Balance shaft belt tension

[Jacquiles]

I’m getting pretty close to finishing my 944 project and one thing that i’ve had a bit of trouble with is getting the balance shaft belt tension right. The timing belt should be close enough because i used the 3d printed tool with a snap on torque wrench and it checked out. Initially i think i had my balance shaft belt way too tight because there was a very loud whining sound. after loosening it considerably, it’s for sure a lot quieter but i feel like the belt moves around a little too much. and the whine is still present. Here is a video of it after loosening it.

[usury]

I'm interested in this too. I did my belts last fall. The balance belt was difficult for me as well.

When it was loose enough to not whine it came close to hitting the water pump pulley.

There was a fine line between too tight and whining, too loose and nearly hitting the water pump, and just right where it's still tight but not whining.

I chased it for a long time. I don't have the Porsche tensioner tool, only the "Krikit" tool (which isn't great).

[stoneguy]

Which direction are you turning the tension adjusting nut??
I had a horrible whine when I changed my belt even at the correct tension. I re adjusted the tension by turning the tensioning nut it the opposite direction and it stopped whining. can't remember if it was cw or ccw.
Just my two cents!

[stoneguy]

to follow up, the balance shaft belt and the cam shaft belt tensioners turn in opposite directions to adjust. Turn them the direction that brings them AWAY from the housing cover.

[Jacquiles]

I'm interested in this too. I did my belts last fall. The balance belt was difficult for me as well.

When it was loose enough to not whine it came close to hitting the water pump pulley.

There was a fine line between too tight and whining, too loose and nearly hitting the water pump, and just right where it's still tight but not whining.

I chased it for a long time. I don't have the Porsche tensioner tool, only the "Krikit" tool (which isn't great).

Ok so i rechecked my timing belt and it was actually a tiny bit too tight. i loosened it accordingly and the whine seems like it may be quieter. idk. probably just placebo. But either way the timing belt is tightened correctly now and the balance shaft belt is loose as it was in the video i posted, so i think i will leave them and revisit once i actually put some miles on the car. Also good to note is that my water pump is new uro parts water pump

[Jacquiles]

I'm interested in this too. I did my belts last fall. The balance belt was difficult for me as well.

When it was loose enough to not whine it came close to hitting the water pump pulley.

There was a fine line between too tight and whining, too loose and nearly hitting the water pump, and just right where it's still tight but not whining.

I chased it for a long time. I don't have the Porsche tensioner tool, only the "Krikit" tool (which isn't great).

Also after watching some videos of other people balance shaft whine… Mine is nothing in comparison . Theirs are very loud. One that i saw showed the guy driving off and you could still hear it. mine is definetely audible at 3k rpm but no where near sounding like that. And theirs was very loud at idle. mine is even audible at idle

[Hoosier924S]

I just did my T-Belt & Balance Belt and had more whine when tighter.

[Tom]

In general, it's the balance shaft that causes the whine. It whines a bit at top of the tension range (4 on the factory scale) and gets louder the tighter it gets. It's consistent enough you can pretty much guess the balance shaft tension by listening to it, at least if it is about 3.5 or tighter on the tensioner tool.

[Thom]

From what I can remember it's not really the balance belt itself that can get loud but the flat roller that is supposed to avoid the belt to flutter. This occurs when the belt is adjusted too loose, keeps in permanent contact with the flat roller thus makes it spin constantly, whence the whine.

[Tom]

From what I can remember it's not really the balance belt itself that can get loud but the flat roller that is supposed to avoid the belt to flutter. This occurs when the belt is adjusted too loose, keeps in permanent contact with the flat roller thus makes it spin constantly, whence the whine.

Not sure where exactly the whine originates, but in my experience, a tight b/s will cause the whine. I've never heard a loose balance shaft belt create that characteristic whir/whine sound.