Another question if I may please
I've stripped down the gearbox (650 super rocket A10 STD box) and although all seems to look ok apart from the selector plate and spring which I have replaced, one of the selectors looks a bit of an odd colour. It seems ok but I thought I would ask if this is expected / normal.
Any thoughts please?
Thanks
there will be some discolouration, blueing usually as the fork is running in a gear groove and there will be some friction and rubbing especially if clearances not enough.
as the forks are heat treated to harden any reddish colour could be due to insufficient or worn out heat treatment. Also. if motor was left for a while with insufficient oil and in a damp area, there could be some staining from rust.
Thanks for the reply
The bike was stood for about 5 years at one point so that may well be the reason.
I stripped the box as it was difficult to come back down the gears, I did find a chewed selector plate which I replaced and I bought a new gear change spring too as that seemed a bit loose although the one that was in had parallel ends and the new one is slightly crossed over so quite a bit tighter. I got it from Draganfly who said that the older part had been superseded.
Can anyone advise what oil is best to put in these boxes?
Thanks
Hi I am stripping my gearbox down due to a bad whine from 2nd and mostly in 3rd so dont know what I will find when I strip it, but I have been told to use GP50............but I have always used EP80/90 in gearbox`s on my Triumph and Norton and I even got told this by the guy at SRM only today to use EP80/90 so that is what i am going to stick too,
Hope this helps
Mo
Hi Mo
Thanks for the reply, as I didn't get any replies until now I've put 20w50 to run it a little as I'm still sorting the clutch out but will probably drain and refill it when I've got it all working.
Good luck with the strip down, there's isn't much to them, certainly nothing like a modern box. The service sheets are good info too.
Regards
Thanks I will be needing some parts I think but as I say i am going to go back using this as it was what was recommended to me
Morris Golden Film AG90 gear oil. cheers Mo
Worth checking, but I was under the impression that EP oils should not be used where they can come into contact with some materials. This is because they contain phosphorus and sulphur compounds which are corrosive to yellow metals such as brass, bronze and copper. Typical materials found in BSA gearbox bushes.
Rich
Morris AG90 gear oil is non EP and is claimed safe with phosphor bronze bushes.
https://www.morrislubricantsonline.co.uk/golden-film-ag-90-gear-oil.html
Sorry, as owner of a single, rather than a twin, to intrude, but in my 1965 B40F gearbox I have Castrol EP90. I'm not sure what metals any bushes etc might be made of, as I've never been in there. Do you think I should change my oil to the Morris AG90?
To confuse matters, I see the Haynes manual recommends Castrol GTX 20W/50 for the gearbox as well as the engine.
Phil.
Hi Phil
Don`t think it will matter much...but if you want it will not hurt to put the Morris AG90 in...as Julian said this is a Non EP oil and is Claimed not to have the harmful Elements that break down Phosphor Bronze bushes...but there is also brass bushes that contain oil too...........so as I say use the morris AG90 oil don`t think you will be doing wrong..........and I would Not use Engine oil as with the way the gears are on a BSA or many other gearboxes come to that I would use a gear oil made for that job.
Having stripped down my A10 gearbox to find the layshaft and bushes well and truly goosed I tried to find out why. I have been told it was damaged by using the wrong oil. I found this hard to believe.
A simple trawl of the Internet confirms that EP oils are not suited to A10 gear box. I found this
Certain extreme pressure (EP) additives can chemically react with these softer metals, causing premature wear and even failure.
And goes on to say
Active sulfur in some EP additives reacts with the copper within the brass or bronze. Sulfur, when in contact with copper along with the presence of heat, forms copper sulfide. This simple chemical reaction can have devastating repercussions on the reliability of machines. In extreme pressure situations, copper disulfide can be formed. Both of these crystalline forms of copper are very hard and can cause abrasive damage to soft machine surfaces.
The damage to the bushes and layshaft looks like a hard sand like material has been added. This fits in with the text above. The main shaft bearings are in good condition.
I retrieved this text from https://www.machinerylubrication.com/Read/28958/ep-additives-effects
It is not unusual to find worn and scored layshaft bushes and layshaft journals to suit.
A lot look like the one in the photo below.
I think lack of attention to oil changes in the past also contribute to the problem.
The small diameter clutch end layshaft bush takes a lot of hard work given that all the power in 1st 2nd and 3rd is transmitted through the fixed layshaft pinion to the mainshaft sleeve gear.
I have attached pictures of my old layshaft and bush. They tell a sad story of neglect. I still find it hard to believe it could be the oil alone although several sources are telling me so. I am sure lack of oil changes contributed to this although I would have expected more wear on the mainshaft bearings.
years ago our local road race club took sponsorship from an 'upcoming' oil company , the race sponsored was the 250cc 2 strokes, to gain points for the championship you had to have their sticker on the fairing as you went over the line. one respected rider , with backing from a major sponsor used Silkolene without problems. when given the new oil he kept the stickers but passed the oil to others and carried on winning. another rider changed to the new oil, half a season later he retired from racing having spent his money and most of his brothers on 5 cranks and 2 pairs of crank cases...
some people reccomend the other oil, especially amongst the classic fraternity... personally, its always Castrol for me, never had any problems, Castrol or Silkolene for 2 strokes, modern 4 strokes Castrol or Silkolene or Motul, cheaper Chinese bikes my trade suppliers oil own brand.... I cant afford to rebuild customers engines due to poor oil quality.
taking other peoples opinions never interested me as they wont take responsibility if it goes wrong. my first job on a new purchase is a service with my oils, I know where I stand..