Timing Belt Tension Poll....

Naturally aspirated tech and talk

What do you use to set the tension on your 944 timing belt?

Factory 9201 Tool
8
17%
Arnnworx tool
16
34%
Krikit tool
1
2%
By feel and/or 90 degree twist/water pump slippage
18
38%
Factory spring tensioner/Other
4
9%
 
Total votes: 47
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Tom
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Darwin wrote: Sat Jun 18, 2022 7:53 pm
Latitude48 wrote: Sat Jun 18, 2022 5:03 pm
Darwin wrote: Sat Jun 18, 2022 1:10 pm My auto tensioner always over tensions my belt. I have one of the early arnworx tensioning tools before he switched to the one that looks more like a 9201. Works great, with no complaints here.
I've compared the spring tensioner on my S2 against the result using the P9201 tool and it's been "close enough." My new belts are due for a recheck soon and I'll make another comparison to see if it's still good.
Nice. I'm not saying all tensioners are bad, but I feel like relying solely on something like that when literature doesn't say to do so is potentially asking for trouble. I'm sure with the manufacturing variance in springs, you can check to see where the tensioner puts it, but to say they all put it where it needs to be is a little too trusting IMO.
I've checked my tensioner against my 9201 as well and it consistently tensions my belt to about 2.0 to 2.2 on the gauge. I give it a little nudge to tighten the belt and can often get it in spec on the first try. But that only works because I know MY tensioner vs the factory gauge -- and the amount of tension these things apply does seem to vary from one tensioner to the next. I assume the factory was shooting for them to put the belt within the spec, but corrosion, wear, grime, etc. all conspire against it over time. Even though my tensioner always seems to need a little nudge to be spot on, I always check with the 9201 anyway, since I have it, and since I'm convinced the one time I don't check it will be the time the tensioner hangs up on something and is way out of spec (although I'd probably notice that by feel, but paranonia knows no bounds.... :lol: ).

#21

Crazy Eddie
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I use a buddy of mine’s …. 9201
His name is Tom . You may have heard of him🤔

#22

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Tom
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Crazy Eddie wrote: Sun Jun 19, 2022 3:24 pm I use a buddy of mine’s …. 9201
His name is Tom . You may have heard of him🤔
And you are WAY overdue I might add.....

#23

Crazy Eddie
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Tom wrote: Sun Jun 19, 2022 3:31 pm
Crazy Eddie wrote: Sun Jun 19, 2022 3:24 pm I use a buddy of mine’s …. 9201
His name is Tom . You may have heard of him🤔
And you are WAY overdue I might add.....
Very true .🙄

#24

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For the balance shaft belt I use the twist method, even though I have the Arnnworx tool. Until I was corrected about this recently, I thought that this was, honestly, good enough since the belt is so loose anyway.

I have to have my head redone, likely, so I'll have to go through everything again and will have the opportunity to check everything out with the Arnnworx tool, so hopefully I'll start to develop some finger feel.

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#25

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I have the Arnnworx tool and only bought it because every other method I tried left me with a lot of belt whine so I figured I wasn't getting the correct tension. I have used the Arrnworx tool, the Krikit tool, a spring loaded generic tool and the twist and feel method and while I feel the Arnnworx tool is highly accurate and the best of the bunch I still have a lot of belt whine after using it. It's also ironic that when using the twist and feel method I'm less than 5% difference in tension from the Arnnworx tool so my hands seem to be very well calibrated!
Dan

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#26

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Tom wrote: Sat Jun 18, 2022 3:28 pm So for the people who don't use the factory tool or the Arnnworx, what do you do for the balance shaft belt??
Feeler gauges.

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355 wrote: Mon Jun 20, 2022 7:46 am I have the Arnnworx tool and only bought it because every other method I tried left me with a lot of belt whine so I figured I wasn't getting the correct tension. I have used the Arrnworx tool, the Krikit tool, a spring loaded generic tool and the twist and feel method and while I feel the Arnnworx tool is highly accurate and the best of the bunch I still have a lot of belt whine after using it. It's also ironic that when using the twist and feel method I'm less than 5% difference in tension from the Arnnworx tool so my hands seem to be very well calibrated!
If you are a PCA member, check out the article "Tensions Run High' in the May 2018 issue of Panorama Magazine (by yours truly). It comes to the same basic conclusion -- i.e., the Arnnworx tool is the only tool tested that reliably replicates the factory tool.

Belt whine is typically caused by the balance shaft belt, and happens when the belt is toward the high end of the factory spec and/or tighter than the spec. Keep the 18mm balance shaft belts toward the lower end of the range (3.0) on the factory tool and they won't whine. :) If you set it to the higher end of the range (4.0), it will definitely whine, at least for a while.

#28

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Tom wrote: Sun Jun 19, 2022 9:27 am
Darwin wrote: Sat Jun 18, 2022 7:53 pm
Latitude48 wrote: Sat Jun 18, 2022 5:03 pm
I've compared the spring tensioner on my S2 against the result using the P9201 tool and it's been "close enough." My new belts are due for a recheck soon and I'll make another comparison to see if it's still good.
Nice. I'm not saying all tensioners are bad, but I feel like relying solely on something like that when literature doesn't say to do so is potentially asking for trouble. I'm sure with the manufacturing variance in springs, you can check to see where the tensioner puts it, but to say they all put it where it needs to be is a little too trusting IMO.
I've checked my tensioner against my 9201 as well and it consistently tensions my belt to about 2.0 to 2.2 on the gauge. I give it a little nudge to tighten the belt and can often get it in spec on the first try. But that only works because I know MY tensioner vs the factory gauge -- and the amount of tension these things apply does seem to vary from one tensioner to the next. I assume the factory was shooting for them to put the belt within the spec, but corrosion, wear, grime, etc. all conspire against it over time. Even though my tensioner always seems to need a little nudge to be spot on, I always check with the 9201 anyway, since I have it, and since I'm convinced the one time I don't check it will be the time the tensioner hangs up on something and is way out of spec (although I'd probably notice that by feel, but paranonia knows no bounds.... :lol: ).
AFAIK none of the fancy tools figure in the engine expansion, when it heats up. The cam belt gets tighter, and knocks out the waterpump bearing prematurely. That's why I back off the cam belt tensioner, until I can just turn the waterpump pulley by hand. It's never going to jump when cold, and as soon as the engine heats up, the belt gets tighter. Changing the waterpump every 2nd belt change is nonsense really.

#29

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danmartinic wrote: Thu Jun 16, 2022 7:45 am You're missing an option for the poll: auto-set via the spring loaded tensioner (that's what I've been using since 2008 and over 120,000 miles of daily driving)

Seems to be work fine. I do take the tensioner off, clean and lubricate it before installing
I disagree with this, cause after 30yrs of age I do not think you should trust it to be accurate. I've since then seen issues with super weak ones being nowhere near spec.
Maybe ok on a personal car, but I always use a tool on a customer's car, and I keep records of everything being in spec.
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