If the chain and rear sprocket are that far gone I would want to take a look at the front sprocket. If you use a mirror and a strong light you can at least see some of the teeth. I would prefer to pull the covers and have a good look. The Hi/Low box really isn't that complicated. Main thing to do is pull the lower shaft out with the shift fork on it. There is a spring and ball bearing on it that likes to pop out if  separated.     

  Neal     at the   theCTshop.com   in  Auburn Ca.


                                                       If it works, Don't fix it