3rd gear noisy

[Pete Gray]

I've just read an Ebay description on an A10 for sale which refers to the notorious 3rd gear noise.

Mine is, and always has been, noisy from the transmission in 3rd. Is this "notorious" and therefore expected?
I replaced the gearbox final drive bearing some time ago.
I don't think it's got any worse over time but is sometimes very noticeable on a steep pull uphill.

[bsa-bill]

Don't think they all do it Pete, but a lot do, mine and a mates both whine in third

[Goldseeker]

Mine is also quite noisy and was worried about it until I read the posts on this site.

Is there a known issue/cause that I can investigate in the winter or is it a 'characteristic' that you just have to live with?

[BSA_54A10]

You can get rid of the 3rd gear whine but it usually requires a complete rebuild of the gearbox and some new cogs.
The whine is due to improper meshing of 3rd and if it has been doing it for a while then you will need a new pair of 3rd gears and new bushes and new shafts and some work on the selector and the forks and about 100 spare hours.

[Pete Gray]

So it's probably best left alone then - put up and shut up !

[Goldseeker]

So it's probably best left alone then - put up and shut up !

Looks like it. 

[bsa-bill]

Take a positive view, when it whines you know what gear your in, lesser makes have gear indicators, with these you have to look down to know

[a10 gf]

Adding my membership to the '3rd gear whine club', but reading

requires a complete rebuild of the gearbox

looks like it won't (and doesn't need to) be fixed before something else goes wrong in the box.

[A10Boy]

A mate of mine is an expert BSA gearbox repairer. Its all he does now his knees are dodgy. He rebuilt mine with all new bearings bushes gears, springs, selectors etc. He did it in 3 days as he has loads of spares in his workshop - and it was cheap. [A well known gearbox / restoration company in the UK told me they take four weeks minimum].

If anyone in the UK needs gearbox work, contact me and I can arrange it.

[Butch (cb)]

Mine was rebuilt with the best bits from a couple of boxes, and whines in third. So interesting to hear it's all pretty normal. Mind you the bike has seized, and I think it's the transmission. I'll post on that shortly.

[chaterlea25]

Hi All,
I recently rebuilt a STD box machining the worn layshaft and fitting new u/s bushes to suit amongst all the other repairs
I replaced 1st gear pair and the layshaft driving and mainshaft sleevegear with some gears from my spare gearbox
2nd and 3rd looked OK
When riding the bike 2nd could be heard and 3rd screamed like a bas*a*d!!! when under load (no noise on the overrun)
I stripped it again and replaced 2nd and 3rd gear pairs from the spare box
Still the same  ???? ???? ???? ???? ????
I changed the oil to 85/140 to see if that helped, NO
The gearbox is free turning in all the gears and there are no metalic bits in the oil after a 1000 miles or so
gear change is sweet

On my own SR when I rebuilt the gearbox with nearly all new parts I could still hear 3rd gear growling on acceleration
after hearing the other box it now seems very quiet (maybe I'm gone deaf??) after 10k miles or so

Question is will "new" gears sort out the screamer  ???? ???? ???? ????

Regards
John O R

[wilko]

That's why i wear a balaclava under my helmet for sound proofing, i'm oblivious to my third gear!

[groily]

Having read all this I'm leaving mine alone for a while! 3rd gear is noisy under light load, and 2nd audible. Was going to 'do' the layshaft and bushes, but looks as if it might take a lot more than that, and then there'd be no guarantee of an improvement without the '100 spare hours' and a load of cost per BSA54A10's very pertinent comment. I also tried heavier oil, no different. The box in my B, by contrast, is silent, although there is some slight wear evident on the layshaft bushes. I think while it ain't broke, I'll just carry on for now with the A using the tight-fitting hat 'cure' like wilko.

[Slymo]

I have a noisy third gear but have decided that its the final drive layshaft pinion that makes the racket. I have replaced all the other cogs and the noise remains exactly the same. The gears other than top all run through the constant mesh 17 tooth layshaft gear and the 26 tooth sleeve gear pinion. This is the pair that make the noise and I'm guessing mostly from the layshaft side and mostly in third gear because of the load. I've recently been told that honing the tooth faces with a slip stone to smooth the faces and to round off the sharp edges with considerably quieten them. Anyone heard of this or given it a go?

[Slymo]

Obviously not a hot topic this one. Still I have polished the pinion teeth on my constant mesh gears with a fine stone and will let you all know the outcome in due course.