Speedo drive nut?

[brackenfel]

Dear All,
The gearbox is out and work has started on dismantling..
When the bike was running I noticed that the spedo drive cable filled with oil. Looking at the  parts list I see there should be a nut & fibre washer (65-3391/2). My bike has neither fitted (see pic below). As the parts list is a bit "generic" can anyone confirm that my (1961) bike should have these ?

As you'll see from the photo the grease-mad PO had a go in here as well! The only place I've not found any (yet!) is the engine....

Thanks,
Adrian

[trevinoz]

Adrian,
             You have the late type alloy drive which does not have a nut and fibre washer.
Only the brass drives did.
  Trev.

[RichardL]

Adrian

I just had to edit my post-in-the-works after seeing Trev's. The funny part is, my assumption that Trev would know the answer was from before I saw his post. So, Trev, is this an A10 part? Did A65 use a similar, longer part?

I just spent what seemed a lifetime on this part of my bike, so I'm jumping in here. Without being expert in all of the A10 years and other BSA models, it appears to me that too much of the speedometer driven gear bush is sticking out from the case. I think someone else (Trevinoz?) will probabaly jump in and name the exact model. With that much shoulder sticking out, a washer and nut will do no good. Also, mine is brass, but I suppose that might have changed over the years. 

Richard L.

[trevinoz]

Richard,
                Definitely A10. The A65 used a similar type.
I think the alloy drive was used post 1960. The clutch cable adjuster was also removed from these boxes hence the cable stop being a shouldered hole without slot and thread.
  Trev.

[RichardL]

So, if it wasn't intended for a nut and washer, how did they keep oil from seeping past the bush? Is there an o-ring on the later models?

[trevinoz]

Richard,
              I think so.
I used an early drive in my late box as the alloy one was buggered by a previous butcher.
  Trev.

[RichardL]

Adrian,

I don't think we actually addressed your original issue, that is, oil in the speedo cable. The nut and fiber washer actually have nothing to do with that. The means that BSA intended for keeping oil out of the speedo cable was to spiral cut the shaft of the driven gear such that it pumped the oil back towards the gearbox. You can see this spiral cut at the attached link, where I was showing the difference in two types of driven gears (a difference that cost me some money and headaches). Ultimately, I think it is possible that oil could wick all the up to the speedo. The best prevention is probably using a cable in good condition.

Richard L.

http://www.a7a10.net/forum/index.php/topic,2242.msg14437.html#msg14437

[alanp]

Manosound, thanks, I was also wondering how the oil drips were getting out of the box and on the floor. The cable casing was split at the gearbox end so I've just bought a new one from Speedograph Richfield.
Alan

[brackenfel]

Many thanks to Richard Alan & Trev..
The later type would probably be right as so far most parts of my bike seem to point to them all being from the post '60 era which is encouraging.. Who knows , most of the big bits may have even left the factory at the same time!! (maybe optimistic though!!)

I have a new speedo cable ready, I'll try that & see how things go..

I've also looked at the inner case & found that the kickstart stop is loose and chewed up and that the kickstart ratchet pinion is badly worn so that's a couple more bits I'm going to need..

Thanks again for all the help - appreciated..  It's amazing how much you can learn here!!!

Adrian

[trevinoz]

Adrian,
             Unfortunately, when the quadrant stop becomes loose in the inner cover, it chews the hole out into an oval shape which becomes a bit of a job to repair satisfactorily.
               Trev.

[brackenfel]

Trev,
Oh dear !! I'll have a look later but I bet mine will be less than round... I have a good friend who's an ex Rolls Royce engineer, maybe he can suggest something..
Thanks,
Adrian

[orabanda]

I have dealt with the flogged out quadrant stop by drilling out the hole until round, then machining a replacement stop, to suit the new size. To stop it happening again, I add a shoulder (like a washer) to the stop; this bears on the inside surface of the intermediate section of the gearbox. This prevents the stop from rocking, therefore it is less likely to come loose, and the flogging - out issue is done with.

I have also found that gearbox oil will leak out of the speedo drive over time (not surprising given that the reverse scroll on the spindle will only work when it is rotating). Therefore, I machine inside the brass carrier, and insert a couple of o-rings; this stops it farting in church!

Richard

[1660bob]

Hi, seems we all have the same problems...... I have also noticed the kickstart stop is past it.The problem here is that it has to endure high shock loads from time to time as the kickstart reaches the end of its travel.The shoulder on the stop itself is too small a diameter and soon digs into the case alloy, the stop loosens itself and starts to hammer out the oval hole mentioned above......
I have not had time to rectify this one yet, but my thoughts so far would be to turn up a new stop from larger dia bar (S/S) with a "Flange" to increase the surface area against the casing.I think there is just enough room to miss the quadrant edge as it sits off the alloy due to the flange on its own bush(67-3151).The casing damage (ovality)could be carefully reamed out and the new stop turned with a slightly larger shank dia to suit the cleaned up case( a nice, close nil clearence fit, but no interference).Obviously, the larger O/D shank will have a small shoulder where it meets the thread, and this shoulder will have to be cut back to avoid it interfering with the nut/ washer as they are tightened up.A good,solid, thick washer (not one of those pitiful s/s "standard" thin things) to cope with bridging the slightly larger casing hole, a lick of good grade Loctite on the thread (when are you going to take this out?) Beefier all round and good for the next 50+ years I reckon. Thats my suggestion, Regards, Bob