Balance Shaft Idler Clearance Question
 

Finally wrapping up my gigantic belt, seal, WP etc. replacement and have a quick question about the balance shaft idler. I know the clearance is 0.5mm between the idler and balance shaft belt on the lower side but what about the upper side? Because it is possible to position the idler either slightly touching the belt on the top side or it's also possible to position it so that there is no chance of contact on the top side while still keeping the 0.5mm lower clearance. Originally I thought the mounting hole was intended to be kept vertical and then the 0.5mm was set at the bottom and the top would fall where it should but upon installation it seems that with this method the upper side makes definite contact. Maybe this matters or maybe it doesn't but just want to check to be certain. I guess with the engine spinning the top side of the belt is either stretched tight or centrifugally driven outward so maybe it never touches either way.

Thanks

I just set mine. There's a YouTube video that explains it. However, I used a credit card as a spacer to get the .5mm gap to the lower shaft, I made sure the rib of the belt was in line with the idler roller to gap it when doing it. At the top I moved it in until the roller was as close as I could get it without it touching. I used a flashlight and checked for a glimpse of light in the gap (belt rib to center of the rollers high point). Once set, I rotated the engine and saw that the belt misses the idler roller on most teeth but every few just graze it enough to turn the slightest bit. I was happy with that.

Seems people either do it like above or they deflect the upper belt the slightest bit. I've read deflecting the belt causes more shaft squeal so I decided to set it how I described. You can always adjust it later if your not satisfied with it on first start up. Here's a pic of mine close up.
https://cimg7.ibsrv.net/gimg/rennlis...44bb2bc943.png