I was riding this weekend in some deep soft sand and almost made it to the top of the hill when I started sinking and just before I let out I heard a sound that kinda sounded like the chain slipping on the rear sprocket. so I backed back down the hill and started to inspect, and the rear sprocket is getting worn, but not enough to slip for sure and the chain is adjusted pretty much right on. Any ideas what else could make a noise like this from the back end of my trailblazer 400? could it be the "silent" tranny chain i've heard so many horror stories about? I wouldn't worry too much about it, except if it is the tranny chain and it goes out I would be stranded right? or would it just lose reverse? any ideas on what it could be?

 

If it makes a grinding or chain slipping noise and you can rule out the drive chain and front and rear sprockets,then possibly internal "silent" chain" has excessive slack and slipping. I love the name "silent" chain! Not so silent when its worn. At its worst it just wont drive under any kind of load,will just grind. I've replaced quire a few along with the inner forward gear(sprocket) and even tough its a double row chain and pretty tough,its subject just like any other chain as far as stretching and jumping teeth on internal drive sprockets,especially if used for jumping and heavy loads. Plus I would also check for worn wobbly bearings in rear housing(jack up and check side to side play on drive axle) and swing arm also for worn bushings. OPT

 

is it still doing it after you came down or did it go away? if went away, you sure it wasn't caught in your chain while youi were spinning and it was grinding it out? happend alot w/ my wifes blazer going thru mud and dirt. just a thought.

 

I was thinking about that too... I still run the factory chain gaurd and it very well could have been filling the chain with sand and as it goes onto the rear sprocket it could be grinding on it. It has done it twice before, but in the same situation. There's some pretty nasty sand hills around here . I don't do too much with it in the mud, mainly because it doesn't have the shoes for it. Do you think it could be something like that, or the internal tranny chain starting to slip? is there a way to check the not-so-silent chain without taking the trans apart?

 

Just have someone set on the rear or place bumper against a post and open throttle ,if its the internal chain you will usually know it! Under loads is where they start to slip,the worst ones I've had would grind right away. Hopefully yours could just be the chain guard noise as you think ! OPT

 

ok i'll give it a try this afternoon up against a tree... do I need to have somebody sitting on the back while it's up to the tree also? or just trying to drive around with a heavier load? Is there some sort of upgrade/replacement for these factory chain gaurds? Who makes them or (i don't think i can and/or should) can I run without it?

edit

Just wondering how much weight to put on the back with my 300lbs already on there?

 

ok I tried it up against a tree and didn't hear anything. I guess it could be just the sand in the chain grinding against the sprocket. When you guys do get back to look at this I'm open to suggestions about the chain guard ideas...

 

Make sure the chain guard is loose enough that it can move along with the chain,but not enough to loose the bolt and nut. The bolt going through the guide has a bushing and nut and the mounting tab is slotted for flexing. Regardless of what the manual says about tightening the chain(which even some Polaris techs I talked to said is wrong) keep about 1/2" to 3/4" slack measured at top of chain at middle of swing arm. Thats supposed to be the big deal about concentric drive on the later models,the chassis and suspension doesn't put as much flex on the chain as the pre 1996 models with chain drive. Collapsing the rear end and adjusting to manual specs will leave chain way too loose after you unstrap. I adjusted em with about 1/2"-3/4" play for years and never had a problem. Just my opinion and a couple of engineers. OPT

 

the mounting tab i have has a U shape cut out, not just a straight slot. I don't recall ever seeing any sort of bushing in there either.... I just looked up a diagram and it shows the U shaped slot and a bushing on the bolt. I guess I can try to loosen it some and see if it does it again. I had to adjust it one time right after I got it and if I remember correctly it was a little loose, but I could here it making a grinding/clicking noise against the rear sprocket. So maybe I should just loosen it and deal with the little bit of noise? Maybe this noise is the little quirk that this bike has? Unless the U slot is different than the straight one you're talking about OPT? If not and I don't like hearing my chain that much, is there another option? As far and tensioning the chain, I have my wife sit on it and I get it to between about 1/2" to 1" from top to bottom movement on the top of the chain and it has seemed to work perfectly so far.

 

Yes it is a U slot, SORRY,but it needs the bushing if missing for it to move easier,bushing should be in the guide itself! OPT