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Model 50 Distributor Sprocket Removal

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Model 50 Distributor Sprocket Removal

Posted by mike_haworth at June 08. 2017

Does anyone know where I can buy a puller to remove the sprocket that drives the distributor on a 1959 Model 50 ? Or, is there another way of breaking it away from the taper ?

 

I did think NOC may have such things for sale but, if they have, I can't locate them ?

 

Mike Haworth

Re: Model 50 Distributor Sprocket Removal

Posted by George Phillips at June 08. 2017
Without checking I thought the Model 50 was a single, Mike. Where doers the distributor come into it?

Re: Model 50 Distributor Sprocket Removal

Posted by john_evans1 at June 08. 2017

No need to buy one. Lay a bar or thick spanner inside the filming case.Use another spanner or stout screwdriver wedged under the sprocket and upon the wedge you have created.

A sharp tap with your palm will remove the sprocket.

 

As you will know,it is not really a distributor,more a points housing.

good luck.

Re: Model 50 Distributor Sprocket Removal

Posted by john_evans1 at June 08. 2017

Ps.If you mean the lower sprocket..my own m50 sprocket comes off using the same method.

If not,make up a flat bar.Drill two holes large enough  for two strong pieces of strong round bar bent at 90degree to pass behind the sprocket. ensure that the section passing through the holes in the bar are threaded.

Place over the shaft securing the sprocket and tighten each arm equally.This should draw off the sprocket.

Re: Model 50 Distributor Sprocket Removal

Posted by mike_haworth at June 09. 2017
Previously George Phillips wrote:
Without checking I thought the Model 50 was a single, Mike. Where doers the distributor come into it?
You are correct, it is a single so it's not actually distributing anything. However it looks externally like a distributor and it houses the contact breakers. I still have the same problem, can't get the sprocket off ! Mike

Re: Model 50 Distributor Sprocket Removal

Posted by mike_haworth at June 09. 2017

Previously john_evans1 wrote:

No need to buy one. Lay a bar or thick spanner inside the filming case.Use another spanner or stout screwdriver wedged under the sprocket and upon the wedge you have created.

A sharp tap with your palm will remove the sprocket.

 

As you will know,it is not really a distributor,more a points housing.

good luck.

This must be well and truly fixed ! Your suggested approach has achieved nothing.

As I've never seen one of these disassembled I'm unclear as to why there is a thread in the centre of the sprocket. Surely this should be a clean hole with the thread only being in the shaft to which the sprocket is attached ?

I've made up a spacer that fits behind the sprocket and rests against the casting. My idea being to replace the screw that locks the sprocket in place, screwing it almost home. Then I have tapped (the points housing unit being unclamped) the screw pushing the sprocket against my spacer. This doesn't release the sprocket from the taper. I guess I'm going to have to make up a puller although the way this thing is fixed it's going to have to be a substantial one !

Mike

 

 

 

 

 

Re: Model 50 Distributor Sprocket Removal

Posted by john_evans1 at June 09. 2017

I am sorry it has not worked. to be clear..you are talking of the distributor sprocket?

if so my initial post should work.Certainly my unit comes undone easily by this method.

I assume yours may be seized therefore judicious use of heat and/or penetrating fluid should help.

The sprocket is not keyed,unlike the lower item.There is a shallow taper..no thread internally. it is simply retained by a bolt and washer.

If very tight there is another method but not recommended as great care must be exercised. Slacken the retaining clamp for the distributor.Unscrew the securing bolt for the top sprocket..not fully.Back it out About four threads then tap the bolt gently until the sprocket moves on the taper..I do not recommend this method as if you get it wrong it is possible to damage the distributor and casing. this worked for me on my last m50 but is virtually what you have already tried.

Lucas 18 d1 units are not easy to find.

Re: Model 50 Distributor Sprocket Removal

Posted by George Phillips at June 09. 2017
"As I've never seen one of these disassembled I'm unclear as to why there is a thread in the centre of the sprocket." Why do you think there are threads inside the sprocket, Mike? Especially if you can't get it off. As it's on a gently tapered shaft (for timing adjustment) it should have a tapered smooth b. Have you tried a hot air blower on the sprocket? George

Re: Model 50 Distributor Sprocket Removal

Posted by George Phillips at June 09. 2017
Sorry! Smooth bore. G

Re: Model 50 Distributor Sprocket Removal

Posted by alan_osborn at June 09. 2017
Confused? IF you have the real distributor ie the 18D2 these have a parallel shaft with a pin. You knock the pin out with a drift (or bent nail) and it all comes apart. Now if you have a magneto then you are faced with a tapered shaft with an manual or Auto sprocket. So I would have thought that the 18D1 would also have a parallel shaft. So if it is a taper a la mag then this seems strange.

Re: Model 50 Distributor Sprocket Removal

Posted by steve_adkins at June 10. 2017

Greetings from South Australia, The singles guru Mike Pemberton’s video has an excellent method of sprocket removal, which has been successfully used many times. Loosen the 18D1 sprocket drive nut a turn or so, not much, apply pressure from behind the sprocket with a small pry bar; see an example figure one within enclosed .PDF. Put some pressure on the back of the sprocket via the pry bar and give the nut a sharp tap with a copper mallet, the sprocket should break taper easily. I have a 1961 Model 50 and during a long overdue restoration Mike’s method was used with no issues. My inlet camshaft drive sprocket to 18D1 point’s chain-drive was a very different matter. In the end I made a puller from piece of flat steel 3/8 (10mm) or thereabouts thick. Centre drilled and tapped; used a 10 diameter mm socket head screw, with a ground taper to ensure the puller centre screw would not burr or damage the camshaft threads. You could then drill at suitable locations on the flat bar (to match sprocket teeth), but I slotted mine to give some flexibility; see figure 2 onwards. ¼” Whitworth (or similar) hex set screws, ~ 1 ½”long were used and the set screw heads were tucked behind the sprocket once the chain is off. Placed bolts through puller plate and finger tightened the wing nuts (because I had some), however ordinary nuts would be fine. Hold puller carefully and tighten centre hex cap screw. Once good and tight, give the loosened nut (same as previous operation) a sharp tap with a copper mallet and that should do the trick. Otherwise some Loctite freeze n’ release spray may help but any heat should be used very carefully. My M-50 restoration story was published in a late 2015 RoadHolder, sorry not sure which edition but latter part of the year, which included some detailed pictures of the 18D1 reconditioning, this is not a difficult operation. Good luck.

Regards Steve

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Re: Model 50 Distributor Sprocket Removal

Posted by mike_haworth at June 12. 2017

Previously steve_adkins wrote:

Greetings from South Australia, The singles guru Mike Pemberton’s video has an excellent method of sprocket removal, which has been successfully used many times. Loosen the 18D1 sprocket drive nut a turn or so, not much, apply pressure from behind the sprocket with a small pry bar; see an example figure one within enclosed .PDF. Put some pressure on the back of the sprocket via the pry bar and give the nut a sharp tap with a copper mallet, the sprocket should break taper easily. I have a 1961 Model 50 and during a long overdue restoration Mike’s method was used with no issues. My inlet camshaft drive sprocket to 18D1 point’s chain-drive was a very different matter. In the end I made a puller from piece of flat steel 3/8 (10mm) or thereabouts thick. Centre drilled and tapped; used a 10 diameter mm socket head screw, with a ground taper to ensure the puller centre screw would not burr or damage the camshaft threads. You could then drill at suitable locations on the flat bar (to match sprocket teeth), but I slotted mine to give some flexibility; see figure 2 onwards. ¼” Whitworth (or similar) hex set screws, ~ 1 ½”long were used and the set screw heads were tucked behind the sprocket once the chain is off. Placed bolts through puller plate and finger tightened the wing nuts (because I had some), however ordinary nuts would be fine. Hold puller carefully and tighten centre hex cap screw. Once good and tight, give the loosened nut (same as previous operation) a sharp tap with a copper mallet and that should do the trick. Otherwise some Loctite freeze n’ release spray may help but any heat should be used very carefully. My M-50 restoration story was published in a late 2015 RoadHolder, sorry not sure which edition but latter part of the year, which included some detailed pictures of the 18D1 reconditioning, this is not a difficult operation. Good luck.

Regards Steve

Many thanks for your advice Steve. I have made up a puller but so far no success. With puller in position I've applied heat. Still no success. Currently it is being left overnight under tension. I am really at a loss. I am frightened to go much heavier with the various approaches in case I damage the distributor unit - I've been told I am unlikely to find a replacement.

All for now,

Mike

 

 

 

 

Re: Model 50 Distributor Sprocket Removal

Posted by Barry Carson. at June 12. 2017
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Re: Model 50 Distributor Sprocket Removal

Posted by Ian MacDougall at June 13. 2017

Hi Mike

I don't have a distributor model single but I guess the sprocket size and access must be similar to the magdyno models. For those I use a 1506 puller from Beta tools, see photo. A solidly made item which does the job for me. I bought mine from Andy Molnar but it looks as if you should be able to order on-line from Beta.

http://www.beta-tools.co.uk/

Ian McD

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Re: Model 50 Distributor Sprocket Removal

Posted by mike_haworth at June 15. 2017

Previously Ian MacDougall wrote:

Hi Mike

I don't have a distributor model single but I guess the sprocket size and access must be similar to the magdyno models. For those I use a 1506 puller from Beta tools, see photo. A solidly made item which does the job for me. I bought mine from Andy Molnar but it looks as if you should be able to order on-line from Beta.

http://www.beta-tools.co.uk/

Ian McD

Hi Ian,

Thanks for this. I've had a look at the puller you reference and it seems to be the correct size. I'll give it a go.

Mike

Re: Model 50 Distributor Sprocket Removal

Posted by steve_adkins at June 17. 2017

Hi Mike,

Not wishing to push products (and I have no affiliations to Henkel / Loctite) but this product works very well, I have successfully used this on rusty and clean but seized fasteners:

http://www.loctite.com.au/3320_AUE_HTML.htm?nodeid=8802649931777

Use the puller, place under tension apply product as per instructions and hopefully it will part. However if these components are under a lot of pressure keep yourself away, because potential shrapnel (puller / sprocket etc.) can be very nasty!

Good luck.

Rgds Steve

Re: Model 50 Distributor Sprocket Removal

Posted by Ian MacDougall at June 17. 2017

To minimise (but maybe not eliminate completely) shrapnel damage just slacken the sprocket nut rather than remove completely. That way at least one of the components is restrained.

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