main gear wont come off

Jason Luther /

i cannot break the main gear loose on my wards riverside, i got the clutch and everything else off, but i cant get the nut to budge. is it possibly reverse threaded? i cant tell because the nut is flush with the end of the bolt. any ideas? -jason

Re: main gear wont come off

Jason Luther /

upon looking at other repair manuals on-line. it appears as thoug the 'main gear' (large gear that meshes with the clutch gear) i am talking about is inside the crankcase on most engines. as luck would have it, not on mine. so i cannot budge it, and therefor cannot open crankcase. one again, thank you e-bay ;) -jason

Re: main gear wont come off

did you get the nut off that holds the main gear to the countershaft?

Re: main gear wont come off

Here's what i'd do if i didnt know which way the threads are.

First i'd use a really tight 6 point socket.. no adjustable wrench or pipe wrench or whatever. And, clamp the engine down really well so it cannot move at all. Bolt it to a piece of lumber or something and drive the car onto it to hold it down if you have to. Or bolt it into the frame and drive the car onto that :)

If the shaft has to be prevented from turning, don't do a half-assed job by sticking a screwdriver through a hole in the gear or anything like that. Make it good and secure without danger of bending something or the fastener(s) slipping.

Once everything is nailed down tight, turn the nut both ways with a torque wrench.

Start off at like 30 lbs one way and 30 lbs the other. Keep increasing it by about 10 or 20 lbs, and turn both ways. This way there's no real danger of over-torquing it or breaking something since it's gonna come off as soon as you reach the right torque in the right direction..

Re: main gear wont come off

Jason Luther /

my biggest problem is preventing the gear form turning. the drive sprocket also turns, so i put the chain on and wedged it down tight, and i tried like hell, in both directions, to break the nut free, no go. im afraid of breaking something if i wrench on it too hard, but thats the only way i could keep the gear from turning. thanks-jason

Re: main gear wont come off

soak it with some penetrating oil, then try again, I believe that it will be lefty loosey, but the bike may be all weird and be righty loosey, but most are regular right hand(tighten) thread

Re: main gear wont come off

that chain thing works ok.. better than jamming sticks of wood in the gears :)

I have a long torque wrench that provides a lot of leverage. So, instead of sweating with a short wrench and sore fingers, i can pull steadily with a lot of control and get a good feel .. (hmm.. Ronald Reagan, rest in peace)

..get a good feel for whats happening.

Stop and take a real good look at that thing. If there's nothing but a nut and a threaded shaft, it will come off when it's turned hard enough.

Re: main gear wont come off

Yes, I have to reiterate the screwdriver-through-the-gearhole thing...I broke gears on my Sport MKII doing that.

Re: main gear wont come off

Jason Luther /

okay 'operation riverside revival' is back under full steam!! i dug out my vise and nailed it (yes 16 p framing nails, didnt have lags) to the work bench, and presto! i see why they call it 'cracking' the case. by the way, wood in the gears didnt work ;). so the beast is in a million pieces in my garage. now for the bad part..... the magneto side crank bearing is shot. the crankcase has a hairline crack, and it looks like it was glued or something at the factory. ( i say at the factory because it was quite apparent this thing was never opened before) so when i replace the bearing can i do the same thing, but with epoxy or something?. next.... the needle bearings in the small end of the connecting arm are missing, broken, halfway hanging out etc., how in blue blazes do you get them in there? it looks like the flywheel halves where pressed together. thanks again to everyone who has been holdin my hand (figuratively of course) throughout my ordeal-jason

Re: main gear wont come off

If you mean the smaller end of the connecting rod needle bearings, they are usually caged. A thin metal cage holds the needles and is a single assembly.

But how could they be messed up if you just replaced the piston? You surely would have noticed that the bearing was shot when you installed the piston pin.

Cranks are pressed together. It takes real equipment to disassemble and reassemble them properly. And since you mentioned the crankshaft, if you were speaking about the big-end of the crank bearings being messed up, fixing that is a job for professionals and is bad news. If that big end bearing is gone, that journal is also shot and would need to be welded up and turned down to the proper size. I actually know very little about this but a few phone calls will tell the story.

Epoxy should work.. JB Weld or similar.. I assume the crack is somewhere near that bearing. The only concern is to be careful about epoxy blocking any lubrication point. The bearing boss may have a little hole through which a mist of fuel/oil can pass.. Anyway, i wouldn't slop epoxy all over the place.

One other thing i forgot to mention that may apply. Some seals are directional. They need to be installed so that the rotation of the shaft follows the little arrow on the seal.

keep on truckin'

Re: main gear wont come off

Jason Luther /

more 'good' news i see. yes it is the big end bearing that is shot (there isnt a bearing on the small end). so i guess i need to look for a whole new crank shaft/flywheel then huh? thanks again for the insight.-jason

Re: main gear wont come off

Maybe whoever rebored the cylinder can do a quick evaluation of the crank and the connecting rod big end. Be nice to know what the options and their costs are. If they can't actually fix it they will know who can. One bright spot is you saved the majority of labor cost by removing the crankshaft yourself.

As far as finding another crankshaft.. damn.. cant even find a manual. Maybe Monkey Wards still has some connection to Benelli or has archives in the vault. They could both be out of business afaik..

My Kreidler lost it's con-rod big end and that was the end of that bike. If i knew then what i know now i woulda put some effort into getting it fixed, or at least pricing the job before hauling the bike away. The crankshaft sat on a bench for a month 'till i got tired of looking at it. I'm still sorry about dumping that bike.. it was years before i had another moped...

Re: main gear wont come off

Jason Luther /

cosmo motors has a bunch of parts for the ole girl, i just shutter to think what it will cost. they have a manual, but it was like $30, i think i can wing it :). when you say the shop may be able to evaluate it, are crankshafts actually fixable?-jason

Re: main gear wont come off

Cranks are often fixed. Journals can be welded up and ground down. They may be able to do it without disassembling the crank. Plus there are all sorts of modifications and straightenings and balancings they regularly do to them.

The question is what is the extent of the damage and the cost. Then you can decide of repairing it is cost effective. I'm gonna guess that you also have to fix the connecting rod's big end bore. If damage is mild maybe a honing and a new, oversized bearing will do it. I really am clueless about it.

Re: main gear wont come off

Jason Luther /

okay thanks, ill check it out. cha-ching!-jason

Re: main gear wont come off

heh.. it's only money.

btw, when i said they might not have to disassemble the crank, I was thinking auto-cranks. The connecting rod big end on those are split and can be removed by removing bolts.

On yours they will have to disassemble the crank to get the con rod off.

Re: main gear wont come off

Jason Luther /

and it looks like theyll need a 3 ton press to get the crank apart. if i know i can buy a new crank, ill take a house jack and make my own press to try and seperate it. ill go between two trees or something.-jason

Re: main gear wont come off

sure looks easy, don't it? :)

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