BSA Owners' Club Forum

The BSA Workshop => Twins => Topic started by: briand2 on 04 March, 2018, 16:13:52

Title: clutch hub
Post by: briand2 on 04 March, 2018, 16:13:52
I have been struggling for over a day now trying to pull the clutch centre hub from the gearbox shaft of my four spring clutch A10, I have the proper extractor for it which I have now managed to strip the threads of. I've applied heat, tapping it whilst under pulling pressure but it won't budge a single thou. Anybody any ideas please?
Title: Re: clutch hub
Post by: Jackson on 04 March, 2018, 17:24:14
This won’t help, but I had to destroy the nut on my 6 spring hub. Drilled two holes at the edge of the nut and used a cold chisel. Replacement was only about £3.00 though.
Title: Re: clutch hub
Post by: RICHARD MILLS on 05 March, 2018, 17:53:21
Is it 42-3170 that you are trying to remove? I had trouble with removing that part on my 1958 B33 (alternator model). The part had been modified and didn't have enough thread left to enable the puller to engage enough without stripping the thread. Tried all sorts of things including heat and 3 legged pullers which would not fit firmly enough, but to no avail. Finally removed it when I remembered that I had a bearing separator (Machine Mart's item CHT253). Not sure if it was the large or the small separator that I used, but I do remember that I had to tighten it up quite firmly(!), and then whack the end of the thrust bolt; dramatic surrender as it shot off with a loud cracking noise! The B33 has an alloy chaincase and I loosened the fixings of the inner chaincase so that I could push the rear end inwards towards the gearbox sprocket to give enough clearance to fit the separator.
Hope this helps.
Title: Re: clutch hub
Post by: RICHARD MILLS on 05 March, 2018, 18:38:03
P.S. Bearing separators are much cheaper on eBay, not sure of their quality.
Title: Re: clutch hub
Post by: briand2 on 11 March, 2018, 10:54:44
Thanks Richard, I've tried everything exactly as you did, even with trying to pull it off by fitting a three pronged pull behind it, but as you found , I couldn't make it grip enough. I'm going to try boring our the inside of my clutch extractor to allow it to thread on a bit further. If that doesn't work I will look to getting the tool you mentioned.  :)
Title: Re: clutch hub
Post by: EDDIE SIMPSON on 11 March, 2018, 21:42:56
a 3 legged puller will work. the secret is to tightly wrap a chain and padlock  F.T. around the outside of the legs to stop them spreading when loaded.  a bar on the puller nut and BANG.
Title: Re: clutch hub
Post by: RICHARD MILLS on 12 March, 2018, 17:28:20
You will get there in the end! Please post saying how.
Have looked at my separator and it must have been the smaller one that I used.
Good luck.
Title: Re: clutch hub
Post by: Tridentnik on 13 March, 2018, 13:05:05
I am having the same problem with my B25 clutch hub at the moment. So far i have trashed the thread on two pullers (61-3583), both made by MCA. These do not seem to be of good quality at all these days. The thread seems to be very badly cut. I am now thinking of using a three legged puller and will let you know how I get on.
Title: Re: clutch hub
Post by: briand2 on 13 March, 2018, 13:32:52
Ya Hoo I've got it off at last, I went to see a marine engineer where I used to work and he lent me a splitter, a real heavy duty bit of's all about having the right tools. Thanks everybody for your comments and advice. On to the next potential problem lol.
Title: Re: clutch hub
Post by: Tridentnik on 14 March, 2018, 16:45:54
Congratulations! Following your success with your friend's bearing puller I bought one from Screw-fix. The jaws just about fit between back of the clutch hub and the inner chain case. At the first attempt nothing moved so I put the kettle on and checked I wasn't doing something wrong and then I tried again. Like before nothing happened, then as I turned away "BANG" the whole lot leapt six inches into the air landing on the floor. There was slight damage to the puller ( bent clamp bolt) but hey the hub was off and undamaged. I can thoroughly recommend the bearing puller (£19:95 from screw-fix). Lets hope that we have both experienced the "glitch" for this mission as they said in Apollo 13.
Title: Re: clutch hub
Post by: RICHARD MILLS on 14 March, 2018, 17:33:57
Well done to both of you!