Drive Belt / Removal / Tension / Alignement

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  • That is something I haven't considered. I'm not sure how I can check the alignment of the swing arm to the frame without some special jig set up. I believe the swing arm has bearings on each side. I have seen posts that said they had to replace the swing arm to fix the rear bearing failing which I would assume is a factory machining error.


    The next thing I was thinking to do is to remove the drive shaft and see if moving the angle drive forward to get the belt tension set will let the two sprockets stay aligned with each other. I can only move mine forward so far and it seems to be stopped by the drive shaft but that leaves the belt a little on the loose side. I've been avoiding taking the whole swing arm and angle drive out but that looks like where it is heading.

    Having had my swing arm off and installed myself, it would be my guess that your issue lies at the angle drive not being square and that is where I would concentrate my efforts. The pivot shaft has a needle bearing on the belt side and a ball bearing on the opposite. The assembly of the pivot shaft, bushings and bearings makes it nearly impossible for there to be a issue in that area. The only issue in the pivot shaft might be the snap ring holding the drivers side bearing, but you stated that the swing arm does move right and left so I doubt this is broke or missing. The first area of suspect in the swing arm would be the needle bearing on the pulley side of the rear axle in which you have made no comment and I assume is in good condition. This bring me back to the angle drive alignment being suspect. I had used lasers to align pulleys and belts on motorcycles and worked very well, especially when doing wide tire change outs. I have not needed to do this as of yet on the slingshot, but I would place a line laser square on the angle drive sprocket and take measurements from the front and back the rear drive pulley. I would prove first the pulleys are not parallel before tearing apart. Your comments does lead me to believe something is wrong in the angle drive area especially when you cannot move the drive forward enough to get the belt tight.

  • I had the same problem with movement until mniron outlined the procedure. I had read in numerous places that you need not adjust the pivot shaft if only adjusting belt tension. Made a big difference for me but still took some effort to move. I guess that there was some corrosion in the slot.
    See the pix in post #7 above. Polaris lists #2 as "Bushing, Pivot, Ball" and #18 as "Bushing, Needle, Axle". The bushings encapsulate the 2 bearings on the left side of the pivot shaft. They can't be there just for bearing retention as #3 is a retaining ring. I haven't disassembled the swingarm but the drawing makes it look like the bushings ride inside the bearings which would make them a bearing surface. Bushing 18 on the axle looks like it fits into bearing #17. If they do insert into the bearings and you have any wear on those, you can't get the sprockets parallel.


    Don't know how far your dealer is from you but I would be talking to the repair tech before I pulled the shaft.

  • mniron, Are those bushings inserts in the bearings?

    The two #2 bushings locks the ball bearing inner race, frame and angle drive together. The #18 bushing is actually the inner race of the needle bearing of the axle. Minor wear of the #18 bushing would not throw off the alignment noticeably, it would however if the needle bearing failed and bushing worn. There would be noticeable movement in the rear wheel at this point of failure. The #6 bushing locks the right side of the angle drive and frame, it is also the inner race for the needle bearing. The swing arm moves right or left on the #6 bushing by turning the pivot shaft from the drivers side in or out, the ball bearing with the #2 bushings and the #3 snap ring moves the swing arm right or left.

  • Folks, this is a subject I like and want to help understand the Drive Belt Adjustment. I have created two videos to explain what I have learned. I see from the post that all are having problems with Belt Alignment. I had the same problem understanding how to get the proper adjustment. That is why I have two videos. Watch them both and see if I give you the knowledge needed to perform Drive Belt Adjustments. Do not attempt unless you have a torque wrench rated at 200 lbs.


    This video follows my first video in which I did not understand the Drive Belt Alignment adjustments.


    This is my first video of explaining the Drive Belt Adjustments, but found I could not explain the Belt Alignment and expressed that.


    Now you have what I know and i feel with the proper tools we can make these adjustments. I will be producing a how to video soon of how to properly adjust the Drive Belt.

  • The Pivot shaft has fine threads on the drivers side, when you loosen the oposite nut and retorque to 20 ft/lbs this allows you to use the 22 mm allen head socket and turn the shaft in or out, there by moving the swing arm left or right. The threads are very fine so they do not move all that much with each turn. I found that when moved the swing arm to the left (toward the driver) the oposite nut would get tighter and have to be retorqued by backing off and then resetting to the 20 ft/lb value. I was able to get the belt moved to the exact location but it is surprising how many turns I had to make to get it to move.


    I also wiggled the tire left and right as i did this and watched the belt alignment as I turned the tire. At first nothing but then slowly it started to move. After all is done I then set the torque to 190 ft/lbs and all was good. I also reset the tension to 1" of play. The following weekend the dealer replaced the swing arm, when I got it back I noticed that the belt was as tight as a drum!. The dealer must have set the tension while the wheel was in the air. The belt is off center as well, being much closer to the right then the left. It goes back this weekend so I will point this out.


    On another note, my traction control light is now on all the time. It turns out some swing arms may have the bearing in backwards which causes this problem so I will let them know about this too.

  • Is this belt where it should be or is it offset?

    It is possible, the belt should track on the left side of the rear pulley and should not chirp, squeal or make any noise when you accelerate or slow down. Where it tracks on the front drive pulley is not as important.