February 13, 200917 yr I need to remove the primary drive on my 1980 349 and found this thread, any other tips as it's sure on there tight! http://www.trialscentral.com/forums/index....y+drive+montesa seems freezer spray on the crank and heat on the gear is the way to go? Thanks Steve
February 13, 200917 yr The only other thing I thought of after looking at the photos again was to make sure your puller contacts the back of the gear evenly so you don't damage the ends of the teeth.
February 14, 200917 yr Author The only other thing I thought of after looking at the photos again was to make sure your puller contacts the back of the gear evenly so you don't damage the ends of the teeth. Yes, agreed! And when using a finger type puller I always clamp the gripping ends so they cannot open up and damage the item being pulled, and/or you
February 22, 200917 yr Author Ah fun and games. First attempt with moderate heat and the gear refused to budge. Second attempt today with a LOT more heat, plus freezer spray and the goddam thing still refuses to move! Frustrating to say the least - I have everything else off ready to split the cases. I have paused for now, not really sure what to do, but got a couple of engineering friends to seek opinions from. I have been using a 3-legged puller, with legs strapped together so they can't open up, and done the thing up as tight as possible. Heated the gear, cooled the crank, tapped with hammer on the puller, all the things that would normally move a flywheel.... Steve
February 22, 200917 yr Sounds like you're covering the bases..........dunno. I haven't tried mine yet, but I sure hope it comes off easier than yours! I think I read that someone heated the gear hot enought that it was almost glowing? Hummm, wouldn't that take the temper out of the steel? I'll be fabbing up a puller myself, Sounds like it ought to be a big-ass strong puller to do the job. Do you have the means to fab a puller that'll allow more torque and thus pulling power?
February 22, 200917 yr Author Sounds like you're covering the bases..........dunno. I haven't tried mine yet, but I sure hope it comes off easier than yours! I think I read that someone heated the gear hot enought that it was almost glowing? Hummm, wouldn't that take the temper out of the steel? I'll be fabbing up a puller myself, Sounds like it ought to be a big-ass strong puller to do the job. Do you have the means to fab a puller that'll allow more torque and thus pulling power? Yes I wouldn't put too much heat into the gear. I'm using a hot air gun so doubt it would get it glowing! I cannot make a puller myself, but the friend I bought the bike off can! so that is the final option.... Steve
February 22, 200917 yr OK Guys, oldie here..I split my first 348 in '76 to repair a cracked big end roller. AT THE TIME all I used was a 3-legged puller, carefully, evenly and gently applied - but I guess the that was then, this is now.
February 23, 200917 yr Author FINALLY !!!!!!!!!!!!!!!! Yes the gear came off at last, 3rd attempt. Here's my setup: Note chain clamped round the puller to stop the legs opening, and I used some foil from a pie(!) to shield the crank from the hot-air gun to try and stop it heating up as much as the gear. The puller was as tight-as, creaking alarmingly, and then just kept tapping the end with a hammer, loosening again so the legs could clamp up tight again, as even with the chain clamped tight they were moving out a little with the knocks, then tapping some more. And off she pops, after some time! Blimey, that was hard work
February 23, 200917 yr I see you have a special left-handed Cota 349 there with the primary drive and gearshift on the left side. That must be a rare one! Congratulations by the way. Good to see you are getting closer to getting it running right. I can feel for you as I went through similar on my 348.
February 25, 200917 yr Author Congratulations by the way. Good to see you are getting closer to getting it running right. I can feel for you as I went through similar on my 348. Thanks! Yeah it was very frustrating for a while. Next difficult task needs a new thread... Steve
February 26, 200917 yr BANG! Omygodwherethef%$$didthatgo! +1 hehe, yup i was there last month. used a three-legged puller with the legs chained up. In the end went for the get it as tight as you can, then using the longest bar you can, carefully approach and give it 1/4 turn, sweating - usually with eyes shut. retire to safe distance, wait 5 mins and repeat. On the 4th or 5th 'turn' the aforementioned BANG, jebus where the "
March 13, 200917 yr Author I have just picked up a s/h 349 bottom end, which hopefully has better gears than mine. The only problem is............. the flywheel and tapered gear are still attached, which means having to go through this trauma again!!!!!!! I have been advised that the way to get the bleeders off is a hard hit on the end of the puller. Not a tap, but a bl@@dy hard wallop with a big hammer. I did hit mine quite sharply last time to pop it off and I'll stick with the normal hammer and see what happens.... Steve
March 13, 200917 yr Thats a score! Gears ought be be less damaged than your others! Soon you may work out a patent procedure for getting that primary gear off. Wayne....
March 13, 200917 yr No, use a big heavy hammer as its the jolt that gets the gear off . I have just removed the same gear off of my 247, i just used two long tyre leavers , one being pushed by my knee and the other by hand and i walloped the crank end with a thor copper and hide hammer once and it came off Dave
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