molyslip in gearbox

[Dynamo Regulators Mike]

My gearbox makes a lot of noise in 2nd & 3rd gears, just like a lot of them do to a greater or lesser degree. Have often wondered if fitting needle rollers would help this. If 8 or 10 % of power is lost in these ratios and the loss is reduced by fitting the Torrington bearings (source Roland Pike autobiography notes), then some of the energy will surely be lost as noise and vibration, and the oil does not seem to get very warm at all.
But is a much easier improvement to be had by adding Molyslip g'box additive? Can't see it could do any harm and it might do some good. Anyone here tried it?

[bsa-bill]

Yep and it still whines in third

All the best - Bill

[Dynamo Regulators Mike]

So did it cure noise in second then Bill.

[beezalex]

I seriously doubt anything but sawdust is going to help the whine.  The source is usually either a bad bearing or wear in the gears.  The mainshaft ball bearings will make noise themselves while the increased clearance from worn layshaft bearings will make the gears whine.  Of course, excess clearance from the gears themselves being worn will make them whine as well, which is typically the case for 2nd gear...

[Dynamo Regulators Mike]

If Molyslip miay as well be heavy duty snake oil what grade of sawdust is recommended?
All bearings and bushes were renewed just a few thousand miles ago. Gears looked pretty good for wear but then it would presumably only take a couple of thou to make a difference. Another possibility is a slightly bent shaft I guess.

[groily]

Chez moi, only 3rd whines under light load and I've got used to it. Started after I changed the top gear (mainshaft) pinion and made a new sleeve gear bush: non-matching pinions was the result and a noise was probably inevitable. Second is OK, but too low as I often say, not its fault. Haven't tried snake-oil or Molyslip but I guess they may help. It's only a thou or two here or there, as Mike said. I doubt the noise consumes much of the power!
More cheerfully, 3rd on my B31 is absolutely silent by comparison. Could always change the guts round I suppose, to put the lower stressed bits in the more stressed box . . . but think I'll preserve the single, as it runs like a new bike . . .  Not, in my oily world, a big worry - touch wood.

[beezalex]

I only use oak #000 sawdust...

But seriously...even if you probed the clearance between the gears with a feeler gauge, I don't think you can say at what point it will start making audible noise, because it's aslo dependent on load, speed...the type of helmet you're wearing...  Maybe someone knows, but I sure don't.

I rebushed the gearbox in my A10 and replaced the bearings a couple of years ago to get rid of the whine in 2nd gear.  It works exactly the same now and makes exactly the same noise.  I don't think it takes much wear on the gears as once the involute shape is compromised, the teeth all come together with a small "clap".  All you can do is get to 4th gear quickly.  No whine there.

[BSA_54A10]

Fit the lower gear side car sprocket.
The 3rd will be too low and you will pop it into top a lot sooner ;-)

[fido]

Ah, I had not thought about the noise being just in low gears. I thought it was always noisy but drowned out by the exhaust at higher speeds. I bought some molyslip for mine but have not got round to putting it in yet.

[Dynamo Regulators Mike]

I will try adding molyslip as well, unless any real horror stories turn up in the meantime.

Interesting that groily changed the sleeve (output) gear bush and suffered whining. Mine too was changed and fitted to a nice freshly  ground mainshaft surface. I am now wondering if a fraction too little clearance here would add to the whining. It doesn't always seem to get too much oil up there (there are sometimes signs of rust on the shafts). Maybe thats where a solid lubricant film may pay dividends.

Will leave any needle roller experiemnting to a later date.

 

[bsa-bill]

Mine only ever whines in third, could well be the layshaft every one I've ever seen has been scored at the ends.
I renewed ths bushes but don't think it could make much difference/

All the best - Bill

Sorry if you read this elsewhere - I replied to the wrong subject 

[groily]

Had to change the mainshaft gear too Mike, with it's adjacent pinion, as the dogs had worn down and top wouldn't stay engaged. But didn't change the layshaft bits for lack of them. Sleeve could be a bit tight though, and under-oiled, it's a good point - although in that case I'd expect some sort of noise in neutral too wouldn't I? I tried to make the bush as good a fit as I could after making good the oval mainshaft, and I made it in one piece rather than the two often found in there. Original problem was that the sleeve gear bushes weren't properly in place, someone had hammered the outer one into the gear from the outside to try to get the clutch on, the inner bush was forced a wee bit proud on the inside, and so the top gear dogs wouldn't fully mesh, so wore out. And there were all sorts of associated things not right at the kickstart side in consequence of this misalignment - bit of a foul up really and put all sorts of stress on everything. Says something for the box that it stood it for however long.

[69Bonni]

My Wife wines a lot when i shove off out on the bike!

However i use Molyslip in My Bonnie and in my A65T, with no ill effects! I originally put it in the Bonnie to help with a wining Layshaft and it did help. I dont think it will cause you any problems Mike and in my mind can only be better, Helping all that gear train to slide around easier.

The only place i wouldnt want it to be is in the Primary chain case!!!!

Go with it Mike, it can only help short of stripping the box again, maybe the next time you take it all down have another look through the box.

Regards

Steve

[mrshells]

mine doesnt whine ????
whats wrong ??????????

[Dynamo Regulators Mike]

Hi
Finally got around to changing the gearbox oil and adding Molyslip.
Conclusion: Not all snake oil should be tarred with the same brush.
The improvement is amazing. The box is much quieter out and about in 2nd & 3rd on a 70 mile steady run yesterday, lots of intermediate gear running through the 30 mph villages to verify.
The ride was also improved in another way. The fast boys / nutters weren't out in force per most Sundays on the local minor A roads. There was much rain overnight and the odd daytime shower. Poor dears stayed inside presumably.
But us from Hants BSA Branch did not get a drop.
Wicksteed next weekend and another 300 miles.