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Author Topic: BAP gearbox noise in 2nd and 3rd  (Read 8913 times)

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Greybeard

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Re: BAP gearbox noise in 2nd and 3rd
« Reply #47 on: December 21, 2015, 09:26:50 AM »
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
1927 Francis Barnett model 9 Super-Sport 172cc
1937 Sunbeam Lion 500cc
1952 BSA A10 Golden Flash
1953 Matchless G9 500cc
1953 BSA B31 350cc
1958 Ariel NH350 Red Hunter
1961 Matchless G80 500cc
1961 AJS M31 De Luxe 650cc
2007 Triumph T100 Bonneville
1960 Rover P4
1979 Triumph Spitfire

peter wright

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Re: BAP gearbox noise in 2nd and 3rd
« Reply #46 on: December 20, 2015, 09:08:04 PM »
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

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Re: BAP gearbox noise in 2nd and 3rd
« Reply #45 on: December 20, 2015, 11:59:01 AM »
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  ;D
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
1927 Francis Barnett model 9 Super-Sport 172cc
1937 Sunbeam Lion 500cc
1952 BSA A10 Golden Flash
1953 Matchless G9 500cc
1953 BSA B31 350cc
1958 Ariel NH350 Red Hunter
1961 Matchless G80 500cc
1961 AJS M31 De Luxe 650cc
2007 Triumph T100 Bonneville
1960 Rover P4
1979 Triumph Spitfire

Greybeard

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Re: BAP gearbox noise in 2nd and 3rd
« Reply #44 on: December 11, 2015, 03:36:48 PM »
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)
1927 Francis Barnett model 9 Super-Sport 172cc
1937 Sunbeam Lion 500cc
1952 BSA A10 Golden Flash
1953 Matchless G9 500cc
1953 BSA B31 350cc
1958 Ariel NH350 Red Hunter
1961 Matchless G80 500cc
1961 AJS M31 De Luxe 650cc
2007 Triumph T100 Bonneville
1960 Rover P4
1979 Triumph Spitfire

iansoady

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Re: BAP gearbox noise in 2nd and 3rd
« Reply #43 on: December 02, 2015, 11:00:05 AM »
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.
Ian
1931 Model 10
1993 Honda CB400 Super Four

Greybeard

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Re: BAP gearbox noise in 2nd and 3rd
« Reply #42 on: December 01, 2015, 09:00:47 PM »
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
1927 Francis Barnett model 9 Super-Sport 172cc
1937 Sunbeam Lion 500cc
1952 BSA A10 Golden Flash
1953 Matchless G9 500cc
1953 BSA B31 350cc
1958 Ariel NH350 Red Hunter
1961 Matchless G80 500cc
1961 AJS M31 De Luxe 650cc
2007 Triumph T100 Bonneville
1960 Rover P4
1979 Triumph Spitfire

peter wright

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Re: BAP gearbox noise in 2nd and 3rd
« Reply #41 on: December 01, 2015, 08:43:21 PM »
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

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Re: BAP gearbox noise in 2nd and 3rd
« Reply #40 on: November 26, 2015, 04:54:33 PM »
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
1927 Francis Barnett model 9 Super-Sport 172cc
1937 Sunbeam Lion 500cc
1952 BSA A10 Golden Flash
1953 Matchless G9 500cc
1953 BSA B31 350cc
1958 Ariel NH350 Red Hunter
1961 Matchless G80 500cc
1961 AJS M31 De Luxe 650cc
2007 Triumph T100 Bonneville
1960 Rover P4
1979 Triumph Spitfire

iansoady

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Re: BAP gearbox noise in 2nd and 3rd
« Reply #39 on: November 22, 2015, 03:18:46 PM »
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.
Ian
1931 Model 10
1993 Honda CB400 Super Four

Greybeard

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Re: BAP gearbox noise in 2nd and 3rd
« Reply #38 on: November 22, 2015, 02:01:26 PM »
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  :o

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
1927 Francis Barnett model 9 Super-Sport 172cc
1937 Sunbeam Lion 500cc
1952 BSA A10 Golden Flash
1953 Matchless G9 500cc
1953 BSA B31 350cc
1958 Ariel NH350 Red Hunter
1961 Matchless G80 500cc
1961 AJS M31 De Luxe 650cc
2007 Triumph T100 Bonneville
1960 Rover P4
1979 Triumph Spitfire

peter wright

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Re: BAP gearbox noise in 2nd and 3rd
« Reply #37 on: November 14, 2015, 12:01:01 PM »
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

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Re: BAP gearbox noise in 2nd and 3rd
« Reply #36 on: November 14, 2015, 09:12:20 AM »

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
1927 Francis Barnett model 9 Super-Sport 172cc
1937 Sunbeam Lion 500cc
1952 BSA A10 Golden Flash
1953 Matchless G9 500cc
1953 BSA B31 350cc
1958 Ariel NH350 Red Hunter
1961 Matchless G80 500cc
1961 AJS M31 De Luxe 650cc
2007 Triumph T100 Bonneville
1960 Rover P4
1979 Triumph Spitfire

Greybeard

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Re: BAP gearbox noise in 2nd and 3rd
« Reply #35 on: November 12, 2015, 10:29:53 PM »
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
« Last Edit: November 12, 2015, 10:44:28 PM by Greybeard »
1927 Francis Barnett model 9 Super-Sport 172cc
1937 Sunbeam Lion 500cc
1952 BSA A10 Golden Flash
1953 Matchless G9 500cc
1953 BSA B31 350cc
1958 Ariel NH350 Red Hunter
1961 Matchless G80 500cc
1961 AJS M31 De Luxe 650cc
2007 Triumph T100 Bonneville
1960 Rover P4
1979 Triumph Spitfire

peter wright

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Re: BAP gearbox noise in 2nd and 3rd
« Reply #34 on: November 12, 2015, 10:10:07 PM »
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

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Re: BAP gearbox noise in 2nd and 3rd
« Reply #33 on: November 12, 2015, 12:46:18 PM »
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
1927 Francis Barnett model 9 Super-Sport 172cc
1937 Sunbeam Lion 500cc
1952 BSA A10 Golden Flash
1953 Matchless G9 500cc
1953 BSA B31 350cc
1958 Ariel NH350 Red Hunter
1961 Matchless G80 500cc
1961 AJS M31 De Luxe 650cc
2007 Triumph T100 Bonneville
1960 Rover P4
1979 Triumph Spitfire