Mountain Biking - Shifting problems

OK heres my bike.
Trek 6700 frame
Shifter Deore Mega 9
Rear derailer Shimano LX

I have been riding this bike for about 4 years. Recently I have been haveing major problmes with my chain droping from a low (large) gear to a higher (small) gear. This appears to be starting on the top of the casset and this is almost always occuring when im putting some torque on it. My derailer works perfectly shifting when theres little torque applied. My casset is the original and derailer the original. MY derailer has some play in one of the middle joints from a pin thats worn out its hole a little.

Im looking for some opinions on what the cause is, because this is driving me nuts. Also I dont have the $ to go replaing this and that searching for the problem (poor college student). I think my casset could be worn but wanted some other opinions. If i replace my casset should I replace my chain too?

clean it, lube it
i dont have a workstand, so i just flip my bike over and see if the RD is aligned with the gear that it suppose to be in, if not, i just adjust it.

get a zinn's guide and the art of mountain bike maintainance. something like that I own that book, very useful problem is you must read it through and its quite long haha. Im a lazy reader.

Your shift cable is sticking...clean and lube it and it will stop. well more than likely anyway :)

I just cleaned the entire thing lube the entire thing and adjusted and put on all new cables today and its still doing it.


Again it starts to drop down from the top side of the casset, the derailer stays in the right place, This happens after im in the correct gear, just when i apply torque to it.

Ok drumb question, is there a correct order for the chain to be wraped?....

And if i get a new casset do i need a new chain?

did you check all the links? cuz i have one link in the chain that is about to get ripped apart, so in certain gear it will jump.

pix would be nice

OK I have had a chian break in the past few rides, like the past 6 ride and i patched it wiht another chain but i dont think thats tthe problem. I just went over the entire thing today and am still having problems

www.parktool.com

Try that.

The parktool site didnt help me very much, although it was a great site for information. I mesured 12 of my chain links after reading the other recent thread on that and 12 links were 12-1/16" close to 12-3/32". Also recently after one of my last breaks I had to add in some links from an old chain to put it back togather, and im guessing that didnt help the situation. My new question is if im replacing my chain and casset do I need new front chain rings?

You might not need new chainrings since your chain stretch is not too severe. Get new chain and cassette and see how it works. If you don't get chain skips on the chainrings, you're fine.

If you have play in your rear derailleur, that could seriously mess up your shifting (indexing). If there is excessive play, I would replace that as well...use Park Tool site for instructions on installing and tuning the rear derailleur (travel limits and indexing).

My rear derailleur is shifting perfectly for the first time in a long time but the problems I have been having I believe to be associated with chain strech and worn casset.

What are chain skips on the chainrings? Is it when the teeth dont fit the chain right? Or does it occur when shifting?

If you can get to a Shop they can tell you if your chain is stretched.. It is hard to tell by sight. And if it is to far gone then you will most likely have to replace the Cogs too. A severely warn chain wears out the cogs as well.

get a rohloff chain measurement tool its a simple looking device but works. Easy to use too