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Hup 20 - what goes between clutch and actuator?


1912Minerva

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Hi All,

After getting my Hup 20 running I tried to drive it but found the motor was slowing and stalling when I pushed my foot on the clutch. On taking the motor and gearbox out and separating them, I can see the problem: the ring that presses onto the clutch to disengage it (first pic) has nothing between it and the clutch. As it presses on the clutch it is just slowing and stalling the motor. I have purchased a Torrington needle roller bearing of the right ID and Ok OD and associated thrust washers for either side but I'm not sure if this is the best solution. There is a groove on the drum which houses the clutch spring (see black arrow on 2nd pic) so am wondering what originally should be here? I have read about 2 bronze discs and a fibre disc on this forum - are they for this spot? If so, where can I source them?

As always, any help would be much appreciated!

Regards,

Andrew.

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G,day Huppers. Andrew, I do not like the rust pits on the withdrawal plate. this plate needs to be quite smooth. Originally there was a large washer of red fibre between this and the withdrawal face of the clutch. This was loose when not being used to put your foot pressure onto the clutch and in time it wore the groove that you mention. Red fibre is not long lasting here. We used a disc that we turned up from 1/4 in hard, thick aluminium . We turned down the thickness so we have a locating flange that keeps the washer running true with the hinged plate. Some folk use a needle roller bearing here but the speed the tiny rollers are doing concerns me. The two bronze plates with the red fibre between them are between the clutch and the machined face at the rear of the barrel crankcase. We were able to set the crankcase in the lathe and face off this face which was badly worn. We screwed the bronze first plate to the crankcase with 3/16 th brass screws then we used a red fibre disc between the 2nd bronze plate which we secured to the clutch. After a year of running the red fibre had almost disappeared so we took a further bronze disc and coated both sides with babbit and machined it to fit. No trouble since. Some folk use a needle roller race here also. As the main bearings are not able to take the clutch thrust from your foot then this is the bearing that does the work because the clutch is a slip fit on the crankshaft keys. There is enough friction here that it will slow the car when slowly changing direction or inching into a parking spot on the clutch. Those who have used needle rollers here say they have eliminated this feature. Max Burke Nulkaba 2325 Australia

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Hi Max and Ken,

Thanks for the replies. I pulled the clutch drum off (didn't realise it comes off so easily) and my car has no thrust washers between here and the crankcase so this was also part of the problem. Ken - Is there anyone who supplies the parts you show pics of?

Regards,

Andrew.

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Not that I know of .Most any machine shop should be able.

If you can't find the red fibre material,I would ask around about some of the durable plastics.

I would not recommend using a needle roller bearing for the big clutch thrust washer,the bronze will work o.k.I do like the idea of one between the clutch drum and engine,but the three shown will work fine.

Of course you will want to check the other bushings in the case while it's out.

the best,Ken

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G,day Huppers. Andrew take a look at the rear main bearing brass in the crankcase. Note that it stops about 1/8 inch from the back . The first bronze washer has a step or flange if you like that fits neatly into this space and locates it. I would not use red fibre as it will wear away far too quickly . The material that fibre timing gears are made from is available in round bar form. People that make these gears should part you off a disc and it is long lasting. Don't forget to align the punch marks on the main bearing of the clutch and the crankshaft . Punch mark may be on the end of the key. This clutch assembly was made to fit one way. If not in alignment the crankshaft will try to self align which is not good for it although some owners have purposely put the clutch on wrong to tighten the drive keys. While its apart check that the flange on the crankcase that the first bronze plate bears upon is still there, if worn away dressing up will need to be done and a thicker bronze plate made. The end float is adjusted by shimming the thrust buttons or by moving the back gearbox bush (bearing)Max Burke Nulkaba 2325 Australia

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G,day again. I forgot to mention that if you are having trouble with the bronze washers then any small foundry should/would cast a round of phosper bronze Pb1 and you can machine it up to suit your need. Yes we did find a clutch withdrawal washer of bronze. No doubt this was the original material. Perhaps the red fibre examples that we encountered were someones makeshift when the bronze was not available. Max Burke Nulkaba 2325 Australia

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The original parts book does mention pn 208 as being Fibre.

It also mentions one bronze is shouldered as Max noted to fit towards the engine,the other bronze is filleted or radiused a bit to fit towards the clutch drum.

I also see your clutch is not safety wired. You may also want to check the bushing at the front end inside there.

Of course use caution if you decide to open the clutch drum.

The material Max mentioned sounds good,I was also thinking of delrin or some such material.

the best,Ken

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Thanks again Ken and Max,

I have found someone who will machine up some washers from phosphor bronze for me. I can probably work it our from pics posted on this forum but can anyone supply approximate thicknesses for each of the washers?

Ken - I gather the fillets or radius you mention are grooves from the centre of the washer to the outer edge to pick up oil and lubricate it? I will safety wire the clutch drum before reassembly. The bushes seem ok - probably because the car hasn't done any real running yet.

Here are some pics of the back of my crank case where the clutch drum fits on:

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There are some slivers of metal there that I think I should remove to give the first washer a smoother surface. I take it that this is where the step/shoulder/flange on the first washer should fit in to?

Regards,

Andrew.

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G.day Huppers. Andrew the boss on the crankcase that the first Pbi disc runs against needs to be flat and the face be at rt angle to the axis of the crankshaft. It is common for this boss to be worn away . In your second picture it looks to me that this boss needs facing off. As mentioned earlier I set our crankcases up in the lathe and faced them off. then to prevent the bronze plate running against this boss I secured it to the crankcase with 3 of 3/16 th countersunk head screws . I secured the other bronze plate to the clutch so that the piece in the middle, I think I used stainless steel, has no alternative but do the work it was intended to do. Max Burke Nulkaba 2325 Australia

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Hello Andrew,

I have taken a couple of photos for you which may help. Or they may raise more questions.

One show the radius or fillet on one of the bronzes.This one would fit towards the clutch drum.

Another shows the shoulder on the other bronze thrust washer.

I'm not sure the shoulder fits into a recess at the back of the engine. That seems logical enough, but looking at some old stock I don't see the evidence. Everything I have looked at appears flush.You will see in another photo the fibre washer fits to the shoulder.Hmmm?

I can't say I agree with attaching the bronzes to either the block or the clutch drum ( with all due respect to Max). The factory didn't do it ,and it seems like that would make the fibre washer do all the work there.

I would agree with Max regarding the end play or float. I will admit to not being an expert,and not getting mine right the first time,or even if it's quite right yet.

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  • 2 weeks later...

Hello Ken,

Thank you for the 2nd set photos, they certainly clarify the radius and the shoulder. I appreciate it. I must say I am undecided about the issue of fixing the washers to the block or clutch drum as I value both opinions I have been given here. However, whatever way I go, I guess it is not too huge an issue to try something else if it doesn't work as I was surprised how easy (relatively) it was to pull motor and gearbox out. I also have a 1912 Minerva which has a thumping great 4.4 litre sleeve valve engine and I dread the thought of ever having to pull it out!

Regards to all,

Andrew.

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