ATC 125M grinding click while driving, might have got burnt on deal.

[Bushman231]

I am not new to 3 Wheelers and have been very lucky and have had no major malfunctions with any machines. Last week I bought a 1984 125M that looks good, runs and had no obvious red flags as to it might have issues. When I bought it the owner said the chain was loose and I knew that was easy to adjust and would cover that when Giving it the once over.

After taking the slack out of the chain and oiling the dry K & N air filter, I took the bike for a spin. To my disgust the grinding click that emanated from the left side seemingly from where the front chain sprockets located was still there and seemed to be worst in 2nd gear.

I adjusted the clutch and no affect. Pulled off the right side case cover and no loose bolts or anything. Put the hi low sub trans in neutral and noise still there then notice the case on the sub tranny had silicone on it. Pulled the sub trans off and could see it had been broken and the case was welded and a gear was broken but repaired as well. Started the bike with sub trans off and noise was still present.

Now it seems either there is gear damage or maybe the bearings on the chain sprocket shaft. Splitting the cases is not a happy place for me, I found another 125M that looks like the engine might be worth transplanting or just the tranny.

Anyone have a click-grindy noise come from the front chain sprocket area that was most noticeable in 2nd gear that was NOT gear related? After seeing the sub trans housing grenaded I hope the carnage did not make it inside the crankcase.

I gave $300.00 for this bike and it has nice tires, seat, plastics OK and clean gas tank as well as runs well. It's a bike for my kids and am bummed it seems to be a gear issue.

[Bushman231]

Some pics of bike

[knappyfeet]

Looks like a nice machine. Aside from the noise.......how does it run overall in all the gears and at all speeds?

[Bushman231]

The bike shifted through all gears and worked as expected. I say it was about the same as our 1985 110. Other than noise it's a good bike.

[barnett468]

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if the noise is only in second gear, it is most likely second gear inside the trans because the clutch shaft spins whenever the engine is running and the countershaft only spins when the bike is moving.

it might be helpful if you could post a video of the sound.

[Jmoozy27]

Did you inspect the teeth on the sprockets primarily the countershaft (front) sprocket? To me it sounds like it's either slipping or it has something stuck behind the sprocket.

[knappyfeet]

Did you inspect the teeth on the sprockets primarily the countershaft (front) sprocket? To me it sounds like it's either slipping or it has something stuck behind the sprocket.

Yea this might be an issue also but if it ran and accelerated fine then you need to split the case and get into it before it gets worse.

[Bushman231]

I did pull the clutch cover and alls well. The Posi-Trans is a different story, the case was broken and the gear inside was damaged. Some pictures to show the situation.

[barnett468]

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i cant see exactly what is damaged but the obvious plan would be to fix it and then see if the noise is gone.

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[350for350]

If you can get the other 125 for a reasonable price, I say do it. That way you still have it for a back up if all else fails. You have a nice trike by the way. I'd keep it around and don't give up on it!

[Bushman231]

Going to pick up the donor ATC 125M and hopefully there's enough stuff to get this bike right. Slowly building up my courage to split the case if need be. Bought a full gasket set so might as,well go for it.