Author Topic: Gear box & clutch strip down  (Read 748 times)

Offline a101960

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Gear box & clutch strip down
« on: 28.07. 2017 09:36 »
Soon going to be doing a gear box & clutch strip down (4 spring). Should I renew the rollers as a matter of course while I am at it? Clutch has got to be dismantled to gain access to gear box oil seal that needs replacing, there are no problems with the actual clutch itself that I am aware of. Also any special tools that I might need to do this work?
John

Online JulianS

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Re: Gear box & clutch strip down
« Reply #1 on: 28.07. 2017 11:04 »
It will not hurt to replace the rollers - they are 1/4 inch x 0.236 inch or there about. Some  sellers try to pass of 1/4 x 1/4 as the right ones. However they do generally last for ages.

I would suggest a proper clutch puller to pull it off the taper,, but screw the puller body fully in before tightening the centre bolt. There is not really enough space to get a legged puller behing the hub.

The seals can be difficult to replace they are often just a bit too large in diameter to fit the recess and allow it to seat against the bearing and the edge may need trimming. Sometimes they are also a bit too thick to easily get the circlip properly located in its groove.

Offline a101960

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Re: Gear box & clutch strip down
« Reply #2 on: 28.07. 2017 11:17 »
Thanks for the advice Julian. I have also noticed a clutch locking tool advertised are these useful in aiding the clutch strip?

Online JulianS

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Re: Gear box & clutch strip down
« Reply #3 on: 28.07. 2017 11:49 »
This is the one I use. The bar locks against crankshaft allowing the centre nut to be undone and done up without either relying on engine compression or the gearbox and rear brake. Got it on e baynfrom a UK seller. Or easy to make with an old plain plate if you weld.

The single plate type with dogs on both edges relies on compression and/or the rear brake to lock the gearshaft. Usually works ok as long as your brake holds. You can make one if you have an old plain  plate and bonded plate - drill through in 2 places and bolt together.

Online orabanda

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Re: Gear box & clutch strip down
« Reply #4 on: 28.07. 2017 11:52 »
I pack the rollers with grease, and re-pack every 5,000 kms or there-abouts.

Offline Topdad

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Re: Gear box & clutch strip down
« Reply #5 on: 28.07. 2017 11:54 »
Hi john, I've always managed using the rear brake ,you need 3 hands but easy enough.  My clutch as always,prior to last strip down come off without need of a puller .This last time it was a bugger and all I had was a 3 legged puller so I can confirm that it is fiddly but can be done . My puller came from halfords and I simply ground the end of the legs to fit behind the clutch centre .
Again I got my seal and all other parts from draganfly and the seal /clip fitted without issue after I'd fitted a new bearing which had seated properly by heating the case . Best of luck ,Bob
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Offline chaterlea25

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Re: Gear box & clutch strip down
« Reply #6 on: 28.07. 2017 12:51 »
Hi All,
John,
Somewhere on the forum theres a thread on homemade A10 tools ?/
I made a clutch locking tool from two old plates bolted to a length of flat bar, so it locks the crankshaft as well
You will also probably need the crank nut tool to remove the crank sprocket so as you can remove the inner primary
(depending on sprocket size)
Some of the clutch shaft adaptors have different threads *warn*
Original ? are 26 TPI and some modern replacements are 20tpi,  BUT??? it seems quite a few of the extractors on the market are 24tpi *conf2* *conf2*
Some time ago I posted a guide to the primary side rebuilding, that may help you?
http://www.a7a10.net/forum/index.php?topic=9646.msg70166;topicseen#msg70166

John
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Offline a101960

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Re: Gear box & clutch strip down
« Reply #7 on: 28.07. 2017 13:12 »
John thats really great. My engine sprocket is fitted with the SRM fastner. Hopefully my puller is the correct thread size, it does say 26 TPI on the packageing. It also warns about making sure that it is screwed in properly and that once tight, from then on to turn only a quarter of a turn at a time and to tap with a metal hammer between each turn. I am not looking forward to doing this, but needs must, as the leak will only get worse it certainly won't cure itself! I have also ordered a clutch looking tool, and I will get my mate to weld on a bar as Julian described. How long does the bar need to be by the way?
John

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Re: Gear box & clutch strip down
« Reply #8 on: 28.07. 2017 16:15 »
30 cm on mine.

Online JulianS

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Re: Gear box & clutch strip down
« Reply #9 on: 28.07. 2017 16:53 »
My A10 4 spring puller is 1 inch 26 tpi. Had it for over 40 years and works fine.

The service sheet 711 shows it as 1 inch x24 tpi.

A65 from 1966 had  x 20 tpi as did some Triumphs.

Offline bikerbob

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Re: Gear box & clutch strip down
« Reply #10 on: 28.07. 2017 19:08 »
As Julian says if you do decide to replace the rollers make sure they are the correct length I ordered a set and they were to long you are are only talking of a few thou you cannot see the difference just by looking you have to measure them if they are to long when you tighten the center nut your clutch will lock up.

Offline duTch

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Re: Gear box & clutch strip down
« Reply #11 on: 28.07. 2017 20:19 »
 Forgot to hit 'send' a couple of hours ago

 In addition to what Julian says, I think the rollers ate often listed as 1/4" x 6mm, or I think more correctly 1/4" x 15/64"....can't add anything on the clutch,  but depending on the sprocket nut you have, the usual one is round with 2 or 4(?) peg slots...which may make an easy Friday arvo/ Saturday morning task into a weekend bender .... *beer*
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Offline bikerboy

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Re: Gear box & clutch strip down
« Reply #12 on: 30.07. 2017 01:51 »
I follow a policy of "if it ain't broke dont fix it" so if there is nothing wrong with the rollers why replace them?

As for locking the clutch I have rivetted two old clutch plates together to lock the chainwheel and reply on holding the rear brake on or pushing a heavy cloth in the chain which eventually locks it up

Offline Tomcat

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Re: Gear box & clutch strip down
« Reply #13 on: 30.07. 2017 08:26 »
It'd be a good idea to fit one of these SRM nuts while you're in there. Kill 2 birds with one stone.  *smile*  http://shop.srmclassicbikes.com/product/gearbox-sprocket-nut-oil-seal-bsa-pre-unit-swingarm-models
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Offline BSA_54A10

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Re: Gear box & clutch strip down
« Reply #14 on: 30.07. 2017 10:57 »
John thats really great. My engine sprocket is fitted with the SRM fastner. Hopefully my puller is the correct thread size, it does say 26 TPI on the packageing. It also warns about making sure that it is screwed in properly and that once tight, from then on to turn only a quarter of a turn at a time and to tap with a metal hammer between each turn. I am not looking forward to doing this, but needs must, as the leak will only get worse it certainly won't cure itself! I have also ordered a clutch looking tool, and I will get my mate to weld on a bar as Julian described. How long does the bar need to be by the way?
John

Use an impact wrench to tighten the center bolt.
The ratchet action usually pops them off very easily, much better than the tap & turn method.
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