Timing Belt Tension Poll....

[stitch2k1]

Needless to say, I like torque wrenches. I've had a few of them calibrated a few years ago (and they were predictably way off). The snap-on dial wrench is for engine assembly and gets calibrated before engine builds. My go-to is the Snap-On digital wrench for everyday wrenching.

I need to pick up a nice dial wrench for that reason, I also see a 3/8 digital in my future for being lazy.

[dkofearl]

I must say, I’m quite awed by your concept here, Tom…simple and elegant. I would enjoy testing/calibrating your model against my Arnnworx. As I am an old guy unable to comprehend the mystery of 3D printing, please let me know when you patent and start marketing these gems.
Kindly,
Earl

[1987-944]

I recently bought an ArnnWorx 920X v6.2 tool. Per the instructions the range for a new cam belt should be .185 to .189. I calibrated it with the calibration bar to .164. Put it on my 87 944 with the auto tensioner. If I am reading the dial correctly to get to .192 I have to allow the tensioner to exert full spring pressure on the belt. This seems like too much tension to me. On the other end when I completely relax the auto tensioner the ArnnWorx indicator shows almost .223. Any ideas? I have the tension gauge positioned correctly and backed off one and a half teeth from TDC on the cam gear. Thanks for any and all input. [/img][/img]

[Tom]

I recently bought an ArnnWorx 920X v6.2 tool. Per the instructions the range for a new cam belt should be .185 to .189. I calibrated it with the calibration bar to .164. Put it on my 87 944 with the auto tensioner. If I am reading the dial correctly to get to .192 I have to allow the tensioner to exert full spring pressure on the belt. This seems like too much tension to me. On the other end when I completely relax the auto tensioner the ArnnWorx indicator shows almost .223. Any ideas? I have the tension gauge positioned correctly and backed off one and a half teeth from TDC on the cam gear. Thanks for any and all input.

Why do you think the spring tensioner is applying too much pressure on the belt? On my current motor, when I fully release the spring tensioner and let it apply its max pressure on the belt, the belt is still a little looser than the factory spec. So on my motor, I need to add a little pressure to the spring tensioner to get the belt tension up to spec. Bottom line, if your only concern is that you need to let the spring tensioner exert its full pressure to reach the Arnnworx spec, then I think your concern isn't well founded. That's very often true. Do you have any other reason to think the belt is too tight? The Arnnworx tool is a really well-designed, precision tool in my opinion, so if everything else seems right and that tool says the belt is in spec, you can have a pretty high confidence level in it.

[1987-944]

Yes, .192 is at full spring pressure. To get it to .185 per ArnnWorx instructions I also need to give the tensioner a push past full spring. Last time I changed the belt I just locked the auto tensioner down at full spring pressure. Never had any issues. This time I wanted to be more exact. Yes I too like ArnnWorx tools as I have Bruce’s rear wheel bearing press, pin wrench and flywheel lock. All quality tools! Still looking for input from actual users of this specific tool. Thanks for your input Tom.

[Tom]

Yes, .192 is at full spring pressure. To get it to .185 per ArnnWorx instructions I also need to give the tensioner a push past full spring. Last time I changed the belt I just locked the auto tensioner down at full spring pressure. Never had any issues. This time I wanted to be more exact. Yes I too like ArnnWorx tools as I have Bruce’s rear wheel bearing press, pin wrench and flywheel lock. All quality tools! Still looking for input from actual users of this specific tool. Thanks for your input Tom.

I have to nudge mine past its full spring extension too. Hoping others chip in and give you more comfort. If it helps, I have both the Arnnworx tool and a factory 9201 and my Arnnworx tool is dead-on accurate vs. the 9201. Not that it makes me an expert, but I also wrote an article for Panorama Magazine comparing all available timing belt tools, and the Arnnworx was the only tool that accurately and consistently set the belts to factory specs (other than the 9201 of course).

[1987-944]

The photo on the right in the instructions does not make sense. I have no problem with the calibration photo on the left. Also compare the loose belt and tight belt arrows on photo to belt tension specs in instructions along with cam belt range on photo to instructions. It is confusing. This is why I’m asking questions.

[Tom]

The instructions have been updated since I got mine. Did you try to contact Bruce, aka @52Megahertz here on Carpokes...?

[1987-944]

Yes. E-mailed him. Had been in contact with him since early this evening. Unbelievable customer support!!! Issue resolved. The instructions need to be revised to match the new version of the tool.

[danmartinic]

Check out this built-in tension gauge on the Renault dci motors... you get some French inspiration Tom? LOL



*Start at 3:57* .. intended clip is about 2 secs long

PS.. I'm currently in Europe and looking at replacing the belt on my Renault.. almost fell over when I saw this