AMC clutch fitting problem

Also check out these old Roadholder notes

Have you got any photos you can post? Especially of the bits.This may help somebody spot a no-no. The rear sprocket (output) shaft should have some clearance behind the clutch body. It is only a few mm at most. So possibly your jelly gaskets are an issue.

One of the problems with the AMC gearbox is the number of variations of parts that can fit inside it. You can certainly mix and match with gears and shafts from the earlier boxes. I do believe that there are about 5 different types of mainshaft that will fit these boxes.

Checkout the attachment. It is from an old Roadholder. There may be some similar info on this website in the Tech Section.

Hi Colin, I have had a similar problem with my model 50 clutch, I have just had the gearbox re-built by M.H and am very confident about the standard of the re-build, but when I fited the clutch basket (in my case a diaphram belt drive unit) and bolted it on to the shaft it tightend on to the shaft holding the rear chain sprocket, I had to relieve the back of the clutch center by about 1/2 mm or so to enable both shafts to rotate when fully tight, After doing this so far no more problems, the clearance between the back of the clutch, and the final drive output shaft must be very slight. Regards John

HI Colin, Iwould sugest you speak to a gearbox guru such as Mick Hemmings, before going much further,I feel sure he will point you in the right direction. He and his wife have always been more than helpfull to me.

Regards John.O

Well your all looking in the wrong place , the real problem lies in the Clutch Spider as it as to fit tight to the main shaft and if its worn then it moves further up the shaft and dose not fit right any more, the Main Shaft is made from harder steel then the spider , But I have seen Spiders with very soft steel to tell this you need a punch and see how far the punch mark goes into the steel if its a small mark its hard steel if its a deep mark its soft steel you need to hit the punch with a small engineers ball hammer , hope this helps some one out, Yours Anna J Dixon

Well done Colin, at least you didnt have to resort to a hammer and punch!! any problem solved mainly by yourself with a little help from others is good.

Regards John O

Hi Colin

From memory the centres of both my Norton clutches look like the one you had trouble with. But they work in the same way as you describe with the lip on the end pulling onto the end of the shaft. I have a '34 inter with upright box and a '51 ES2 with lay down box. So the spider you have could well be for an earlier Norton box.

I had to use a puller to get the clutches off first time round as they had seized into place. But when I was taking the clutch on and off my Inter to mess about changing gearbox sprockets it pulled off fairly easily.

Andy

Ihave now sorted the problem!

I found another clutch center (spider) and this does not have 'through' splines - it has, what appears to be, a pressed in washer at its outboard end. When fitted this bears on the end of the mainshaft and gives around 40 thou clearance to the sleeve gear. I swapped this for my original and now all looks to be fine. I took it out for a brief road-test and the gear-change is now slickand no more strange noises!

So, it looks as though the original spider is different in that it only has small 'burrs' on the outboard end of the 'male' part of the splines (see photo 9527 below).You can see the difference to the other center in photo 9532 and 9533.

Is it possible that my original spider was from a Burman clutch?

Thanks for all the useful suggestions received!

well its seems to me that you men are ashamed to admit and woman was right , its was the Spider after all, and you where looking in the wrong places come on hand up, Any way I am glad to help ! Yours Anna J

Hello to all above.

I appreciate this is an old post but after hours of searching for a similar problem to the the one I am having this seemed to be the closest to my issues with my bike.

I am nearing completion of the restoration of my first Norton. I have a Dominator 99 and the issue is with the clutch center. When removed from the gearbox it's works fine and we have all gears available.

I then fit the clutch center and tighten the center nut to 70 ft/lb and once a gear is selected the box locks and i cannot rotate the gears.

It would seem the clutch center pulls hard up against the sleeve gear which I think reading above is not correct.

The gearbox ,engine and frame have allways been together and all have matching numbers.

On my rebuild as the bike had been restored many years ago and the gearbox was working fine the bike has had a very easy life since i did not rebuild the box. The bike was just stripped cleaned and rebuilt. Since the problem I have had the gearbox apart checked and rebuilt again 're fitted the clutch and the problem is still there. Undo the center nut box is fine tighten up box is locked.

Could anyone shed any light on the issue or what to do next.

Many thanks in advance.

Vinny.

Hello to all above.

I appreciate this is an old post but after hours of searching for a similar problem to the the one I am having this seemed to be the closest to my issues with my bike.

I am nearing completion of the restoration of my first Norton. I have a Dominator 99 and the issue is with the clutch center. When removed from the gearbox it's works fine and we have all gears available.

I then fit the clutch center and tighten the center nut to 70 ft/lb and once a gear is selected the box locks and i cannot rotate the gears.

It would seem the clutch center pulls hard up against the sleeve gear which I think reading above is not correct.

The gearbox ,engine and frame have allways been together and all have matching numbers.

On my rebuild as the bike had been restored many years ago and the gearbox was working fine the bike has had a very easy life since i did not rebuild the box. The bike was just stripped cleaned and rebuilt. Since the problem I have had the gearbox apart checked and rebuilt again 're fitted the clutch and the problem is still there. Undo the center nut box is fine tighten up box is locked.

Could anyone shed any light on the issue or what to do next.

Many thanks in advance.

Vinny.

Hi Vinny, Rest assured you have identified ONE of the causes of lock up and difficulty in selecting neutral. I had a similar issue with my 60 99 which appeared to have orriginal components. I first noticed contact wear on the back of the spider and posted about it on this forum. Other very experienced members pooh poohed my reasoning and thought that contact here would make no difference to neutral selection.I have to agree its not easy to quantify. I ground about 20 thou off the spider and it made no difference as the spider just moved further up the shaft!. I then studdied photos of secondhand spiders on E Bay and the breakthrough came with a decent photo (thanks!) of RGM's sale of reject (slightly wobbly) spiders. These clearly showed a better spline stop as you have noted. A new spider and things were much improved. Gearchange quality also improved with attention to mainshaft and gear spline finish, drum bearing modification and equalising clutch spring lift. Yes Anna you know about it too. PS not sure that 70 foot lbs is needed,may have brought the problem on.PPS, if you want to be sure of clearance just fit the spider alone and check behind with a feeler guage. My change is now so light that now I'm not always sure where I am!.

Hello Robert

Thank you for your reply

From reading your experience, it would seem that I have the same problem.

Am I correct that you rectified the problem with a replacementspider?

Also, could you confirm that when the clutch centre is removed I should be able to see a shoulder or the end of the splineon the main shaft?At the momentI cannot see any physicalstop so the clutch centre just pulls up to the sleeve gear.I will try to attach a picture.

I researchedthe torque setting from the Haynes manual. Clutch centre nut 70 FT/LBS. I agree it does seem high. Do you know if it wouldhave been possible when tightening the nut on the other end of the main shart against the support bearing in the inner cover it may have pulled the shaft towards the gear change side of the bike pulling the shaft into the sleeve gear producing the problem?

The reason I suggestthis is the fact that the bike was working perfectly before the clutch was removed and then refitted.

I apologisefor asking more questions and do appreciate your help in this matter.

Regards

Vinny

Hi Vinny, replacing the spider with one that had a full register (a continious ring) solved that problem. The shaft (as I remember !) does not have a stop at the sleeve gear end. My orriginal spider would not stay put ,especialy after 70 foot lbs! .And the stop was getting mangled. A well fitting washer under the nut is also important. In the past the clutch would come off easily but when the spider internal stop got worn a proper puller was needed and this was a warning that things were out.Check the end of the shaft spline close to the thread ,if in good shape this should abutt the continious ring in the spider (I think!). I used 50 foot lbs and a little locktite.

Previously robert_tuck wrote:

Hi Vinny, replacing the spider with one that had a full register (a continious ring) solved that problem. The shaft (as I remember !) does not have a stop at the sleeve gear end. My orriginal spider would not stay put ,especialy after 70 foot lbs! .And the stop was getting mangled. A well fitting washer under the nut is also important. In the past the clutch would come off easily but when the spider internal stop got worn a proper puller was needed and this was a warning that things were out.Check the end of the shaft spline close to the thread ,if in good shape this should abutt the continious ring in the spider (I think!). I used 50 foot lbs and a little locktite.

Hi Robert

On close inspection of the clutch centre/spider, it would seem you were bang on.

I cannot see acontinuous ring / stop at the front just burrs of metal where perhaps one used to be.

It would seem that the spider is worn as you suggested in a previous post and the main shaft has pulled through the spider closing the 40 thou clearance required. Possibly as you suggested due to the 70 FT/LBS of pressure put on it by yours truly.

It would seem a new spider is required.

Thank you and all of the above for your advice .

Regards

Vinny

Put the spider in a lathe and take a skim off the back. It will only need a gnats off to give it a clearance. It won't put the chain line out by any significant amount.

Or buy a new spider.

As previous post 70 lbs is a bit excessive. Loctite is marvellous.

Paul

Previously vinny_tray wrote:

Previously robert_tuck wrote:

Hi Vinny, replacing the spider with one that had a full register (a continious ring) solved that problem. The shaft (as I remember !) does not have a stop at the sleeve gear end. My orriginal spider would not stay put ,especialy after 70 foot lbs! .And the stop was getting mangled. A well fitting washer under the nut is also important. In the past the clutch would come off easily but when the spider internal stop got worn a proper puller was needed and this was a warning that things were out.Check the end of the shaft spline close to the thread ,if in good shape this should abutt the continious ring in the spider (I think!). I used 50 foot lbs and a little locktite.

Hi Robert

On close inspection of the clutch centre/spider, it would seem you were bang on.

I cannot see acontinuous ring / stop at the front just burrs of metal where perhaps one used to be.

It would seem that the spider is worn as you suggested in a previous post and the main shaft has pulled through the spider closing the 40 thou clearance required. Possibly as you suggested due to the 70 FT/LBS of pressure put on it by yours truly.

It would seem a new spider is required.

Thank you and all of the above for your advice .

Regards

Vinny

If the spider is a bad design then taking metal off the back is not solving the problem,as the spider will move up the shaft . Check carefully when you buy the new one that it has a full circle stop. Some are poor quality. Get the suppliers agreement to a refund if you are not happy with the design ,before you buy it.

It is important to find out what exactly is causing the problem. Taking metal off the back of the spider may just move the chain line of the clutch inwards, and cause the primary chain to be mis-aligned, and the problem of contact between clutch centre and sleeve gear may still be present.

A friend had this problem, of the clutch centre and sleeve gear being in contact on his AMC 1 box. Note that this sleeve gear was extended and is much longer than a horizontal box sleeve gear. His chain line was correct, so he ground a small amount off the sleeve gear extended nose. That solved his problem.

While on the subject of AMC and Norton boxes, there are few actual parts in common, even tho' the AMC is closely derived from the Norton, and before it the Sturmey Archer. For example, the dogs on sleeve gear and matching mainshaft 3rd gear have a different number of teeth, and are closer inwards because there is no thrust washer in between, and no rollers inside the sleeve gear as before. The sleeve gear shaft is extended... Third gear is 21:21 instead of 22:20

Paul

I had the same problem on my ES2, a new spider from RGM sorted it, although getting the Cush rubbers in was a bit of a palaver!

Previously robert_tuck wrote:

If the spider is a bad design then taking metal off the back is not solving the problem,as the spider will move up the shaft . Check carefully when you buy the new one that it has a full circle stop. Some are poor quality. Get the suppliers agreement to a refund if you are not happy with the design ,before you buy it.

Thanks Robert

I think I will call RGM rather than purchase on line.

That way I can confirm it's exactly what I need.

Thanks again.

Vinny.

deleted . me brain wasnt in gear

The RGM one I bought is correct,as were the springs.