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Timing Belt Tension Poll....

Posted: Sat Jun 11, 2022 10:56 am
by Tom
Curious to know what is most common these days....(for those to do their own belts).

Re: Timing Belt Tension Poll....

Posted: Sat Jun 11, 2022 2:15 pm
by johnb
They're not completely exclusive, since I always test by hand as well, but I mostly rely on the arnnworx tool. (The good one that replicates the factory one, not the really basic cheap one).

Re: Timing Belt Tension Poll....

Posted: Sat Jun 11, 2022 2:16 pm
by Tom
johnb wrote: Sat Jun 11, 2022 2:15 pm They're not completely exclusive, since I always test by hand as well, but I mostly rely on the arnnworx tool. (The good one that replicates the factory one, not the really basic cheap one).
Arnnworx has a really basic cheap one?

Re: Timing Belt Tension Poll....

Posted: Sat Jun 11, 2022 2:26 pm
by johnb
Tom wrote: Sat Jun 11, 2022 2:16 pm
johnb wrote: Sat Jun 11, 2022 2:15 pm They're not completely exclusive, since I always test by hand as well, but I mostly rely on the arnnworx tool. (The good one that replicates the factory one, not the really basic cheap one).
Arnnworx has a really basic cheap one?
Yeah here it is. I'm not sure if they still make it, and I definitely can't remember how to use it:

20220611_172032.jpg
20220611_172032.jpg (331.41 KiB) Viewed 3076 times

In any case it's not that good (but better than nothing).



And here's the legit one if anyone's wondering what that looks like:

20220611_173135.jpg
20220611_173135.jpg (198.31 KiB) Viewed 3073 times

Re: Timing Belt Tension Poll....

Posted: Sat Jun 11, 2022 10:30 pm
by Spring44
I had never heard of that cheap Arnworx tool before. Hard to even imagine how that works!

Re: Timing Belt Tension Poll....

Posted: Sun Jun 12, 2022 6:20 am
by johnb
Spring44 wrote: Sat Jun 11, 2022 10:30 pm I had never heard of that cheap Arnworx tool before. Hard to even imagine how that works!
You put one of the slots over the belt (there's one slot for the timing belt, one for the balance shaft belt). Then you use the tool to twist the belt, and the idea is that it measures the force required to twist the belt a certain amount. But I can't remember the exact details now.

Re: Timing Belt Tension Poll....

Posted: Mon Jun 13, 2022 1:31 pm
by Zirconocene
I voted for the Arnnworx tool, since I bought one to make sure everything is OK, but I actually just rely on the tensioner to do its job.

So, I sort of cheated on the reply.

I'm a little surprised that the 9201 tool sees as much use as it does in the poll, so far. I've always thought those things were about as rare as hen's teeth.

Cheers

Re: Timing Belt Tension Poll....

Posted: Mon Jun 13, 2022 1:59 pm
by Tom
Zirconocene wrote: Mon Jun 13, 2022 1:31 pm I voted for the Arnnworx tool, since I bought one to make sure everything is OK, but I actually just rely on the tensioner to do its job.

So, I sort of cheated on the reply.

I'm a little surprised that the 9201 tool sees as much use as it does in the poll, so far. I've always thought those things were about as rare as hen's teeth.

Cheers
My spring tensioner thing consistently tensions the belt under the factory spec -- like 2 to 2.5 on the 9201. I always have to give it a little nudge to get it up to spec. I suspect the 9201 has a higher rate here in part because we have a lot of long-time 944 diehards here. Results might look much different on elsewhere? I have an idea I'm playing with to help people get the belt tensioned to spec (or very close) without a 9201 or Arnnworx tool, so was asking just to get a sense of who is using what....

Re: Timing Belt Tension Poll....

Posted: Mon Jun 13, 2022 3:01 pm
by Spring44
Zirconocene wrote: Mon Jun 13, 2022 1:31 pm I voted for the Arnnworx tool, since I bought one to make sure everything is OK, but I actually just rely on the tensioner to do its job.

So, I sort of cheated on the reply.

I'm a little surprised that the 9201 tool sees as much use as it does in the poll, so far. I've always thought those things were about as rare as hen's teeth.

Cheers
I bought my 9201 back in the late1980-1990 period when there were no other alternatives that I knew of. It cost just north of $400 then, and it paid for itself on the first belt change that I did with it. It was pretty pricy at the time, but was not that much compared to the $1300 belt/water pump replacement cost at the dealer. I think that my purchase of the flywheel lock, the pin wrench and the offset spanner wrench added a couple of hundred more to that cost as well.

I think that I have seen the 9201 gauge going for as much as $1200 online recently but if you adjust that cost for the time-value of money, it may not be that much higher than what I paid for mine 30+ years ago.

I'd do it again though. Considering the consequences of an erroneous tensioning, using a seat-of-the-pants guess like twisting the belt just gives me the willies! Mine is an '84, so no automatic tensioner for me!

Re: Timing Belt Tension Poll....

Posted: Tue Jun 14, 2022 12:05 pm
by stitch2k1
I have the Arnnworx tool now, but I have yet to use it. I did it by hand on my first car, an 89na, and on my S2. Balance shafts were too tight, I have learned more about tensioning those since then. I need to readjust the BSB on my S2, I plan to make a video about how to use the Arnnworx tool on eccentric and spring tensioners.

Those were both spring tensioned timing belts, my S2 was so strong I had to use my pin wheel wrench and a floor jack handle to release the tension. I plan to check the tension on it as I was warned it might be "too high" but I'm thinking it's just in really good shape -- and they were like that originally.