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  #1  
Old 11-12-2013, 12:43 AM
kittletstv kittletstv is offline
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Default SUNL GY6 150 Loss of Forward / Reverse drive

My daughter was driving our buggy this weekend when it lost both forward & reverse drive action. The engine runs fine and when you accellerate it appears to want to move but won't roll under it's own power. For a while now it seemed to have a speratic jerk almost as if it was jumping a tooth on the sprocket/s but that did not appear to be the cause. I checked the gear oil just before she took it out and it was full. I have not pulled the externally mounted forward / reverse gear box off yet but I suspect that there is a problem internally with the unit itself. Anyone have ideas / suggestions for this problem? Thanks for your help.
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Old 11-12-2013, 06:53 AM
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zman007007 zman007007 is offline
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sounds like a broken or stripped gear or shaft.
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Old 11-12-2013, 09:54 AM
kittletstv kittletstv is offline
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Hi zman, thanks for responding. That's what I was affraid of maybe being the case. Do you know if / where repair parts are avaliable for the gear box, or is it better to just replace it?

Last edited by kittletstv; 11-12-2013 at 09:57 AM.
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Old 11-12-2013, 10:10 AM
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if this part was made by sunl also you may be able to get parts from them or who ever they would recommend. some pics of it would help us alot
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Old 11-12-2013, 10:20 AM
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i'd take a look a the cvt and check the belt, clutch and variator rollers. the external reverse assemblies are pretty robust. the only "typical" issues with them is cable adjustment. this sound more like a cvt problem.
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Old 11-12-2013, 11:02 AM
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Quote:
Originally Posted by x-bird View Post
i'd take a look a the cvt and check the belt, clutch and variator rollers. the external reverse assemblies are pretty robust. the only "typical" issues with them is cable adjustment. this sound more like a cvt problem.
Ditto!!!!!
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Old 11-12-2013, 11:08 PM
kittletstv kittletstv is offline
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I disassembled the entire CVT assembly previously, checked & cleaned everything, and replaced the rollers & belt as a routine maintenance item. I can see the output shaft from the CVT drive on the outside (right side) of the engine case to the reverse assembly spinning, however the drive gear that's attached to the reverse assembly is stationary.

Last edited by kittletstv; 11-13-2013 at 12:23 AM.
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Old 11-12-2013, 11:22 PM
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You probably have a broken or striped out gear on the output shaft.
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Old 11-12-2013, 11:35 PM
kittletstv kittletstv is offline
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Are they replaceable?
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Old 11-13-2013, 02:05 AM
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Sunl has been out of business and had some weird setups no one else used. I would first tear it down and find your problem. Once we know the culprit we'll know what we need and hopefully it will cross with one of the common buggies.
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Old 03-05-2014, 01:19 AM
kittletstv kittletstv is offline
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Update on my loss of all forward & reverse drive on my SunL 150. It turns out that all of the mounting screws for the drive sprocket must have backed out, 3 were completely missing and the other 3 had sheared off. I guess I finally found out what that previous sporadic / momentary lurching was while driving the buggy that felt like it was jumping a tooth on the sprockets. Thankfully everything looked good inside the external gearbox. However now I see that the output shaft to the gearbox is bent a little so that's the next issue.
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Old 03-05-2014, 06:42 AM
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Glad to hear it was a simple fix. I only seen that happened one time on my son's buggy. But there was no warning on his, it acted like the belt broke. We had 4 bolts missing and 2 sheared. There were no signs of anything hitting which if they backed out there is not much clearance for them to back out without hitting the case. We figured the factory missed 4 bolts.
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Old 03-05-2014, 09:21 AM
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Thats the first time I've ever heard of that happening!
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