The BSA A7-A10 Forum

Technical => Clutch, Primary, Gearbox => Topic started by: peter on 05.07. 2017 19:51

Title: Mainshaft gear separate from main shaft A10
Post by: peter on 05.07. 2017 19:51
On my Goldflash 1954 swingarm the transmission has a defect, for this reason I have to separate the main shaft gear No. 67-3191 from the mainshaft No. 67-3330. How to do this without the locating ring No.67-3101 to destroy? Is the gear pressed onto the shaft?
The main shaft is crooked too so I must have a new one, knows one where I get one ?
Best thanks in advance for your help.
Peter

Title: Re: Mainshaft gear separate from main shaft A10
Post by: JulianS on 05.07. 2017 20:15
Support the pinion then press the shaft through it from the short end. 67 3101 should not be damaged doing this.

The pinion can be very tight. You may be able do it using a copper mallet to drive shaft through or if very tight you may need to use a hydraulic press  to pop it off. Using a press it will probably release with a bang.

New mainshafts are available from the better dealers. You often see used ones on ebay. Dont use one from an RRT2 Gold Star box, it will not fit the sleeve gear.
Title: Re: Mainshaft gear separate from main shaft A10
Post by: duTch on 05.07. 2017 23:04

 I had success by sliding the shaft down a length of pipe with a washer big enough to protect the dogs, had some kind of fastener with a big enough head and  a washer to protect the shaft end(with nut on), used a 10Lb hammer on a lump of hardwood to drift it. The pipe was a bit long, so stuffed some rag up the bottom to cushion it if/when it popped off- seemed to go easy enough

 Much the same concept in reverse to add the replacement
 
Title: Re: Mainshaft gear separate from main shaft A10
Post by: kiwipom on 05.07. 2017 23:59
hi Dutch, nice bit of bush mechanics, well done, cheers
Title: Re: Mainshaft gear separate from main shaft A10
Post by: duTch on 06.07. 2017 03:56

 Thanks KP- I won't let it go to my head though as I'd be surprised if it's not a well used method, just went through the detail for anyone who hadn't done it *conf*
Title: Re: Mainshaft gear separate from main shaft A10
Post by: peter on 06.07. 2017 13:55
Support the pinion then press the shaft through it from the short end. 67 3101 should not be damaged doing this.

The pinion can be very tight. You may be able do it using a copper mallet to drive shaft through or if very tight you may need to use a hydraulic press  to pop it off. Using a press it will probably release with a bang.

New mainshafts are available from the better dealers. You often see used ones on ebay. Dont use one from an RRT2 Gold Star box, it will not fit the sleeve gear.

Hello Julians,
I have a 50 To hydraulic Press so i will have now problem with your metode.
I was looking for a new axle in Ebay but there it had just crumbled ones.
Do you know the name of a good trader who sells new ones?
Best regards Peter

Hi duTch,
your method is also to make, but I have a press, thanks vor your advice.


Title: Re: Mainshaft gear separate from main shaft A10
Post by: JulianS on 06.07. 2017 14:17
Draganfly Motorcycles are listing them at about £140.

https://www.draganfly.co.uk/index.php/accessories-a-misc/product/14349-

Title: Re: Mainshaft gear separate from main shaft A10
Post by: Topdad on 06.07. 2017 14:43
I bought a new one from *********  some yrs ago and from that experience ,incidentally I've just set it aside for the second time due to it being incorrect size after being supposedly resized  , I'd check every measurement  prior to fitting ,twice !!
Title: Re: Mainshaft gear separate from main shaft A10
Post by: JulianS on 06.07. 2017 15:27
What is the damage to your mainshaft? Usually quite robust. Some damage around the keyway is also usual but unless severe the ahft remains usable. The pinion 67 3191 is often worn causing jumping out of third gear.
Title: Re: Mainshaft gear separate from main shaft A10
Post by: Topdad on 06.07. 2017 16:26
Julian, is that directed to me or Peter ?
Title: Re: Mainshaft gear separate from main shaft A10
Post by: duTch on 06.07. 2017 17:32

 
Quote
Do you know the name of a good trader who sells new ones?

 I haven't bought anything from either of these but maybe worth a try, others may have experience;

 http://www.auto-cycle.co.uk/ (http://www.auto-cycle.co.uk/)

  http://www.auto-cycle.co.uk/parts.htm (http://www.auto-cycle.co.uk/parts.htm)

 or a bit closer to home;

 http://en.vintage-motorcycle.com/index.php?language=en&site=1 (http://en.vintage-motorcycle.com/index.php?language=en&site=1)
Title: Re: Mainshaft gear separate from main shaft A10
Post by: JulianS on 06.07. 2017 17:58
Julian, is that directed to me or Peter ?

Sorry it was for Peter.
Title: Re: Mainshaft gear separate from main shaft A10
Post by: JulianS on 06.07. 2017 18:03
Auto cycle are good, I have bought quite a bit of NOS gearbox stuff from them , and bought a newly made RRT2 mainshaft from them a few years back.

The only issue with it was that the pinion was a very tight fit - tighter than the original shaft.

I think all the repros come from the same manufaturer and are made in small batches.
Title: Re: Mainshaft gear separate from main shaft A10
Post by: morris on 06.07. 2017 22:27
Ordered one at De Groot some time ago. Superb quality and straight fit.

https://www.degroot-bsa.nl/index.php?route=product/product&path=51_60&product_id=2558
Title: Re: Mainshaft gear separate from main shaft A10
Post by: peter on 08.07. 2017 15:00
I could remove the gear from the mainshaft ( Press)
The cause of damage:
The ball of the clutch push rod has fallen out and could get somehow to the rear and there between two gears. Now the mainshaft is a little unbalanced it results in a 0,3mm unbalance. A gear is missing a tooth and two other gears have heavy damage. I have three replacements gears so I could repair the gearbox when I know exactly what to do with the mainshaft.
Thanks for the advices and  parts- links.
Best regards
Peter
Title: Re: Mainshaft gear separate from main shaft A10
Post by: duTch on 08.07. 2017 22:46

 
Quote
.....The ball of the clutch push rod has fallen out........

 Do you mean the push rod adjuster?

 Sounds yukko, and the shaft is 0.3mm bent? That equates to ~0.012" (12 thou?) ?
Title: Re: Mainshaft gear separate from main shaft A10
Post by: peter on 10.07. 2017 21:14
Yes, it was the adjuster, I had written it wrong. Now I have ordered a new mainshaft from degroot-bsa.
It's difficult for me I can not write English so well.
kind regards Peter

Title: Re: Mainshaft gear separate from main shaft A10
Post by: peter on 12.07. 2017 19:55
Hello again,
The gearbox-housing halves were screwed together with paper seals, is that important or can I only take sealant?
The photos show the two trough the ball demolished gears.
kind regards
Peter
Title: Re: Mainshaft gear separate from main shaft A10
Post by: JulianS on 13.07. 2017 11:38
I use gaskets plus sealant - the inner cover gasket does have a slight effect on clutch alignment and also an effect on clearance between quadrant and camplate and layshaft float.

The outer cover gasket can effect clearance between selector and quadrant.
Title: Re: Mainshaft gear separate from main shaft A10
Post by: Topdad on 13.07. 2017 13:46
Nasty , ripped those gears apart and god they are tough !
Title: Re: Mainshaft gear separate from main shaft A10
Post by: coater87 on 13.07. 2017 16:34
Nasty , ripped those gears apart and god they are tough !

  *eek* I was thinking the exact same thing!

 I would really look closely at every part of that box looking for any other damage, including the case. That took a huge amount of force.
Title: Re: Mainshaft gear separate from main shaft A10
Post by: peter on 19.07. 2017 15:29
I again,
exept the axles and the gears is all ok, the gearbox has no damage.
In the pictures you can see the gear with the missing tooth and how I press this out.
JulianS had told  me that I need the gaskets and so I have ordered both,  thank
a lot for your advice.
Kind regards Peter
Title: Re: Mainshaft gear separate from main shaft A10
Post by: Sluggo on 19.07. 2017 19:41
Sounds like the issue was sorted and success! just want to add when removing or replacing gears or parts with an interference fit that Heat and cooling IS your friend!  *smile*

Of course a large Hydraulic press is VERY effective!

When pressing or removing a pressed on gear, Warm the gear itself with a torch NOT TOO MUCH, but warm it and wrap the shaft with a towel soaked in COLD water, and it can change dimensions by several thou" and separate quite easily.  Same in reverse,  Heat in an oven the part you want to expand, and chill in the freezer what you want to minimize.
Gears and trans shafts especially are very fiddly so have seen a few items break or crack when being pressed or taken apart,
When manufactured they are (generally) made out of a high quality steel and inside is somewhat malleable and soft, but the exterior wear surfaces receive a heat treatment.  The depth of which varies.  BSA were also a metals company and in my view,, much of their materials WERE built to a price but tended to be pretty good stuff compared to Norton-AMC and others. 

I have seen some videos (Cough cough) that show some rather agricultural practices with gearbox rebuilding (Wont name names) but I shudder every time I think of it when I see Bodgers heating up engine or gearbox cases with a torch willy-nilly and then WHACK! beat in bearings with a resounding THUD with implements of destruction.
Cast aluminum is a particular entity and not meant to be heated and distorted in such manner.
CAREFUL and slow application of heat (Suggest start at 150 deg F., then up to 200 deg F , then 300 deg F  ALLOW to normalize in each stage) then remove, press in or remove bearings or bushes, THEN wrap with a towell or replace back in Oven and allow to cool over several hours SLOWLY..  Expecting a alloy casting to hold tolerances 70 years on and then beating the Bejeezus out of it is unrealistic
Title: Re: Mainshaft gear separate from main shaft A10
Post by: peter on 31.07. 2017 13:47
Hi ,
 I have noticed, the" layshaft bush closed end" is worn, I have ordered a new one now the question:
cam I press out the old one, should I cool the new one and warm the casing?Has one  already done like this?Are there tricks for this work.
Thanks in advance,
Peter
Title: Re: Mainshaft gear separate from main shaft A10
Post by: chaterlea25 on 31.07. 2017 19:33
Hi Peter,
Heat the casing and tap the old bush out,
I have found that the layshafts are usually worn as well
So either a new shaft or machine the old one undersize and make new bushes to suit

John
Title: Re: Mainshaft gear separate from main shaft A10
Post by: bikerboy on 16.08. 2017 22:56
Sometimes I long for the old days when all we had was a hammer, a screwdriver and three spanners  *smile*
Title: Re: Mainshaft gear separate from main shaft A10
Post by: bsa-bill on 17.08. 2017 19:47
Quote
and three spanners  *smile*

three BSA spanners fitted 7 or 8 nut sized if I recall (come to think about it that covers just about all on an A7/A10)
Title: Re: Mainshaft gear separate from main shaft A10
Post by: Topdad on 22.08. 2017 11:09
Bill ,like wise Mk2 Jags ,you'd strip one out with 5 or 6 ring spanners  *smile*
Title: Re: Mainshaft gear separate from main shaft A10
Post by: peter on 16.09. 2017 21:56
Hello colleagues,
this week I put the transmission together. I bought new axles bei de Groot. I found the gears on the Internet they were offered by John Shynn from Sutton on Sea GB, he had about 40 gears , 4 axles und some others parts offered, I took the opportunity and bought all! I drove with the Bike (Yamaha Virago) to England and took all the Parts ( round trip about 1700 km 5 days) John is a very friendly Biker, it was a nice meet.One day I stayed in Skegness a nice place at the seaside.
Today I did a test ride the gear work as they should everything is OK.
Greetings Peter

 
Title: Re: Mainshaft gear separate from main shaft A10
Post by: BSA_54A10 on 17.09. 2017 08:15
When pressing or removing a pressed on gear, Warm the gear itself with a torch NOT TOO MUCH, but warm it and wrap the shaft with a towel soaked in COLD water, and it can change dimensions by several thou" and separate quite easily.  Same in reverse,  Heat in an oven the part you want to expand, and chill in the freezer what you want to minimize.
Gears and trans shafts especially are very fiddly so have seen a few items break or crack when being pressed or taken apart,
When manufactured they are (generally) made out of a high quality steel and inside is somewhat malleable and soft, but the exterior wear surfaces receive a heat treatment.  The depth of which varies.  BSA were also a metals company and in my view,, much of their materials WERE built to a price but tended to be pretty good stuff compared to Norton-AMC and others. 


Don't want to sound like I am picking on you but the max a 1 1/2"  steel gear can expand before undergoing a phase change is 0.0002" and that would be at dull red heat .
While the idea you propose is sound, the numbers are not.
Because stuff on the web persists for ever we should be careful to ensure what we print is factually correct .
When you heat the gear the gear does in fact expand and the tiny expansion is generally sufficient to break the bond between the oxide layers on the gear & the shaft which is what is locking them so tight together.
To get 0.002" difference the shaft would need to be in liquid nitrogen & the gear red hot.

Holding aluminium - silicon alloys at temperatures over 200 deg for extended times ages the alloy an promotes precipitation of complex silicon compounds with impurities, particularly iron at the grain boundry region rendering the casting stiff & brittle.
If you are going to heat it then on a flat surface strait up to 450F and cool quickly but do not quench.
 Quenching causes the casting to distort due to differential expansion between the hot & cold sections.
Title: Re: Mainshaft gear separate from main shaft A10
Post by: Sluggo on 17.09. 2017 09:28
Trevor, reread what I wrote,,, you quoted 2 very important dimensions first at the 4 decimal point which I can change by holding in my hand or breathing hard on it,,, and then the 3rd decimal point which requires a bit more heat.

Secondly then you talk about alloys, Are you talking alloy castings or gears and shafts made out of steel?    The method I describe was a method for gears and shafts I was shown in Aviation school with FAA approved tech materials and using a Cessna service center tool, I can assure you thats a time proven method with extensive scrutiny.  I summarized the technique as applied to a motorcycle part, and generally a hydraulic press would be sufficient, but I was trying to illustrate what heating and cooling techniques can do.

I *THOUGHT* I was competent with a Micrometer and worked in Aerospace as well as vehicle fleet maintenance for over a decade when I went back and took some more classes to get my federal Aviation license.  In one of the classes one of our instructors *RETAUGHT* us proper use of a caliper and micrometer.  Despite working for some of the biggest names in aerospace I learned I was using Micrometers wrong.  In which case there is a LOT of people reading them wrong.  But ol' Harold taught us a valuable lesson.  One of which is how even a little bit of heat can change dimensions.   The lesson was Mic'ing a crankshaft journal and a rod bolt.  Then we had to hold the parts in our hands during part of the lecture.  After 5 minutes we had to remeasure.  I would suggest you or anyone else try it with a Micrometer (with up to 3 decimal point measurements  IE:   0.000) you will find a surprising difference in measurements.

Now the same lesson with a caliper going to 4 decimal point.  Most modern digitals are 0-5-0 for the 4th point but some can actually read 1-9.   I can breathe heavily on a part and change that 4th point.

Now, do the same measurements with gears, bearings or shafts with one part in the freezer for 10 min and the other in a oven at 250 deg F/121.11 C and again check dimensional changes ID & OD.  I am certain you will find the measurable differences remarkable.  Its worked very well for me over the years.
Title: Re: Mainshaft gear separate from main shaft A10
Post by: peter on 09.10. 2017 19:02
Hi,
before I forgot to mention, I dismantled all parts without warming, in the assembly I warmed the Layshaft gear, but only little, about 120° Celsius, the Layshaft I cooled in the refrigerator about 4° Celsius then under my press all slippt in without problems.

regards Peter


 
Title: Re: Mainshaft gear separate from main shaft A10
Post by: Sluggo on 09.10. 2017 22:17
Peter, that should do it,  You just forgot to mention one thing (Assuming there is a spouse here) Is unless your workshop is very well appointed is do this when the MRs is not at home and always clean up the evidence.
I often will open some potporri, light some incense or put some vanilla extract on some tin foil in the oven afterwards.

Installing bearings in engine cases is often quite fragrant.  I used patchouli oil and my wife came home and accused me of killing some hippy chicks.  Wanted to know why the house smelled so strong.
Title: Re: Mainshaft gear separate from main shaft A10
Post by: Greybeard on 10.10. 2017 11:06
I had an old Land Rover that had its parking brake drum just behind the gearbox. Gear oil would leak onto the shoes. I would wash the shoes in petrol, dry them off and finish by baking the shoes in the oven. A bit smelly!