after needles removed to fit behind RH rim to allow bearing to be pulled out
Therefore, it's a question of paying your money and making your choice! If BSA had engineered it correctly with maintenance in mind, it would have been possible to use a standard blind bearing puller but that was never in BSA's nature >:(
Hi, yes I have removed this bearing. I cut the lip of the bearing so that I could remove the needles. I then fashioned something that looked like a small armed grappling hooks (out of an old wire coat hanger) so that as I pushed it in the arms sprang open so I could pull on the parts of the lip I have not damaged. I think I may have heated the casing, but cant remember. I still have the removal "tool" in my tool box and old bearing case (see photos)
Kevin
I definitely think it's a question of trying whatever comes to hand to remove this troublesome needle bearing. I presume in this case, you pulled it out by hand?
The 3 x legs on my blind bearing puller could also be used to pull on the RH lip but the concern was whether the lip would be strong enough. As listed above, the use of an oval headed 'bolt' would work in the same way but provide a much greater contact area with the lip reducing the likelihood of it fracturing which is the problem other people have had. However, the amount of difficulty will also depend on how tight the bearing is in the engine casing which may well vary between bikes.
Yes I pulled it out by hand but what you can't see from the picture is that I made loops in the wire through which I could slip a bar in order to get a firm grip.
Kevin
Nine times out of ten a blind bearing extractor (if it is in good condition, the slide-hammer type) will pull out the needle roller intact. Less successfully as the four expanding "claws" get worn.
Occasionally the bearing is very tight in the casing so the extractor will not grip tightly enough to pull it out. The dremmel is the usual solution then - break off the outer lip, remove the needles and grind through the bearing outer just enough so it can be persuaded to collapse inwards.
I watched a video the other day where a guy pushed bread into the bearing to fill it up then used a piece of round bar to punch it in. Worked a treat.
I abandoned the punch and hydraulic action (bread, grease or whatever medium) method the second time it blew the back out of the bearing housing while doing it. The thickness of metal there varies due to manufacturing tolerances of the casting being variable. It can be less than 1/8" thick, which ain't strong.
The last time I got bearings out of a blind hole, though not on a B25 or any kind of BSA, was to put the casing (bearing pointing downwards) in an oven set to maximum temperature and have a cup of tea. When I heard two "donks" I knew my bearings were out. My new bearings had been in the freezer all night wrapped in plastic; they went in easily once I'd finished my tea.