lifan 125 gear box

[josh193]

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well your not really reading what im saying, what you have just said above coincides with my last bit of advice.



you have to be turning the gearbox input shaft or front sprocket whist at the same time selecting gears..
these are non syncro gearboxs which means the gears wont full mesh untill the shafts have turned a bit, and if they dont fully mesh then theres only 1 other gear it will select and thats the gear you just came from..

it worked. but now i dont have neutral, or is it normal for when you kick it over the front sprocket is meant to move a little bit?

 

[sean01]

yes it is normal, but if you hold the input shaft and turn the front sprocket you'll notice if its in neutral or not...

 

[josh193]

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yes it is normal, but if you hold the input shaft and turn the front sprocket you'll notice if its in neutral or not...

it worked mate thanksss

 

[Ieathumans]

Sean, great bit of information on these transmissions. Saved me from buying a new gear set. The grinding I was hearing when tranny slipped out of second was not the gears eating themselves after all. (at least I don't think so since I didn't split the cases) I decided to play around with all stuff tranny related that's outside the cases first. I believe I see why slips gear. I cannot however find any googles or forum threads that say this is a possible cause. Specifics continued in next post.

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[Ieathumans]

Lifan 125cc, 1d, 3 up, shift star not in the shape of a star ( and functions proper ). I want to call the part that seems to be failing the shift linkage, but not really sure of proper name. It's on the opposite side of the gear selector that you kick with your toe. It's connected to that as well. I noticed when clicking up from first it catches neutral fine, up to second and half the time the part that pushes and pulls the dogs is falling out of place. when I press firmly on this shift linkage ( towards the gear kicker ) the transmission works flawlessly.

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[Ieathumans]

I'm thinking to bend the shift linkage towards the gear selector near where the dog pusher/puller is located. This would take the place of me pushing on it I think. I'm no mechanic, just have a bad habit of buying cheap shlt breaking it and fixing it over and over again. Looking for some input. Thanks in advance.


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[sean01]

sounds like the shift linkage is actually bent, so try what you have said and see...

 

[playajai]

Hi sean i got a 110cc gearbox slips and i got a donor 125cc same gear pattern same looking motor u think the 125cc gearbox fit the 110cc its, manual as well

 

[Ieathumans]

Hey man, why not figure out why your 110 tranny slips? Probably not same. ( needs to be exact fit ).

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[sean01]

Hi sean i got a 110cc gearbox slips and i got a donor 125cc same gear pattern same looking motor u think the 125cc gearbox fit the 110cc its, manual as well

could be the same..

1st check is the front sprocket shaft size.
2nd geardrum design..

after that its still touch and go...

cheaper/easier to buy a new gearbox designed for your engine..

 

[Ieathumans]

After many tests of cycling through the gears, I've come to find out the " finger " on the inside of the engine cover that holds the shift linkage firmly in place doesn't actually hold it firmly in place. This finger allows the linkage to move out of place about 1 or 2 mm. Just enough to allow slippage. This finger on the engine cover seems to be made out of some kind of " plasti-metal " and has been made shorter from force of a fall or a smash of a tree. I guess I understand why these dink motors are hated on. Oh well, easy fix is to gently bend the shift linkage towards the tranny about 1mm. This forum and the information you all provide is priceless to any want to be mechanic like myself.

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[sean01]

lol, im actually surprised you've spent the time to find the actual problem...

most including myself would of thrown the 125 in the parts bin and purchase another engine...

 

[Ieathumans]

That's a good idea, I'm from America so I don't always do the smart thing. Anyway full day riding crazy trails, fight rocky terrain, driving in water even, and this Chang Chang engine shifts smoother than my freakin Harley. Thanks again for all info in this forum as it helped me to completely understand everything about a constant mash transmission.
( teach a man to fish eat allot versus give me one eat once sort of thing ).


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[sean01]

good stuff bro