I have a 99 sc500 and when I was riding it would make a popping sound around the front sproket and then the chain will be really tight or really loose, depending on the direction I am going. I have noticed that the rear axle has up and down movement and the swingarm does to. I knw the bearings got to be replaced, could loose bearings keep the chain from staying at the right tension, or is it a transmision issue? any thoughts or simular experiences would help. thanks

 

You will continue to have chain adjustment problems until you replace any worn bushings/bearings that you have. Worn bushings and/or bearings allow the axle to get closer and farther away from the front sprocket, thus tightening/loosening the chain......depending on direction and traction of the back tires. Like I said, replace any worn parts before addressing chain adjustment.

Personally, I had bronze swingarm bushings made instead of going back with Polaris plastic bushings. I keep my machine lubed religiously, and the plastic bushings still wore out. I have had no problems with the axle bearings yet. Since installing bronze bushings in the swingarm, everything stays really tight, and chain adjustment is hardly ever. Hope this helps,

Waylan

 

This weekend I was lubing a friend's Trail Boss (actually 2 of them).

Can someone tell me how the chain tightening is done? Believe it or not, it isn't obvious to me. I like to never figured out how to get the external tranny oil out.

Thanks in advance.
Chunky

 

Chunky,

In order to tighten the chain, loosen the 2 pinch bolts on the axle carrier, and if there is a brake caliper mounted on the rear axle, loosen the one of the 2 bolts holding it onto the axle carrier. Look at the rear sprocket, and there is a hole that goes through the sprocket and into the axle carrier. By putting a screw driver through the sprocket and into the axle carrier (make sure you use one that fits snug), you can then push the bike forwards or backwards, and it will rotate the axle carrier. The axle carrier is built oblong, so that rotating it one direction will place the axle farther from the quad, and rotating it in the other direction will bring the axle closer. Once you have got the desired chain tension, retighten the brake caliper mounting bolt, along with the axle carrier pinch bolts. If you have any other questions, let me know.

Waylan

 

Thanks, you da man.

I will run home and try it.


Chunky

 

make sure to torgue the bolts to 50 ft pounds or else it will haunt you

 

I have the bearings and bushing on order, did you have to remove the rear transmision to change the swingarm bushings? I think the reason my bearings went out is the wheel spacers and realators(tires) I have on it. Thanks for the info, and good idea on the bushings, I don't understand why polaris would use plastic instead of bearings.

 

sweetcorn,

Since yours is a '99 model, I will assume you have the concentric drive. What you will have to remove is the belt housing cover, drive and driven pulleys, and belt housing backing. On my xplorer, I had to loosen both floorboards so they would swing out, but I know the scrambler is different, so I don't know what to say about the floorboards. You will need a 1-3/4" socket to remove the swingarm mounting bolts. You will also have to remove the brake caliper from it's mount, as well as the lower shock bolt and the chain. Once all this is removed, the swingarm comes right out. You will then need an additional 2" socket to break the right side nut off on the swingarm.........this allows you access to the bushings. I think the bushings are less than $5 each from Polaris, and you will need 3.........2 on the right side (it is a split bushing), and 1 for the left side. Your bushing pivot pins are most likely worn as well, and they're more expensive. When I had my bronze bushings machined, I got the machine shop to machine the pivot pins down smooth before sizing the bushings to fit them. This gives the bronze bushings a smooth uniform surface to ride against. The machine shop also cut grooves in the bronze bushings for the grease to flow through, for proper lubrication. When you put it all back together, use some Loctite 262 (I think that is what I used, but not positive). Polaris recommends using a loctite primer before application of the loctite, but I couldn't find any......I just cleaned it real good with brake parts cleaner that leaves no residue. Tighten everything back as tight as you can get it, and let it sit for at least 24 hours before you try it out. This will allow the loctite to set up properly. If you have any questions, let me know.

Waylan

 

Sweetcorn,
I had the same popping noise on my Xplorer. It sounded like it was coming from the front sprocket or tranny. I looked over the sprokets for broken or bent teeth and ckecked the chain for damaged links. Everything looked fine so I was taking it in to the dealer (still under warranty). I told him what it was doing and he took it for a ride around the lot, came back and said it sounded like a broken roller on the chain. I told him I already looked at it but we jacked up the back and rotated the chain real slow and sure enough one of the rollers was gone. As loud as it was popping I was sure it was something major, but it was just that roller. And it was hard to see. He also said that the chain had a streched spot in it that would cause the tension to change when you would roll it from one position to another. I just wanted to throw that out to you if changing your bushings don't help.

 

thanks for the info, I don't think it is the chain, I put knew sidewinder chain and sprockets last fall. But the bushings and bearings need replacing for sure so I will try that and see from there.