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Fitting Those Pesky Trials Gears
Posted: Tue Mar 29, 2016 8:22 pm
by WJS
Hi there I am "attempting" to fit a set of our hosts 14t trials pinions to my Indian Albion 4 speed box. What a truly horrendoue job this is!! I have stripped everything down and got both Main shaft and Layshaft completely out of the bike. Guess what? Both of the original small pinions are stuck fast on the shafts. Really stuck. I have tried heating them as hot as my butane torch can get them and still they are seized on tight. I dont want to risk damaging the shafts by walloping them.
Has anyone else been in this predicament and figured out a clever removal technique please? I don't want to have to rebuild it all without doing the job I went in there to do. Any suggestions? Its driving me crazy.
Thanks
Fitting Those Pesky Trials Gears
Posted: Tue Mar 29, 2016 9:52 pm
by Mark M
They are tight, I rest the pinion on the open jaws of a vice and hit the shaft using a suitable drift. It's not ideal workshop practice but it works. They were probably pressed on originally so you need to improvise if you haven't got a press to take them off!
REgards, Mark
Fitting Those Pesky Trials Gears
Posted: Tue Mar 29, 2016 10:46 pm
by Cleggy
A three or two legged puller works OK too. Gentler than a drift. TTFN Jack
Fitting Those Pesky Trials Gears
Posted: Tue Mar 29, 2016 10:48 pm
by mauri
heat and a puller, be it mechanical or hydraulic will do the trick.
avoid hitting two pieces of harden steel together, if you want tho use brute force use a piece of copper or bronze between the axel and the hammer.
otherwise it can sheer of with nasty surprises.
use safety gear as well, glasses, gloves.
it only takes a second to lose an eye with something minor like this, i have been a first person witness to this type of injury.
Fitting Those Pesky Trials Gears
Posted: Wed Mar 30, 2016 5:46 am
by Leon Novello
Another option is to wrap a bag of ice or dry ice if obtainable, around the shaft to contract it, then heat the gear to expand it. Similar to fitting valve guides, where the head is heated in the oven whilst the guides are shrunk in the freezer.
Fitting Those Pesky Trials Gears
Posted: Wed Mar 30, 2016 6:54 am
by Ian Martin
This is not a normal maintainence job we would do looking after our bikes with the usual enthusiasts tools, equipment and knowledge.. It's an engineering problem that requires an engineering solution. Take the shafts and new gears to a local engineering jobbing workshop who will either have a press or know someone with one. They will do this for you safely, quickly and at a cost that will be small compared to the amount you are already prepared to spend on the project you are tackling. If you do decide "to have a go" then take note of all the safety advice given above, let us know how you get on. Ian
Fitting Those Pesky Trials Gears
Posted: Wed Mar 30, 2016 7:46 am
by Dennis C
They are as said pressed on and can be very tight, so tight that a normal puller will not move them, Mark's method is a good way to do the job but I always use a brass drift then no damage will be caused to the shaft.
Fitting Those Pesky Trials Gears
Posted: Wed Mar 30, 2016 10:50 am
by Mark M
A 3 leg puller will usually do it as Cleggy says (I had a picture illustrating exactly this process in my Ebay Bullet article in the Royal Enfield Magazine) but sometimes more severe treatment is needed. Note I said use "a suitable drift", brass is good but not everyone will have such a thing. A piece of mild steel is ok for this.
REgards, Mark
Fitting Those Pesky Trials Gears
Posted: Wed Mar 30, 2016 12:37 pm
by PeteF
I'd be taking this to someone with a press. Hitting it with a large hammer is not good practice (with or without a drift) Even if you do get them off, you still need to get the new ones on and a decent press (with someone who knows how to use it properly) will have the job done in a few minutes.
Fitting Those Pesky Trials Gears
Posted: Wed Mar 30, 2016 8:04 pm
by Dennis C
Sorry my last post should have read, sometimes so tight a normal puller will not remove them.
Pete, yes that is the ideal way to do the job and once many years ago I had to get help with a press but most times one of the selection of extractors I have will serve but if not plan B will almost always do it, it's not about a big hammer it's more the sharp shock that moves them and to date I have not done any damage with a brass drift.