The BSA A7-A10 Forum

Technical => Clutch, Primary, Gearbox => Topic started by: BSA500 on 20.01. 2012 20:11

Title: Sleeve gear bushes replacement
Post by: BSA500 on 20.01. 2012 20:11
Hi,
My sleeve bushes are in need of replacement-oil everywhere,clutch moving around etc. I have a couple of spare gears so I am trying to remove the old bushes and then put in the new. I am using the tool usually used to draw up the fork legs so its very tough but the bushes just will not budge.What is the general method everyone uses heat?violence? or......

Thanks Andy(who has enough dealing with riding every day,dead dynamo and mystery vibration prob the clutch :!)
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 20.01. 2012 20:34
I've done this job and took some pics which if no one beats me to it I'll post them up

From what I remember the bushes I took out were split and not that hard to out but pattern replacements were not split but went in easy enough using a vice

Title: Re: Sleeve gear bushes replacement
Post by: trevinoz on 20.01. 2012 21:44
I machine the bushes out in the lathe.
 
  Trev.
Title: Re: Sleeve gear bushes replacement
Post by: Brian on 20.01. 2012 21:54
Depending on what equipment you have available to you there are a few ways to remove them.

Use a lathe as Trev suggested which is what I do.

If you dont have a lathe you can use a threading tap, find one that screws into the bush and then knock or press it out.

If you dont have any of that stuff a hacksaw blade held in the hand will work. Just carefully slot them until they come loose. The gear is hardened so at worst you will only scratch the gear if you go too deep.

After you have fitted the new bushes, making sure you have lined up the oil holes in the inner bush, you may have to ream them to size. If they do need reaming then once again if you dont have a reamer then you will have to take them to a engineering place. Reaming the bushes is a simple job so they shouldnt charge much to do it.
Title: Re: Sleeve gear bushes replacement
Post by: Goldy on 20.01. 2012 22:02
If you slide a hacksaw blade through the bush and then assemble the hacksaw around it, you can saw partly through the bush so that when you try to remove it it will collapse inward. all the best Goldy.
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 21.01. 2012 12:27
Used the hacksaw trick one out already. But these bushes are steel backed *eek* which makes it a little more interesting. What is the running clearence of the shaft when its reamed?. Also any one know any good engineeering shops near Tonbridge kent.
thanks Andy
Title: Sleeve gear bushes replacement
Post by: KiwiGF on 23.01. 2012 07:23
Here's some pics of tools I made up to remove and replace the sleeve bushes - the most important bit is the small stepped (shiny) colIar which is a fairly good fit inside the bushes and sleeve gear.

I got the new bushes  from Draganfly.

It sounds like you will have got the old bushes out using the hacksaw method by the time you see this - but I thought anyone searching the forum might find these pics useful. My bushes pressed out quite easily using 10mm studded rod, but as the pic shows one was installed slotted for some reason.

The old bushes had 015 clearance on the mainshaft but I do not know what effect that had on the gearbox leaking/whining etc as I have not run the bike yet. I noticed the excess clearance when removing the clutch.

As regards the correct "new" bush clearance, I've done mine at just over 001, but up to 002 would prob be OK.  I think there is a BSA document on plain bearing clearances somewhere on the net. I'll try to find it.
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 30.01. 2012 20:52
Right the bushes are out and they were both steel backed and one was stamped with VP. I reckon they are BSA supplied ones and also one was split lenghtways. I have decided to bite the bullet and get a hand reamer and pratice on an old sleeve gear then do it myself. Just to check the mainshaft dimension is about 0.810 thou?.The reamer size I would need is 25/32-27/32(£18.00 all in from Tracy tools cheaper than paying a workshop)  Good idea??
Title: Re: Sleeve gear bushes replacement
Post by: Pilgrim on 31.01. 2012 19:55
Hiya,
Don't know if this helps?
www.mistgreen.com/service.htm
look for service sheet 702
Cheers.
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 31.01. 2012 20:31
Thanks for that. It seems to suggest the shaft itself is 0.810 so the reamer I was looking at is the right size range. Hang on reading another thread suggests the shaft measures 0.75 but the old sleeve gears I have are approx .810. can some one please measure the mainshaft of a swing arm gearbox pretty please before I buy a reamer.
many thanks Andy
Title: Re: Sleeve gear bushes replacement
Post by: wilko on 31.01. 2012 21:45
Just take it to a local engineering shop? No point in buying a one use reamer.
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 01.02. 2012 05:04
I'll check a mainshaft for size later tonight but I reckon you should buy and fit new bushes before buying the reamer as you might not need to ream the bushes, especially if your shaft is worn a bit under?

Added an extract from the 702 service sheet as mentioned in a post above, with the "pinion gear" bush tolerance at 0.812/0.813.
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 01.02. 2012 08:45
Its actually cheaper to buy the reamer than take it to a workshop(if one even existed round here). Also seeing as I use her every day for work I can do the work to my timescale. KiwiGF if you wouldn't mind that would be great.
Andy
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 02.02. 2012 09:40
My mainshaft where it fits inside the bush is 0.809" diameter

Did I really just say that:-)
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 02.02. 2012 12:34
Thanks your a star that means the reamer I was going to buy will be right.
Andy
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 03.02. 2012 21:06
Most likely BSA chose 0.812/813 as 13/16 is midway at 0.8125 so they could use a std 13/16 non adjustable reamer to get the reqd bush dia and machine all the shafts slightly under 13/16 to get the necessary clearance

The shaft you have is probably worn so you might want to make the bush slightly under 13/16
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 04.02. 2012 09:09
The reamer I have chosen go's from 0.78 to .84 so should have that covered  *smiley4*
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 18.02. 2012 17:53
Well the fun never ends does it. Just installed the bushes and found out the short bush of the pair is,well,short by 10 mm. Of course this means there is a gap. My question is would that really be a problem as I have it planned to do the gearbox next weekend and cannot afford to order replacemnet bushes in time reasons.
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 19.02. 2012 06:58
If you look at my earlier pics the bushes are the same length and I would not use them if they have been supplied wrong

What does the supplier say about the bushes they have supplied?

Draganfly supplied mine ex stock
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 19.02. 2012 10:59
These were from Draganfly and every order for parts from them recently have been wrong. The rocker feed that took 2 months then was for a b25 to ordering 4 sprocket nuts and paying for them and getting only one. As for the bushes my next door neighbour an ex engineer said it should be ok if the shaft is supported each end. As I said before next weekend is one of the few times I can have the car for work while I repair the box so it has to happen. Draganfly are not open weekends so I would have to wait until Monday to contact them. On the website it states you should have a short and long bush so I assumed that was right it seems not. It would take to long to get new bushes and meet my deadline. Ho hum
Title: Re: Sleeve gear bushes replacement
Post by: bsa-bill on 19.02. 2012 13:34
I'm pretty sure mine had one long one short
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 19.02. 2012 19:23
bsa-bill,
was there a gap between the bushes when installed. Really wahat I am asking is there an issue with this gap. I myself cannot see a real problem with this?
Title: Re: Sleeve gear bushes replacement
Post by: bsa-bill on 19.02. 2012 20:37
I would think a gap would be good, a little oil would always be in there
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 19.02. 2012 20:40
Yep I like that idea as well. *smiley4*
Title: Re: Sleeve gear bushes replacement
Post by: trevinoz on 20.02. 2012 03:15
As Bill said, that's the way they were.

  Trev.
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 20.02. 2012 08:18
I know you are going ahead with a gap but out of interest what part numbers did you order?

The part no for my 56 s/a GF is 2 off 67-3073, same part no for both bushes but one is drilled according to the BSA parts book, but both bushes were supplied undrilled.
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 20.02. 2012 08:48
Looking on Draganfly website and using the list of parts the numbers were 67-3073 and 67-3080.
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 20.02. 2012 09:18
Well I reckon 67-3080 short bush is correct, either the 54-57 BSA parts book is wrong or bsa shortened the bush on later models.

I'm now thinking I should have ordered using the Draganfly parts diagram myself!
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 20.02. 2012 10:05
Maybe but I doubt it really makes much difference as long as the clearance is correct. Why didn't BSA just make it one long bush?
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 23.02. 2012 22:54
Had an email from Draganfly which helps explain the different bush lenghts.....

Hi Andrew, from 1960 the A group gearbox was indeed fitted with two of the
67-3073 long bushes. Up to then, the bushes you ordered were fitted. Should
not be a problem though.
Cheers, Mick.

I have started the strip down tonight and will be pulling the gearbox apart tomorrow evening. Fingers crossed. Oh the play in the shaft is horrible.
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 24.02. 2012 20:53
Got the box apart and guess what the bushes are the long and short type. Also the play was awful but on measuring the shaft was 0.812 and the worn bush 0.816 only 4 thou *eek*. Still it does need doing so we will see how it is afterwards.
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 29.02. 2012 12:37
Done. The first measurements were wrong the shaft was .809 and the old bush 0.816. New one is in, and a vast improvement some vibration still but no snatching from the primary chain.
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 01.03. 2012 09:24
Tempting fate here all seems fine (whispering now )the box does not leak shhh
Title: Re: Sleeve gear bushes replacement
Post by: muskrat on 03.03. 2012 06:37
Did you put any oil in? ;)
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 03.03. 2012 10:50
Cheeky sod. Yes I did 80/90 but I have used 140 before now.
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 18.04. 2012 17:17
Update-replaced the primary chain as its well past its sell by date and noisy. Guess what yep the play is back in the clutch large amount of up and down play. WTF!! is going on here. Any other suggestions? the gearbox sprocket does not move so I am ruling out the main bearing.Surely the bushes cannot have worn out in one month can they???. God I wish I had some beer, and on top of it all work is being a pain in the a**e as well. I have got my health (still want a beer).
Andy
Title: Re: Sleeve gear bushes replacement
Post by: muskrat on 18.04. 2012 20:58
 It must be in the clutch bearing. What type of clutch? Most will wobble a bit even when new.
Cheers
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 19.04. 2012 11:34
Its the four spring type with the roller bearings. Its not a wobble as such more an vertical up and down and quite a lot could it still be the bearings?
Title: Re: Sleeve gear bushes replacement
Post by: muskrat on 19.04. 2012 13:28
Could be if the rollers are the wrong size or the bearing surfaces (ID of chainwheel or center adapter) are worn. Is the center adapter a good fit on the taper?
Cheers
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 19.04. 2012 16:33
The rollers are about twenty plus tears old so they may need replacing  *smiley4*. What I will do is strip it down and check for play in the bearing and shaft and hope its the clutch as it the far easlier to fix.
Title: Re: Sleeve gear bushes replacement
Post by: Topdad on 19.04. 2012 17:21
Andy, just a thought ,has you have changed the p/chain you didn't adjust it to  tight ? easy to do and I beleive that'll kill the bearings double quick although I hope its just the cluth rollers, best wishes BobH
Title: Re: Sleeve gear bushes replacement
Post by: Triton Thrasher on 19.04. 2012 18:10
Andy, just a thought ,has you have changed the p/chain you didn't adjust it to  tight ? easy to do and I beleive that'll kill the bearings double quick although I hope its just the cluth rollers, best wishes BobH

It can become too tight when the rear chain pulls the gearbox back.
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 19.04. 2012 22:26
Nope both the primary and rear chains are the correct tension.
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 20.04. 2012 20:54
Shows how often I do this stripped down the primary side and back together in 1 hour 10 mins. This was clutch off and the inner primary. Conclusion the bushes are toast in under a month. Were they made from cream cheese??. Got them from Draganfly and as I have said before I seem to have problems with late delivery,wrong parts and missing items. I did drill in oil holes and the shaft was wobble free when I put it together. I shall have to do it again but I will try C&D Autos this time. Any other ideas/pointers/free beers *sad2*
Title: Re: Sleeve gear bushes replacement
Post by: Triton Thrasher on 20.04. 2012 21:29
I'm told it's easier to make wearing parts from free machining brass than from phosphor bronze, aluminium bronze or oilite, but it doesn't last well.
Title: Re: Sleeve gear bushes replacement
Post by: muskrat on 20.04. 2012 22:25
 Bugga, that's not good.
Upon re-assembly I'd check EVERYTHING. Bent shaft, motor/gbox alignment, sprocket alignment, chain wear(tight spots). Also check the bore of the bush is true to the gear.
Best of luck. Cheers
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 21.04. 2012 01:35
I've done the sleeve bushes but not got the bike running yet and this does not sound promising!

These bushes only have a job to in the lower gears don't they? In top the gear and shaft rotate together?

Astonishing they wore so quickly if so. It probably might mean no oil got the bush but how can that happen.
Title: Re: Sleeve gear bushes replacement
Post by: Brian on 21.04. 2012 01:53
Those bushes usually do many thousands of miles before needing attention so there is something very wrong here.

Even if the material they are made of was incorrect they still shouldnt wear that quick. If you have the three radial holes in the bushes then they will get enough lubrication. What oil are you using ? Do not put grease in the box, thats the best way to kill a gearbox.

The mainshaft, does it have any burrs on it that would act as a cutter ?

Triton Thrasher suggested chain tension and I think this could be the likely culprit. After fitting the primary chain turn the whole show over several times and make sure there are no tight spots in the chain. When you have tensioned the rear chain get someone to sit on the bike and re check it, the rear chain will tighten quite a bit with weight on the bike. Correct tension of both chains is important but its better to be slightly loose rather than too tight. Once you have adjusted both chains make sure the gearbox mounting bolts are tight.

Both the shaft and sleeve gear turn at different speeds, their speeds get closer as you go up in the gears but they dont actually turn together.
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 21.04. 2012 10:34
Ok many questions to answer. Primary chain tension fine I always tend towards a little loose for just this issue. Mainshaft is a smooth as it should be with no obvious bends or kinks. I am using 80/90 gearbox oil and the gearbox bolts were bloody tight it took quite an effort to undo the bolts when I put on the new chains. I shall order some new ones from C&D Autos and redo them again. I will have to book a day off work just to do these but they are being a**es so a day up to my elbows in a BSA isn't all bad *smiley4*. Perhaps the oil just didn't get into the bush due to an air lock or something ???? ???? ???? ????. Its a mystery oh I do approx 130 miles a week so its living a full life *smiley4*
Title: Re: Sleeve gear bushes replacement
Post by: BSA_54A10 on 21.04. 2012 11:45
Which 80/90 gearbox oil ?
Gear & diff oils designed for cars & trucks may have extreme pressure additives that attack copper alloys.
This is why BSA originally specified engine oil in the gear box
Always make sure that any oil that goes in the gear box is marked as "Syncro safe ".
When syncromesh gearboxes became the norm they had to change the additive package as syncro cones were usually bronze.
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 21.04. 2012 13:18
It is motorcycle gear oil the same type I have used for years without any issues. C&D Autos have said they had heard from various customers about issues with the type of metals used wearing very quickly.
Title: Re: Sleeve gear bushes replacement
Post by: wilko on 21.04. 2012 23:26
That bronze eating oil hasn't been around for years. Otherwise every manual gearbox with synchro cones would be stuffed. Another wandering myth!!
Title: Re: Sleeve gear bushes replacement
Post by: BSA_54A10 on 22.04. 2012 11:16
Quote
That bronze eating oil hasn't been around for years. Otherwise every manual gearbox with synchro cones would be stuffed. Another wandering myth!!

No it is still with us as the sulphur compounds are the best for the job.
Truck gear box and diff oils still use sulphur as their extreme pressure anti scuff additive
Some synthetic oils are also not safe for bronze or brass bushes.
Generally the oils you buy from standard auto shops will be "syncro safe" but there are lot of gearbox & diff oils out there.
I just bought a job lot os 22 part drums of manual gearbox & diff oils.
Some are specific to a particular make or even a particular model.
Ie there is an oil for ford & holden V8 diffs and another for Ford XR6 diffs and yet another for standard 6 cylinders.

I am part way through going through the spec sheets but it looks like about 1/3 would not be copper alloy safe.
So yes they are still there.
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 22.04. 2012 12:05
I'm still struggling with brians post that the mainshaft and sleeve gear do not turn together but I thought the top gear ratio is 1:1 and cannot be changed, as on the service sheet on this post below

Also that this makes the BSA gearbox more efficient compared to modern japanese boxes which drive through the layshaft even in top

But even if that's right and all tops are 1:1 all it would mean is that the sleeve gears got worn out in 1st to 3rd.

Puzzled!

http://www.a7a10.net/forum/index.php?topic=296.0
Title: Re: Sleeve gear bushes replacement
Post by: Triton Thrasher on 22.04. 2012 12:39


Both the shaft and sleeve gear turn at different speeds, their speeds get closer as you go up in the gears but they dont actually turn together.

To engage top gear, the mainshaft and the concentric output are locked together, on practically all old British bikes.
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 23.04. 2012 11:59
Im not sure if you have the sleeve gear out yet but if its still a mystery why they need replacing so quickly maybe post a pic up if the worn bushes and mainshaft?

Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 21.06. 2012 09:01
Right I now have the new bushes-I know how long has this taken!!. I will try to fit them this weekend and carry out an investigation on the old ones. C&D supplied the new set, two long bushes this time,actually too long I had to cut the excess sticking out the sleeve gear. Still better than too short. I shall aim for 1 thou clearance. Wish me luck.
Title: Re: Sleeve gear bushes replacement
Post by: Topdad on 21.06. 2012 09:55
The very best of luck, your perseverance should be rewarded , Regards BobH
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 23.06. 2012 15:31
Just pulled the box apart and look what I found...

(http://farm9.staticflickr.com/8145/7425784702_89489f361d_m.jpg)

Looks like the bush shifted a little and blocked the oil ways *sad2*
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 24.06. 2012 22:34
Just finished the rebuild all seems ok will find out tomorrow when I go to work. Again fingers crossed *smiley4*
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 25.06. 2012 07:00
For what its worth looking at the pic I agree it seems to be lack of oil, leading to the bush melting onto the mainshaft? Either that or the shaft was too tight a fit in the bush but I guess you would have checked that....other possibility is the primary chain was too tight as I think was mentioned before. Good luck this time!

Just a thought did you clean off the traces of bush off the shaft?
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 25.06. 2012 08:37
As much as I could  as I didnt want to damage the shaft(I had to have her back on the road today for work). I checked with my next door neighbour who was in engineering-sadly retired so no access to engineering stuff-and he agreed it was nice and smooth and no increase or decrease in shaft diameter. I checked the old sleeve gear and the bushes had slightly moved enough to block the oil way. If I remember right they were easier to press in than these last ones I did. Got to work ok most of the horrible vibration had gone just left with the standard shakes now ;)
Title: Re: Sleeve gear bushes replacement
Post by: duTch on 25.06. 2012 09:15
Good luck with it 500!
 Now if you'll excuse me regressing a bit to:-
Quote
(from KiwiGF)I'm still struggling with brians post that the mainshaft and sleeve gear do not turn together but
  Did you work that out Kiwi, as while I was figuring out my speedo drive a while back,(someone tell me if I'm wrong-quite likely) I noticed that if the sliding gear that engages with top(sleeve) gear is engaged at the same time that its mate on the layshaft, it'll lock up? It seems to me that the action is from clutch to mainshaft(obvious) to mainshaft-sliding-gear(disengaged from sleeve gear),to it's mate on layshaft engaged with layshaft fixed gear, to sleeve gear& sprocket-->   hence the mainshaft and sleeve gear don't spin at the same speed?? As I said I could be wrong, but I wanna know too??
  cheers duTch
Title: Re: Sleeve gear bushes replacement
Post by: muskrat on 25.06. 2012 10:22
 I take it you didn't get much sleep last night  *smile*. You'll get a job on a race team, building boxes that quick  ;).
Best of luck.
Cheers
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 25.06. 2012 10:40
Two hours to rebuild box/clutch etc. I reamed the bushes the day before. I was indoors early enough for the England team to dissappoint me  *conf*
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 25.06. 2012 12:41
Hi Dutch, with the benefit of having all the gears on the bench.....in top the drive goes
1. clutch to mainshaft 1:1
2. Mainshaft to sliding gear nearest the primary drive as that gear is on the m/s spline so always rotates at m/s speed. 1:1
3. That Same sliding gear above (via dogs) to the sleeve gear as the selectors engaged those 2 gears in top 1:1
4. Sleeve gear to final drive sprocket 1:1

So the sleeve gear and m/s rotate together in top. 1:1

This pic has the shaft and gears side by side. Is Fosters counted as a beer in Oz then :-)

http://www.a7a10.net/forum/index.php?action=dlattach;topic=5742.0;attach=12802;image
Title: Re: Sleeve gear bushes replacement
Post by: duTch on 25.06. 2012 19:21
Hi Kiwi,
         I've strange sleep pattern from working random nights(like last week), so tried to work gears out 2-4am, but Might be best to let the other guys explain their point of view, too much for me at the mo', the way the gears engage?
  Would be easier to see in the inspection cover of a S/A box, which I don't have.
 Dunno 'bout the fosters- staying away from that just now!!

Cheers duTch
Title: Re: Sleeve gear bushes replacement
Post by: jjbsa on 16.07. 2012 17:58
Sorry not to have put in a pennyworth earlier - I had not had a look at this thread.
The rapid bush wear is almost certainly due to using oil with sulphur-based extreme pressure additives.  I once did this and only caught the problem because I happened to look into the gearbox for another reason after 300 miles.  By then the bush was completely dry, with dark brown dusty material in it, probably cupric sulphide.  The shaft was OK.  ALthough most modern gearbox oils no longer have sulphur EP additives it is best to make sure the oil in these boxes is either engine oil or one that the maker says is OK for bronze bushes.  The very good Opie oils website
http://www.opieoils.co.uk/ sells most oils and has data sheets on quite a few of its oils.  It's possible to identify oils that are definitely OK by these means.
Re Reaming, best to set the gear up on a bridgeport and run a good 13/16" reamer gently though the new bush, with lubrication.  This will give the right clearance for the shaft.  There should be a gap between the 2 plain bushes.  I always got old ones out with a hacksaw blade and I found the bore was not hardened as mush as the hacksaw blade!
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 16.07. 2012 21:53
The high wear rate was down purely to the fact the bush had moved and blocked the oil holes. Hence the rapid new to knackered in under a month wear rate. As for the reaming my particular mainshaft had worn so the 13/16" reamer would give a sloppy fit. It has been running really well with no wandering clutch. The clutch still needs replacement its well notched innit *smile*
Title: Re: Sleeve gear bushes replacement
Post by: duTch on 17.07. 2012 09:43
Must apologize, but just realized that my query with Kiwi, about ratios is more pertinent to the other thread that was running concurrently, re your mainshaft, and if you wish to respond, best do it there.
  I don't want to flog a dead horse but understand the main/layshaft bit, but my confusion is the fact that the ratios stated in specs give 'gearbox ratios' ranging from 1:11~ to 1:4.2~. is this overall ratios including crank-clutch/front/rear sproket?? or how is this otherwise calculated?
Cheers duTch
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 17.07. 2012 12:03
Hi Dutch,  in top the gearbox is definitely 1:1 ratio.

The bottom gearbox ratio is calculated by multiplying the ratio of the 2 bottom gears (the layshaft/mainshaft pair nearest the kickstart) and the 2 constant mesh gears (the pair nearest the primary drive).

I've still got the advantage of having my gearbox apart whilst I wait for new layshaft bearings from Draganfly :-(

I've been able to study the   *problem* thing for weeks now.







Title: Re: Sleeve gear bushes replacement
Post by: duTch on 17.07. 2012 12:24
Yeahbut,yehbut, I hear what you're saying there,and don't dissagree, but what I'm referring to is what is on page 57 of my 1973 Haynes book, same as I've seen in other factory pages??  -Example->

A10- top    4.42
     third     5.36
  second     7.77
  bottom   11.41
??
 
PS can't you just get bearings from a bearing supplier??
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 17.07. 2012 12:43
Hi Dutch those are overall ratios made up of reductions in the gearbox, primary and final drive as per yr post above.

I doubt I could get the kickstart side plain bush layshaft bearing locally, I could get a one off made locally but decided to buy one instead along with other parts I need but thought I didn't.
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 25.09. 2012 16:17
Well here we are again noticed the vibration again. When replacing the clutch(that really needed doing and is now a clutch to be proud of) the shaft shows signs of wear,and vibrates. Until I strip down again I have a theory. The reason BSA drilled quite large holes in the bushes was to hold more oil?. Bear with me on this. When supplied with new bushes you need to drill oil holes yes?. So we don't have to line up the oils when pressing in we do them after resulting in quite tiny holes. This, I guess, would not present a issue in a pressure fed oil system, but in a box with the gears flying around and an oil bath relying on luck to fed oil by splash into spinning shafts and gears through tiny holes is asking alot. Ah I hear you ask "I have tiny holes(fnarr)and my shafts do not move". Well I am doing at least 150 miles a week so the issue may show up earlier and I suspect parking on the main stand since the side stand broke does not help oil flow into the holes. So if you have large holes like BSA designed them perhaps thats why?. Or am I talking out of my bum? *smile*
Title: Re: Sleeve gear bushes replacement
Post by: bsa-bill on 25.09. 2012 16:32
On the occasions I have replaced bushes (they came with holes in them) I line them up, press them in then check the oilway by trying a rod or spindle down through the case into the bush, said rod or spindle being as close to a tight fit as my shed content will allow, if I'm not happy I use a drill with a speed adjustment to slowly and carefully drill through the bush if it's not aligned correctly,  then you have to clean up the inside of the bush to remove any burr.

A hand drill would be the obvious choice for this job but that is one tool I have always wanted but never remember to buy when out and about - a hand drill and a memory and my life would be complete (not sure I like the sound of that)
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 25.09. 2012 19:54
I used a dremel drill nice and small and fast *smiley4*.
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 26.09. 2012 07:29
I drilled the holes in the bushes first the same size as was there already, they are quite a lot larger than the casing holes so you can get them misaligned a bit and not block flow.
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 18.01. 2013 10:41
I know this is an old post but I fitted Draganfly sleeve gear bushes and they were toast after 600 miles. For some reason they seem to have glued themselves to the mainshaft and melted and turned inside the sleeve gear, lots of brass filings in the box etc

I'm just wondering what to do next! I've ordered more bushes from Draganfly today and all I can think of is to Ream them to a bigger clearance this next time, and use bearing retainer to ensure they do not turn inside the sleeve gear.

Any thoughts? Is it possible these thin bushes are not strong enough to get a permanant interference fit ?

Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 18.01. 2013 10:45
I gad that same issue with them turning and blocking the oil holes. I thought at the time they pressed in with ease and the replacemnet ones required more pressure to press in. Like you I thought I had made them too tight,now I'm not so sure *conf*
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 18.01. 2013 10:50
Hi bsa500 so the bushes that were a tighter fit..were they solid brass or steel backed and have they lasted this time for you?
Title: Re: Sleeve gear bushes replacement
Post by: BSA500 on 18.01. 2013 13:05
Solid brass and so far they seem to holding up ok. I still have vibration I am leaning towards other gearbox issues either bent mainshaft or bearing replacement. I got a dial gauge for crimble so when I am next playing with the clutch I will check the shaft for run out.
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 18.01. 2013 18:11
THanks 500, I'm away for a while now and will get onto the job of replacing them once I get the new bushes from draganfly.

I wonder if BSA "glued" these bushes into the sleeve gear? I'm going to this time anyway!
Title: Re: Sleeve gear bushes replacement
Post by: chaterlea25 on 18.01. 2013 23:23
Hi Kiwi, BSA500 and All,
"Brass" is not a term to use when talking about gearbox bushes, brass wouldnt last kissing time!!!
The original bushes were/are steel backed with a bronze lining
This would make the bush "stable" in size after pressing in and not contract like a solid bronze bush will do after installation,
Fairly recently I had trouble with a solid bronze bush which tightened after a mile or two, even though it all turned nicely on assembly *problem*
Since then I have sourced a set of NOS steel backed bushes, waiting until I get time to install them

Reasons why bushes fail after short milages must have to do with , material incorrect, chain tension incorrect or
incorrect fitment/ bent shafts etc
I really dont believe the oil holes have much to do with it, !!!!! other makes and models survive away without any

HTH
John
Title: Re: Sleeve gear bushes replacement
Post by: BSA_54A10 on 20.01. 2013 11:39
THanks 500, I'm away for a while now and will get onto the job of replacing them once I get the new bushes from draganfly.

I wonder if BSA "glued" these bushes into the sleeve gear? I'm going to this time anyway!

No the bush is shrunk fitted to the steel backing then reamed out to size.


The material to use is 85:5:5:5 leaded gunmetal.
I would have no worries fitting a plain gunmetal bush with .002" to .004" interfearence fit
Title: Re: Sleeve gear bushes replacement
Post by: KiwiGF on 22.01. 2013 09:19
hi chaterlea, do you know where i can get steel backed sleeve gear bushes?

ref other post i meant maybe bsa "glued" and  also have an interfence fit....sorry i should made this clear... as to me the bushes do seem very thin, to maintain the pressure over time, and also I had a strange experience which got me doubting my sanity when I was fitting the bushes that just failed...i fitted them into the sleeve gear and the mainshaft fitted  just right with no reaming required  - which was as i expected given they had  a few tho clearance before pressing into the sleeve gear and the sleeve gear did not compress them THAT much.......but a couple of days later they had  "shrunk " and required reaming for the mainshaft to fit through them...i suppose with hindsight i should have realised something was amiss.

Im wondering if i will find the same happens with the new solid bronze bushes when they arrive from draganfly, but I'll only fit the non steel backed bushes a second time if i cannot find any steel backed bushes instead.
Title: Re: Sleeve gear bushes replacement
Post by: chaterlea25 on 22.01. 2013 11:18
Hi Kiwi
PM sent

John