[Greybeard]

Thanks, Peter. I do intend to keep the bike ready for use over the winter, weather permitting. It's the only one I haven't spent a lot of time restoring the cosmetics of so far 
I did replace the mainbearing early in this saga as the original's bearing tracks were starting to break up, probably as a result of trying to restrain the dancing gearwheels over the years of neglect. I decided not to fit an oil seal for the time being as the original seal seems to do a reasonable job of keeping the grease in. I do add some 140 gear oil to the semifluid grease and I'll see how it goes. As there are points lower in the box that have no effective seals, running it in nothing but oil would do little for the workshop floor 

Steve

[peter wright]

Well, I'm pleased you have got that sorted out. I actually think they are a very good and robust gearbox so should give you years of service now.

Did you replace the main bearing and fit a seal arrangement to it? I'm still struggling to locate a bearing for my CP. I will drop the out the one that is in it and put in under the magnifying glass and maybe reuse it. It certainly feels fine and on a 250 will never be subject to the loads of a bigger bike, although it could be spinning faster due to the gearing.

I hope you get some use out of it over the Xmas break.

Cheers,
Peter

[Greybeard]

I finally got the parts I needed - after a further exchange. Did you know that Burman sneakily changed the bore of the 2nd and 3rd gear layshaft cogs from 1 inch to 1.0645 during production? Neither did the chap who supplied the first pair. Anyway, the correct new cogs and the other replacements I found were fitted and I'm pleased to report that serenity has been restored in the transmission department. Hopefully I'll never have to see the inside of that gearbox again 
The only parts of the original box that have gone back into it were the mainshaft, the layshaft and the layshaft sliding gear. Not a cheap exercise but one that needed doing. The top row in the picture are the discarded bits

Steve

[Greybeard]

I was hoping to have some good news by now, but thanks to the Vincent Owners Club shop it is not to be. I have found that the £300 worth of parts I ordered two weeks ago had been sent to a different postcode (that, incidentally, is no longer in use) somewhere in Surrey - apparently due a typing error. The new delivery was initially promised for Thursday after the parcel was eventually traced, then a further promise for today - and still nothing. I have contacted Yodel myself who now tell me that it could be anytime in the next 72 hours 
To say that I am not a satisfied customer is to put it mildly. In the meantime the Sunbeam stands disembowelled and idle.

Steve (wot foolishly expected better)

[iansoady]

I do wonder how much it would cost to get gears made on a CNC machine. Bob Rodgerson (Humbernut on the IKBA forum) is a very experienced machinist and has just purchased such a device - to keep his mind in gear after retirement. He is making some complex articles and I would have thought a gear wheel - provided there was something reasonable to get dimensions from - wouldn't pose too much of a problem. It may well be worth asking him whether he would be interested as once the program is set up it would be easy to replicate them.

Just a thought.

[Greybeard]

Hello, Peter.
I've just logged on to send John (singleminded) a PM as it happens. I've tracked down a pair of virtually unused 3rd gear cogs from Les Dawson at PD Engineering in Pontefract and went over to collect them this afternoon. He also had a near new driving gear and a mainshaft sliding gear, both pristine. The cost of new ones is over £800 just for those four so getting these for a quarter of that price was a real bonus 
That left me with a decision to make. For only 140 extra I could replace both 2nd gear cogs and the driveside layshaft one. In effect a practically new gearbox. Needless to say, getting the bike back together and properly sorted is the priority so the order has been placed. Perhaps by this time next week I'll be able to report that serenity has returned to Lion's transmission. This time it'll have it's semi-fluid grease supplemented with an eggcup full or two of SAE140 Golden Film just to make sure it gets everywhere it should.
One thing I have been surprised at though is the variety of BAP gearboxes. I knew that the casing of the ones fitted to SQ4s differed to accommodate the chainline, but Les D showed me, today, a casing that was stamped BAP but was in effect completely inverted compared to mine. My box pivots from the top mount with the adjusted beneath, this one had the adjuster on top.
I's a minefield out there. You'd certainly need to see a gearbox before buying on the basis of its model number 

Steve

[peter wright]

I would have thought that usable 2nd hand gears wouldn't be that hard to find, as so many bikes used the BA, and typically the internal ratios were similar for most.

Have you tried the Club Spares (Les Hobbs) or Draganfly, maybe Russell Motors also?

Peter

[Greybeard]

I had a look at the VOC shop this afternoon - mainshaft 3rd gear is out of stock anyway and I'm awaiting a response regarding when they are likely to reappear 
With luck, John will come to the rescue, if not I'm stuck with an expensive ornament in the workshop 

Steve

[iansoady]

Looks nasty.

I always find that photos do exaggerate what look like small imperfections to the naked eye (especially on my machining!) but the layshaft gear in particular does look in a state.

[Greybeard]

More on this long-running saga  and some horror pictures. Not for the mechanically squeamish.
So far it has been a process of elimination. The mainshaft is nowhere near as bad as I had first thought and my thanks go to John for sending me the bronze sleeves that made checking the shaft on a surface plate possible. Run-out is no more than around 4 thou, which shouldn't be a worry.
I then removed the endfloat on the mainshaft to a barely perceptible amount by making up a shouldered washer for the end of the shaft at the kickstart end. By the way, you can remove and replace the mainshaft quite easily with the box still in the bike without difficulty. I supported the gears with a suitable bar until I replaced it. Anyhow, it brought no improvement.
Next step was to try replacing the layshaft bushes, which I did, courtesy of new ones from the VOC. These were reamed to size, 21/32nd inch, after fitting as they nipped up just a tad too much after fitting. Still no improvement. Turning the box by hand revealed grumbling gears in 2nd and mainly in 3rd. 1st and 4th were silent.
This suggested to me that there was some problem present between a pair or pairs of gears meshing. I then began some juggling, removing some gears whilst still being able to rotate the box. Removal of the 30T third gear removed the rumbling.
Closer examination of the teeth under a lens appears to confirm what I'd previously read. Wear on the third gear teeth can cause such a racket. I suspect it has probably been caused by the box being used over an extended period with worn bearings/layshaft bushes that has led to the teeth being misaligned.
I've done a couple of pics using a Nikon SLR with a Micro lens. The results look even worse than in real life 

30T mainshaft gear -


24T layshaft gear, which took a considerable amount of force to pull off. I hope I can get another one back on 


I told you they were nasty, didn't I?
John has offered to delve into his box of parts for me to see if better replacements can be found. If not then I fear that I'm about to become a member of the VOC and go shopping for new cogs  At least I'll know what I'm getting for Xmas 

Steve

[peter wright]

Pleased to have helped. Sometimes its easier to meet up and point at things, or draw a sketch at the pub over a beer, than diagnosing problems from 12000 miles away. Being bit of a bodger myself I would try a suitable washer or shim under the nut rather than a longer sleeve. Another consideration, although probably more academic than real, is that a longer sleeve will take a bit of pressure off the k/s ratchet spring.

So no need to abandon the Sunbeam just yet and getting an Ariel or BSA. I consider Val Page one of the finest engineers and I have a bunch of pre-war Ariels awaiting attention to prove the point. That might be sacrilege on this forum but it can't be denied that some aspects of the later bikes, nice as they are, left a bit to be desired. Just thought of a funny in how they brought a new meaning to brake (break) shoes. Well I laughed anyway, but that's another story.

I've an idea I've seen pictures of your bike somewhere but can't find them now. I should be able to confirm whether your gearbox is indeed Sunbeam and therefore likely to be the original.

Peter

[Greybeard]

The mainshaft is completely free at the drive end and can move any amount (until it causes the clutch to contact the chaincase). The float is controlled by the freedom at the kickstart gear sleeve

Flash of 'understanding' whilst waiting for the kettle to boil this morning You're absolutely right, Peter. For some inexplicable reason  I had it in mind that the mainshaft was limited in its movement to the right by the outboard end of the driveside of the shaft. Of course it isn't.  A new kickstart sleeve is required, methinks. I shall make a replacement after I've had a go at straightening the blighter. Thanks for the 'prod of comprehension', Peter.

Steve

[Greybeard]

I must admit, there are times when I wish I'd bought an Ariel  or another BSA
First task I think is to try and straighten the mainshaft and sort out the endfloat (whether by gaskets or kickstart gear sleeve) and see what effect that has. I'm getting quite adept at dismantling the Lion now.
22 different mainshafts for the same box? No wonder we lost the plot  I'll measure up the shaft tomorrow, Peter. Of course, there's nothing to confirm that this gearbox is actually the one that the bike started its life with, if it comes to that. I understand that the the Ariel SQ4 version of the BAP had a different casing to take account of the offset of the primary drive so I can be reasonably sure it's not one of those variants.

Steve

[peter wright]

Have you got the 1937 Burman parts book? I have just looked and see it lists a washer for the k/s side bearing (37/1BA "mainshaft bearing washer"). Not sure which side of the bearing it is supposed to go but if under the bearing it will have a small influence on the endfloat. Guess the question is whether the circlip is tight to the bearing or a gap might suggest this washer is missing?

One way to cure at least some of your woes is a new shaft but the parts book lists 22 versions. Not all 1937 but covering all years up to then. Sadly there is no reference to which one is Sunbeam because it would have been useful to know which other makes used the same shaft. HRD is lumped with Ariel for pre-'36 but this doesn't get you far. More research is needed to discover whether the VOC ones would suit the Sunbeam.

Afraid I can't agree with your comment about the gasket. The gasket thickness will certainly affect the float of the layshaft as it runs between the flanges of the bushes in the cases. In fact increased float here from a thick gasket might be a negative as it could reduce the indexing of 1st and 2nd.

The mainshaft is completely free at the drive end and can move any amount (until it causes the clutch to contact the chaincase). The float is controlled by the freedom at the kickstart gear sleeve. I would hazard a guess that all BA 'boxes have the same length of shaft between the sliding gear spline and the end (at least up to the oil 'box change in '48). If you measure this I could try and find a shaft to compare. Certainly this dimension is what controls the float (in conjunction with k/s gear sleeve and thickness or 3rd gear). Unless it is quite different to the CP arrangement I am familiar with.....

Hope this helps, and saves some of those precious hours in bed.

Want to get back to my CP this w/e but doubt that will add any insights.

Peter

[Greybeard]

Its certainly a conundrum, Peter. Im still minded that moving the inner case out from the main casing by adding a gasket will tend to decrease the endfloat though. In effect it makes the space between the bearings slighly wider so to give the same endfloat the shaft would have to be the thickness of the gasket longer  As the mainshaft is not held at either end when assembled it is free to move side to side within the bearings. Thats my reasoning anyway. Ive spent many happy hour lying in bed thinking about this. Of course I may have got it all wrong 
Like you I think that a combination of a bent shaft and the endfloat may be enough to vary the mesh between the gears sufficiently to creat the noise. I cant find any witness marks on any of the components that might confirm this though. Perhaps the 'bow' in the shaft is enough to cause the 2nd and 3rd gear pinions to oscillate side to side. I really dont know, but one way or another Im determined to get to the bottom of it.

Steve

[peter wright]

I was mulling this over some more and realised that adding a gasket will have no affect on the endfloat. The float is controlled by the bearing in the inner cover and the kickstart spacer and cannot be influenced by the position of the cover itself. A gasket will merely adjust the cover sideways, and with it the bearing and shaft.

It would be my feeling that the cyclic noise is due to the bent mainshaft and it will be interesting to hear (so to speak) whether straightening the shaft improves or cures it.

I was also wondering whether the scraping component of the noise could actually relate to the endfloat issue. If the shaft can move, then presumably so can 3rd gear and I wonder whether this might allow it to contact or brush against the dogs of the sliding gear? Just a thought, and I would have to play with a set of gears to see if it was even possible.

Peter

[Greybeard]

Hello, Peter.
thankfully the endfloat is well short of an 1/8th, without checking again, I'd estimate it as about 1.5 to 2mm so I'm pretty confident that it is the right length of shaft and much of that would be taken up by a 1mm gasket. The book of words does make mention of fitting a longer sleeve for the kickstart pinion to run on or machining a shoulder on the nut so it pases over the end of the mainshaft to reduce the clearance. Of the two, the first would work and I may have to machine one up when I reassemble the box. The second method would require a larger diameter nut as the flats are very close to the diameter of the mainshaft itself, so it would not have sufficient meat left on it to last very long.
The noise is difficult to describe, but is an oscillating whining/scraping noise as if something is running out of true. It is noisier on the overrun. The actual source of it has eluded me so far, but it does marr the pleasure of riding what otherwise is a very pleasant machine. As Ive said, first and top gear are completely silent.
It might well be a process of elimination at this rate, which could prove expensive if I select the wrong order in which to try the remedies. The potential of obtaining another gearbox hasn't materialised so far.

Steve

[peter wright]

I've scanned down this thread again and can't see where you might have told us what the excessive mainshaft endfloat is?

You've astutely noted that adding a gasket to the inner cover will reduce the endfloat. This is sort of the opposite to what one might normally expect to happen and tells me you see the mainshaft floating at the kickstart side bearing. If this is the case a longer kickstart pinion sleeve might help, but if the float is about 1/8" you might have a shaft from an oil 'box as I mentioned below somewhere. Or the mainshaft free gear (3rd?) is too thin for some reason......

Before considering a VOC mainshaft I'm sure you will check the length or compare original Burman parts numbers. A while ago I discovered that the CP mainshaft and sleeve gear for my 250 were different to the AJS/Matchless version so couldn't use some n.o.s. bits I have.

This may not have helped at all, of course.

Peter

[Greybeard]

I pulled out the gearbox mainshaft tonight (it comes out easily and can be replaced by a suitable bar following it through from the kickstart end of the box, to aid replacement) and got it mounted between centres on the lathe and also in the chuck to check the run-out. It does look like it's bent to some degree but identifying where the actual bend is may be more tricky. It looks like it's off anywhere between 40 and 95 thou!  I feel sure that that could be affecting the meshing of the gears and causing the whine and also messing up the primary chain tension.
Another thing I've noted is that an inner case gasket should perhaps be fitted to this box. That could be contributing to any excessive endfloat of the mainshaft I suppose as the cases will be closer together without one.
I wonder if it is possible to straighten the shaft as John (singleminded) has done previously. Otherwise it's going to be a visit to the Vincent Owners Club and a £238 bill.

John, did you come across those sleeves you made by any chance?

Steve

[peter wright]

For what its worth I can advise that it is possible to extract the mainshaft with the gearbox in position and then reinsert without all the gears falling into the bottom. I did this as an experiment with the CP 'box in my '37 250 and would think the BAP would be similar.

Of course the kickstarter cover has to come off to remove the nut then a dowel or rod can be fed through as the shaft is withdrawn. I think I engaged top gear first so the sliding gear was held in the sleeve gear by the selector and this helped with jiggling the shaft back in.

Another thing to be careful with is mixing parts with the post-47 oil filled Burmans. There were some subtle changes along with the introduction of bronze bushes for some of the gears. With the wrong combinations of parts there is the potential to lock it solid or create monstrous endfloat on the mainshaft when the nut is done up. For instance an "oil" mainshaft sliding gear will fit a "grease" 'box but not the other way round. I very much doubt this has anything to do with your mainshaft issue or grating noises but worth bearing in mind if you believe the 'box has been messed with in the past.

Peter

[Greybeard]

Having got the bike back together over the last few days I had chance to ride it over 25 miles yesterday and am pleased to report that it's much improved. There is still a quieter background whine from 3rd gear, less so in 2nd and both fade as the revs increase. Something still occasionally sounds like it's catching/rubbing somewhere on the over-run but it has eluded me so far. I painted the inside of the chaincase black which revealed a couple of contact points - perhaps I've missed one  Apart from that serenity is restored - in top gear anyway 
Thanks for the help/suggestions so far. Once winter arrives with a vengeance I'll strip out the mainshaft and check it's alignment and reduce the endfloat further to the minimum recommended.
In the meantime I'm being diverted by a Matchless tank that I'm partway through treating with rustkiller/sealant, and also a tiny 1927 Francis Barnett Super-Sport  172cc 2-stroke. I may yet decide to use it as a keyring if I find that it's too small for me 

Steve

[Greybeard]

That sounds like a sensible and safe way to do the job, John. Thanks for the tip.

Steve

[singleminded]

When i did my Mainshaft I made 3 bronze sleeves all the sam OD,but made to fit the mainshaft near the clutch end the middle and the kickstart ratchet end.
I use a set of V blocks and a dial gauge on a stand and checked the run out..By then positioning the shaft under the press on the V blocks with the bend upwards I slowly removed the 50 thou run out to about 3-5 thou..Its been in my comet for years now..
I was suprised at how much pressure you could put on the shaft..Someone told me that the shafts can bend after years of sidecar use..John

[Greybeard]

Straightening the shaft sounds like a risky business to me, but what is there to lose if it's bent anyway  A mate of mine has a press which I could use. I'd just be wary of overcooking the pot and ending up with an S-shaped shaft 
I had an email earlier about another potential gearbox being found, so all might not be lost just yet. I have checked the mainshaft by rotating it with the clutch plates removed and it certainly alters the chain tension a little so it's obviously not running perfectly true. On the plus side, running the engine without the chaincases has got rid of some of the noise though there is still that whine in 2nd and 3rd - more than I would expect of any straight cut gearing. I'm not sure that I want to punt 240 quid on a new shaft by way of an experiment just yet 

Steve

[singleminded]

I've pulled the mainshaft out of a complete box when it's been on its end in a vice..You may find the gears will drop out of place in the bike,,But what have you got to lose??.
I managed to straighten my mainshaft with the use of a 50 ton flypress in my local bike repair shop.I was allowed full use of this press as it was my own risk.Good old fashioned place where the owner is a proper engineer.John

[Greybeard]

Good point, John. I've had problems getting anywhere near an even primary chain tension (it's a new chain so I know it shouldn't be unevenly worn). There's a slight run out on the clutch chainwheel but a bent mainshaft may well account for some of it. If it is bent, I wonder if it's possible to change the mainshaft without stripping the entire box - it'd be tempting to try it. It should pull out from the drive side.
I've found a couple of spots where the outer edge of the clutch basket looks like it has been catching the outer chaincase at the top, and also possibly on the oil retaining flange on the inner case by the rubber shock absorber covering washers.
I've been able to ease the thickness of the flange enough to give a good clearance, and I think that by gently levering the inner case upwards before tightening it onto the frame/crankcase bolts I've gained about 3-4mm which should help with the gap inside the 'dome'. Hopefully this should keep the things clear of one another. It could be improved further by fitting a gasket between the out and inner covers, but I'd have to search for a large enough piece of gasket paper to make one first.
The way this is going I should be quite the little expert on primary drives and Burman boxes once it's sorted 

Steve

[singleminded]

While you have the cover off check that the clutch actually runs true..I had a BAP mainshaft on a Comet box that was bent by 50 thou. I had problems with the gears and clutch alignment..John

[Greybeard]

Yes, I had that in mind for tonight. Ive just taken the outer case off and there is what looks like aluminium dust in the fresh oil. Ive just got to find where the beggar is catching now. There is a mark on the inside of the top of the 'clutch dome' if you understand what I mean. Ive got the straight edge and calipers out to see if thats where it could be touching. Marstons obviously kept clearances to a minimum to save an ounce of aluminium 

[iansoady]

Is it worth removing the primary chaincase complete and trying it like that to eliminate it?

[Greybeard]

Well, it's all back together ---- and there's no improvement  It's as if something's scraping in 2nd and 3rd. I'm going to have to check on the clearances for the clutch within the chaincase, though I did make up spacers that I thought would give it some additional clearance and align the clutch sprocket with the engine sprocket. It's not as if there are any fresh tell-tale marks to be seen to give me a clue.
All I have noticed is that the noise seems to be worse at lower revs. and it still does it with the engine running when on the stand. I know the endfloat on the mainshaft is at the upper limit of tolerances given in the Ariel book for the same box, though the method of countersinking the end nut to reduce it wouldn't work because of the size of the nut. I'll have to fabricate another way of resolving that issue.
Never had this problem with a BSA or a Matchless 

Steve

[Greybeard]

Hello, Peter.
I believe the type of kit I was looking for, and is shown on the Vincent spares site, is pretty much as you've described making - a thin top hat arrangement that is held in by the circlip with a flange to take the rubber seal. I have emailed the Vincent folk to confirm whether theirs will fit the BAP box, but have as yet had no response. Perhaps I should resend it and hopefully it will get picked up. Until then mine has gone back together with the original sealing washers - and semi-fluid grease. Should a response be forthcoming, I'll let you know.

Steve

[peter wright]

There are lot of words in this thread below and I haven't read them all so could be going off at a tangent here, apologies if so.

I'm interested in the gearbox sealing issue as I would like to do similar for my 1937 250 if parts are available. I believe the CP for the 250 will be similar in principle to the BAP in this regard so the following might be relevant.

There was a fundamental change to the sealing arrangement for 1938 when the previous close-running, and overlapping, plates were replaced by a felt seal. This is in line with the mention below of the earlier housing being too shallow. Basically there is not enough depth behind the circlip to fit anything thicker than the steel plate.

The 1938 change allowed a ring holding the felt seal plus a pair of support plates to fit under the circlip. All this was about 3/16" or 1/4" thick. When they changed from grease to oil for 1948 the felt was replaced by a rubber seal. I'm not sure what the kits referred to include but I think the rubber seals are available and can simply replace the earlier felts.

Last time I looked at the Draganfly site I don't think there was a photo of what they offer so I can't confirm which type it is intended to replace. On another forum someone advised they got a kit from Russell Motors for a 1937 CP but when I pressed him for details I got no response. I also can't find it on Russell's site and unfortunately they don't do email.

If I am talking through a hole in my hat and something is available for the early type 'box I would like to know about it. Beyond that I can only suggest you carefully check what is being offered and that it will fit under the circlip.

Having said that, it is not impossible to solve. I made a tophat seal holder with a thin brim to go under the circlip for an even earlier Burman and it worked a treat. I was, however, fearful the "brim" may not have offered enough resistance to stop the whole plot turning so I added a form of torque arm to hold it.

I have had a similar discussion on the Ariel group and the general opinion is that the early plate "seals" aren't too bad; the grease simply leaks out until it stabilises at the correct level. Messy and a bit disconcerting! Obviously it would be wise to check the level from time to time.

Hope this helps.

Regards,
Peter

[singleminded]

Yes,That's the type of paint I used..Found a self glossing 2 pack from Nu-agane paints..Really deep black and no lacquer needed..John

[Greybeard]

I've just emailed them, thanks, John. It's shown as out of stock at present. Hopefully they'll be able to tell me when it'll become available. if it's a while then it isn't a big job to fit it later with the 'box still in the frame.
I see they do the cast selector forks at a reasonable £60 or so.
Still patiently awaiting the roller bearings from Draganfly 

As an aside, I finished respraying the chaincases with 2-pack yesterday. Probably the best finish I've had  - more like black chrome than mere paintwork  It means I'm going to have to tackle the rest of the paintwork sooner rather than later now 

Steve

[singleminded]

Try the Vincent owners spares Co..
01536 312220..
Part no  PR50-112BA/seal kit  Not cheap but!!!l..Fits the BAP box for a Comet..That must be where I got mine.this should fit as the series A used a BAP box as well..
This comprises of a housing and seal to fit the gearbox..The housing goes in the recess and the seal fits in the housing.
Also ask about the other bits you need. The layshaft bush appears to be in stock at about £14..John

[Greybeard]

I've just had a reply from Draganfly about the seal and carrier They tell me it'll not fit the BA box due to lack of depth in the housing. Back to plan A 

Steve

[Greybeard]

No problem, John. The mainshaft one has 42 BA and the layshaft one has 43 BA. Both also have VAF cast onto them. My mainshaft fork has some wear but as it was working OK it can go back in for the time being.
I've emailed Draganfly in the hope they'll add the seal and housing onto my order.

Steve

[singleminded]

If you still have your box in bits can you look at the selectors to see what the CAST in numbers are please..Hopefully something like B42 and B41..John

[singleminded]

I fitted one to my Vincent Comet and it has been ok for years..John

[Greybeard]

Ive been considering fitting the modern oilseal and housing kit/carrier as supplied by Draganfly. Hopefully that would help in keeping 'runnier' grease inside the box and dust outside, perhaps more efficiently than the existing simple shield arrangements. Has anyone else tried this alteration on the later 'beams?
Having said that, the bearings were ordered over a week ago and according to an email last night theyre still waiting to be packed 
Steve

[phutton]

But don't use an EP oil, as when it leaks onto the clutch plates, they will never grip again!

[Greybeard]

Oh, yes. Penrite semi fluid grease for burman boxes and I'll probably mix a bit of SAE 140 Golden film in with it just to make sure it gets everywhere - preferably inside the box 

Steve

[iansoady]

You also have to be careful if using gear oil as certain grades (GL5 springs to mind) attack yellow metals such as bronze and brass.

[phutton]

Have you tried the Vincent Owners' spares shop for the bushes?

[Greybeard]

Thanks, John. Youve confirmed what I  understood in that there was some danger in using the wrong grade if the box isnt oil fed. I had thought sintered bronze would be ok, but apparently its as likely to seize as phosphor bronze. A real minefield, eh? I was going to try ringing one of the oilite bearing manufacturers to see what they had, though it may be as well to sit tight until Draganfly get some stock. At only 11 quid apiece it barely seems worth the effort of tracking down the material and making them 
Im hoping that new roller bearings will suffice. If they dont cure the noise its not a long job to strip it and try again.
If i do have to fit new bushes I think Ill play it a bit safe anyway and mix some extra SAE140 oil in with the semi fluid grease.

Steve

[singleminded]

Be careful if you use bronze for the bushes..I saw a box from a Vincent Comet(later BAP) that had bronze bushes made for the layshaft..It was used with grease which did not lubricate the bushes correctly and siezed..this caused the drive end bush for the layshaft to turn in the casing..difficult repair!
If you use bronze then you may have to use oil in the box.I do.John

[Greybeard]

Hi, folks.
As I described in my introductory post, I was experiencing a lot of transmission whine/noise in 2nd and 3rd of my 1937 Lion. I had originally thought that this was typical of worn layshaft bushes. I've stripped the gearbox now and finally cleaned up the semi-fluid grease it was filled with. The bushes for the layshaft don't seem too bad at all. I've certainly come across far worse on gearboxes that were totally silent. Similarly there are no apparently worn teeth or sliding gears.
What I did notice when I was stripping it was some foil like slivers of metal around the output gear dust shield, like slivers of tin foil, but in steel. The biggest was almost 1/4 inch across. Cleaning the output roller bearing and looking at the tracks under a magnifier, it does look like some of the surface hardening has lifted. Whilst the bearing itself doesn't have a lot of play there are certain times when it is spun that it sounds like a train is coming! the kickstart end roller bearing does have some wear but nothing drastic. There are quite a few metal flakes in the old grease too.
I'm hoping that a new pair of rollers will cure it (the layshaft bushes from Draganfly won't be available until the end of September at the earliest so unless I can find some suitable bronze to make some I'm stuck with what I've got for the time being).
Does anyone know what the permitted endfloat of the layshaft should be on a BAP box, or is it not so critical? I've found the recommended amount for the mainshaft only so far (courtesy of Mr. Waller's book of the Ariel).
Any other suggestions as to what may be a source of the whine will be gratefully received of course.
I'll pay the local bearing stockist a visit on Monday to see what he has - at trade price, naturally and with luck I may have the old girl back on the road soon.

Steve