Another swing arm silent bloc removal question...

[Fast 58 BSA]

Hello all,
My 58 GF Frame is stripped and off to be sandblasted along with various parts. Resto finally under way To get the swing arm off I had to resort to cutting the spindle with a hacksaw. Worked ok, albeit a bit nervewrecking...now I took the swing arm to my machinist as I am converting from full width to to qd rear set up. I discussed removal of the old silent bloc bushes with him and he said that he could press them out, no problem (we'll see about that...). Now, the question: is this possible? Or is there some lip inside the swingarm that will obstruct the extraction by means of a press? Best to make sure before he (potentially) destroys the swingarm...appreciate any help

[bsa-bill]

Some say no lip but there was on mine so looks like one of those variables although I would think a lip would be desirable in order to centre the bushes

[Fast 58 BSA]

Thnx for reply . I wonder if its safest to err on the side of caution, and resort to some other means of removing the old bushes than using a press...Reading through the posts on the forum there appears to be many different ways of tackling the job, all unfortunately involving quite a bit of blood, sweat & tears  .

[beezermacc]

Here's what I do, very effective, but might seem a bit brutal! Drill into the rubber of the silentbloc with a drill which is so big (can't remember the exact size, approximately 3/16") that it drills into the rubber and skims some metal from the outer and inner steel tubes. You are drilling parallel to the swing arm cross member along the length of the silentbloc. With a little bit of careful judgement you can select a drill which takes so much metal from the outer tube that the drill is virtually touching the metal of the swinging arm. Drill two or three holes like this with a drill which is as long as the outer tube of the silentbloc. Then burn the rubber out with a blow torch. The centre tube can be easily pulled out as the rubber softens, then the outer tube collapses along its length at the weak points created by the drill edge. This is by far the easiest method I have come across and actually not as difficult as it sounds..... but quite messy!

[bsa-bill]

Yes I'll go along with beezermacc , that's the method I use with the exception I drill enough rubber out that I don't need to do the torch bit

[BSA_54A10]

Similar method,
Get rid of the rubber & inner by your favourite method.
Originally I used a Dremel to cut through the outer then a screwdriver to collapse it into the tube and pull out.

Now I have access to a MIG so I tried the steering bearing method and it works quite well.
Do a run of weld along the outer for as far as you can.
As it cools it will contract and then it will fall out.

[KiwiGF]

I don't think they can be pressed out there's no lip inside to do that

Using one the methods above the inner tube can be removed thats the easy part .....then I knocked over the ends of the outer tube using a punch and hammered the outer tubes out using a bar inserted from the other side, had to knock the ends over sgain several times but I
got there in the end

Filthy job one gets covered in the remains of the rubber etc!

I'm one of the posters on this topic, make sure the replacement blocs are correct size there are duff blocs around

[Fast 58 BSA]

Ok, so I told the machinist I'll handle the job myself. He'll press out what remains of the hollow spindle and I'll give the bushes a go with the described method and report on progress. I've read other posts recommending C&D for the silent blocs. How do they compare to SRMs?

[beezermacc]

I remember writing some instructions for this job. They're on our club website Tech Tips page.  www.cheshirebsa.co.uk

[Fast 58 BSA]

Brilliant! Thanks

[bsa-bill]

C&D had bushes made by the original firm from original drawing I bought a set after trying to fit the duff type (bought from a BSA guru who should know better)
The C&D bushes fitted like dream

[RichardL]

C&D had bushes made by the original firm from original drawing I bought a set after trying to fit the duff type (bought from a BSA guru who should know better)
The C&D bushes fitted like dream

If I read Bill correctly, he is referring to some parts out there with slightly oversized ODs. If you end up with those, taking out the old ones will seem like a walk in the park compared to installing the new ones. There is an issue of having the correct interference fit, but I don't have the table available to me right now. Then, in my ignorance, I'm not sure if the interference fit should be tested with the bushes frozen or at ambient temperature. Help, somebody.

Richard L.

[bsa-bill]

those are the one Richard, got them so far in then they just crumple up - more than a bit annoying

[RichardL]

I honed-out the insde of the swingarm, then, expelled quarts of sweat drawing them in with a 3/4" threaded rod and nuts. Then, they didn't line-up perfectly, so I had to run a reamer through them to remove the overlap of the tube ends where they come together near the center. I don't think this increased the IDs where they meet the frame plates so I hope I am getting the correct fit to the spindle.

Assuring the correct fit is highly recommended. In my case, if it had to be done again, I would have to find the oversize type, due to the honing of the swingarm.

Richard L.

P.S. I know this appears to drift far Fast 58 BSA's story and into my own story, but I think it is a decent way to pass on the lessons from the experiences. I think I had to learn it all the hard way, with ignorance in the way.

[Fast 58 BSA]

Thanks for the good tips and suggestions. This forum is great . Manosound, sounds like you had quite a job inserting the new bushes. I take it they were not bought from C&D (which sounds like the ones I should be buying). ?