Hello there everyone. Some more advice required I'm afraid. I want to take the rear of the primary chaincase off but first I need to remove the four spring clutch adaptor that is on the gearbox shaft. Simple. Or so I thought. It appears to be keyed on to the gearbox shaft but a combination of heat and a puller have failed to move it. I can see some threads on the inside of the adaptor but I don't really think it is threaded on to the gearbox shaft. I have come to a stop through lack of ideas at the moment. Any help will be welcome. Regards. Dave.
The hub is a taper fit to the gearbox mainshaft.
Did you use the correct puller that is screwed in the threaded portion of the clutch hub ? That is what the threads on the inside of the adapter are for.
Normally, when the puller tool is installed and under tension, a tap with a hammer on the central bolt will release the clutch hub.
btw, there are two different types of pullers, as I found out the hard way, the earlier type has fine thread, (25tpi), and the later type has a more course thread (20tpi)
Peter R, I don't suppose you would know offhand if the 58 DBD 34 gearbox is old style or new style thread form?
To the best of my knowledge the goldie would have had a 6 spring clutch originally, so the 4 spring is a retro fit
To check which threads the centre has (if you do not have a thread gauge)
Use one of the primary case screws (1/4 x 20) and compare it to the threads in the centre?
then compare using one of the fine pitch 26 tpi bolts or screws on the bike, (rear wheel adjuster??)
The clutch centre nut needs to be really tight (65 ftlbs)when you replace the clutch
I had the same problem. First I tried the puller. There were only a few threads in the clutch adapter and they stripped the threads on the puller.
Then I tried a normal 2-legged puller. It bent.
Eventually I had to destroy the sliding plate, so that I could remove the gearbox and take it to a machine shop.
They used a lot of heat and a puller that slided between the clutch adaptor and the nut for the sprocket. Then it came off with a bang :-)
Yes, those threads on the inside of the adaptor were playing on my mind but I used a normal two legged puller and heat. All I achieved was to bend the flange on the adaptor. A new one is on its way. Obviously I still have to remove the old one. Can anyone tell me who may stock the correct puller and I will try my luck with the proper equipment. The adaptor is really tight on the shaft so I may have the same problem as you Ole. At least the adaptor is now scrap so if any more damage is caused to it, it no longer matters. Amazing how an hours job runs into days. Partly,I accept, because of my ignorance. Never mind. It's character building. Isn't it?
plenty of heat is your friend here. been through it myself. good luck
Most BSA parts dealers sell the correct 4 spring adapter puller. Don't ruin expensive parts trying to slide by without the proper tools. I can't believe using heat is necessary as I've removed these clutches numerous times. And yes as the gent previously advised, rap the head of the bolt after tightening the puller and it will release from the tapered shaft with a bang.
In my experience as I have both pullers, the 4 spring clutch puller has 'fine' threads and the 3 spring clutch adapter puller has 'coarse' threads.
"Normally" the adaptor will pop off if you use "shock heat"
Make sure the extractor is threaded fully into the adaptor and tighten up the centre bolt, then pour boiling water over the assembly, this will expand the adaptor rapidly usually enough to loosen it
Sometimes a previous owner has loctited on the adaptor
Then a gas torch will soften the loctite but can often damage the hardening of the adaptor ??
I have resorted to applying a rattle gun to the extractor bolt at times !!!!
On 4 and 6 spring clutch sleeves/adapters I had good success with a bearingflange type puller which fit behind the flange on the adapter/sleeve so pressure was applied all the way around. Snug it down very firmly, apply shock heat, tap the end of the shaft (nut on) and it should pop off.
You can remove the clutch on a Triumph or a BSA, the type that is held on by a key and a taper without any special tools. The Goldstar has this type of clutch attachment as do Triumph 650s and 500s.
You don't even have to take the clutch apart. Just take of the pressure plate, then un do the nut that holds the clutch on. The nut should be left on the shaft, but loose.
Then get a big screwdriver or flat bar that you can pry the clutch out a bit against the inner primary case. Then while you are pulling the clutch out, you have to hit the end of the shaft to release the taper.
I have never owned one of the clutch tools and have done it this way since Ken the mechanic who worked for years at British Motorcycles on Fraser St. in Vancouver explained it to me. That must have been in about 1981. I can't remember how many times I have used this trick.
This type of taper is used on many types of mechanical devices and often they can be removed quite easily by using shock. (tie rod ends, drill chucks, flywheels on lawnmowers) are examples of this type of fastening. Often without using the shock they are almost impossible to remove even with the correct puller. I use exactly the same method to take the flywheel off a lawnmower.
If the clutch centre has been put on with an impact gun, the clutch adaptor will be very difficult to remove.
Don't use a cheap e-bay puller- the metal isn't in it and the threads will strip.
I've had to weld the puller tool to the adaptor after stripping the threads in combination with heat, shock and all of the above methods.
eventually it came off with a combination of welded puller, heat and shock.
The adaptor was barely recoverable and I bought a new one.
The repaired adaptor was donated to a mate for his M20.
The material of the original adaptor is very hard and brittle and required a good number of small welds between the puller and itself- otherwise joint will break at the point of the welds removing material from the adaptor.
The clutch does not need to be that tight- use a large spanner or a socket by hand!
Puller now ordered so will update on success or failure. There's optimism. Thank you all for your replies.
The advice given above about screwing the puller all the way in is critical. Of course any washers still in the hub that will reduce the threads available. I measure the amount of threads in the hub and then figure out how much of the puller should be showing after the puller is fully threaded in. If the threads are poor you will need to work a bit to get the puller fully engaged. It you just stop when it gets a bit stiff you might not be far enough in.
The sharp rap once you get tension with the centre bolt is the key. Do not try to release the clutch by continuing to tighten the centre bolt past where you are applying tension.
I have never needed to use heat.
Bear in mind the 'tightened with a hand wrench' method is the reason there are so many galled/chipped BSA tranny mainshafts out and about as prolly the owner/mech didn't use a proper deep socket.
But of course those soft and poorly designed clutch nuts used with the POS @#$% 6 spring clutch were part of the issue with the nut coming loose. I hope everyone is aware BSA used a much improved nut/washer design when they fit the 4 spring clutch to the late model ('62?) A10s and Goldies. The p/ns are listed in the A10 parts book. BTW, this nut/washer combo should also be used when a belt drive primary is fitted.
As I've mentioned a couple of times earlier, the Tony Hayward clutch adapter with the larger diameter thrust face and thrust washer is by far better than the BSA designed adapter that will wear into the back side of the chainwheel.
BTW, the Hayward adapter requires using a 'coarse thread' puller as used with the later model 3 spring clutch.
Success. The correct puller arrived this morning and the clutch adaptor is now off. It is the fine thread type by the way. Anyway, it worked okay without even applying heat. All I need now is a new adaptor. Going off dave-NV I'll try Tony Hayward first I think. Once again, thanks for all your replies. Dave.
Here's a link to a new adapter. Not mine (just sold a couple of new ones for less!). Have dealt very successfully with the seller though.http://www.ebay.com/itm/BSA-A7-A10-...321643662112?&_trksid=p2056016.l4276
Thanks for the information Kerry. I tried Tony Hayward but he has none in stock. I also tried SRM engineering who also have none but apparently are awaiting for a new batch to be delivered soon. Supposedly these are superior to the originals as described by dave-NV above.
In the thread above, I read that you bought the puller with the fine thread.
I hope I don't spoil the party, but the Hayward/SRM clutch adapters have the course thread for the pulling tool.
Yeah,I realise that Peter but I needed to remove the original adaptor which I had damaged. The person I spoke to at SRM said the adaptors with the fine thread were original BSA items giving me the impression that all other adaptors have coarse threads. I don't know if this is so but I now have a only used once puller that is probably no further use to me. When I eventually obtain a new adaptor I'm already resigned to it probably having coarse threads but hope it will be some time before I ever need to remove it. Regards. Dave.
A lot (most) of the clutch adaptors on the market are made to the A10 spec and sold as fitting the B series as well. Yes they will fit, you find your primary chain out of alignment by up to 60 thou. This because the depth of the taper is machined to a different depth for the A10 crank posistion so it's front sprocket alignment to the clutch basket is correct.
Now, those Goldie dealers in the know and sell a complete clutch kit will have their adaptors re-machined from A10 to B series so that your clutch kit will fit and line up with very little shimming or on the crank.
I know this because because i have been to certain shed of a certain GS Guru and seen the process.
I hope that makes sense!
Hiya Mike. I think that makes sense. However, I am happy with the clutch I have so how can I know I am getting the correct adaptor before I buy one and check its dimensions. I suppose I can ask but can everyone be trusted?
Go to one of the UK GS guys and see if they have one for sale, mentioning that you hear there are differences in offset for singles or twins. Phil Pearson, Autocycle and others.
Hi, Don't take my word for it check this eBay seller a well know seller of Gold Star quality parts.http://www.ebay.co.uk/itm/BSA-A7-A1...orcycle_Parts_13&hash=item20ea35ef85
Now if you do a search for "baa clutch adaptor", you will find that many sellers sell the same item for both 'a' and 'b' series.!!
I fitted the A10 type (all that is on the market) to my mate's Gold star, measured the offset of the primary chain and them sent the adaptor to Phil Pearson who machined it for a small fee.
You may get away with the A10 type, as i have another GS by shimming out bearing the sleeve bearing (max 90 thou). This then may bring the crank nut into the outer casing, 2 ways to deal with this.
1. Fit an SRM crank nut and turn it down a bit and fit 2 gaskets on the primary covers and remove some material from the inside of the primary cover.
2. Make a spacer / disc to go between the crankcase and the inner chain case, effectively moving the outer chain case out.
have used both this methods
3. Instead of shimming the bearing sleeve, shim the front engine sprocket out only, you will need to get a proper hardened shim washed otherwise it will get hammered.
I hope this helps.
Thanks Kerry and Mike. A great help