6ocyclehum

I've got my eng compartment pretty torn down, replacing much rubber and trying to address everything I can while it's easier....I have pretty new (bought the car 2 months ago and they had just been put on) balance + timing belts. The balance belt whirrs like a supercharger- it's LOUD. It's gotta be too tight, and I had hoped with use, it would stretch some and quiet down, but I've put 1500 miles or so on it, and I still can hardly hear the engine.
Looking at the adjustment procedure, it looks like the lower tensioning roller is the one to adjust (?). Can I slightly loosen this belt without screwing anything up? I don't have the "special tool" (not for this job anyway.....). The cover is right there staring at me, I know now's the time to pull it, but I don't want to mess up the adjustment, just very slightly loosen it. Is this possible? Or when I loosen the adjusting roller, will I need to completely re-tension? Looking at the diagrams, I'm not sure how the pressure is applied for a tensioning without the tool.
Is this a reasonable DIY?

Mitch

Van

Sure. It should be almost "loose". It really needs very little tension.

FRporscheman

I run mine fairly loose to stop the whining sound. Not so loose as to fall off but just a little bit looser than spec.

6ocyclehum

Am I right about the adjustment? Loosen lower roller?
THX-
Mitch

FRporscheman

You can do either the lower one or the upper one, but the lower one is supposed to take up most of the tension. I never really understood why the upper eccentric roller is eccentric.

special tool

Yes.
Also - make sure that there is no obstruction that the belt is hitting.
The way you describe it is unusual.
Exsessive loudness can be caused by a missing 6mm (10mm ATF) bolt wedged against the belt covers, that the belt now touches.

6ocyclehum

Thanks, I'll use the lower roller to adjust and will check for anything stuck in there.

6ocyclehum

Just thought I'd follow up on this for the archives.

After some trial and error, I adjusted the balance and got rid of the loud whine! It was coming from the idler pulley, probably not being in spec with the roller directly below it (supposed to be .005" clearance). I though it was coming from the idler touching the longest part of the belt, adjusted that, no change, loosened belt, no change, then checked the clearance on the idler to roller below and that fixed it. Could also have been a combo from loosening.
The idler to lower roller is hard to see/notice working from above and I missed noticing the possible rubbing my first couple tries.

Sounds much better!

chris951

yeah, I just did belts, seals, tensioners, rollers, waterpump, and hoses. Talk about a fun DIY. You might want to invest in the Arnworx tensioning tools, very precise and easy to use. The balance belt is supposed to be kinda loose. The first time I did timing and balance belts, I had it way too tight and it whined like a bitch. FYI the '87 and later timing belt spring tensioner is hella easy tension.