Krikit Belt Tension Tool - How to Use & Recommended Settings

Bruce over at Arnnworks used to have a write up for how to use the Krikit belt tension tool on his site but recently I have been no longer been able to find it. To help others who may still use this tool like I do I have re-posted the tutorial on how to properly use it.

 

Using the Krikit

Below is the Krikit and the belt setting that should be used with the Krikit. 

 

 

Recommended Belt Settings

New Cam Belt: 40 lbs

Used Cam Belt: 37-38 lbs

New/Used Balance Belt: 27-28 lbs

AC/Alternator Belt: 80 lbs

 

I don't have studies or lab analysis to prove that this tool works but there are many, many 944 owners who use this tool and they frequently recommend it in the Porsche community discussion forums.  While I personally don't recommend the Krikit, I will help you to use it. 

Note: You should be familiar with the specific steps for setting the tension of your belts - I'm only touching on  the general steps  here to demonstrate the tool.  

 

 

 

First, a couple of photos of how to orient the Krikit along the belt. Above photos are of the cam belt and the balance belt. Note that on the photo of the balance belt (which has "nubs" on both sides), the contact portion of the indicator arm is directly over one of the belts nubs.  This is important for an accurate reading. When you apply thumb pressure the belt will deflect and you will see the indicator arm raise up and a click can be felt/heard. When you feel this click, immediately release the pressure and read where the indicator arm intersects the scale.

 

The above reading is 27 Lbs and very close to the correct setting for the 944 balance belt. 

Side note: when I first used with this tool, I was concerned that the Krikit would not accurately measure below the lowest scale mark of 30. This should be a concern by anyone considering the Krikit as it is seldom good to use a pressure measuring device at or near it's limits.  If you haven't used the tool before, you should make several readings (without altering the belt tension) until you begin seeing consistent readings - it may take a few tries to get the hang of it.

 

Now, on to the actual belts. The ideal place to measure belt tension is at the center of the longest span. To create a long span,  I have removed the upper timing cover (for access), the timing belt idler pulley and water pump guide rail (available only with the updated water pump). Notice how that when I apply thumb pressure through the Krikit, there is a space (see arrow) between the spanned portion of the belt and the other area of the cam belt. This small space is important, without it, you will not be accurately measuring the belt's tension. 

The Krikit quickly tells me that my timing belt tension is correctly set at 40 lbs.  I make a this reading a couple of times to be confident that I am getting a good reading. If the reading is low or high, I make the needed adjustments and use the Krikit to make another reading. Note too, how easily the small size of the Krikit works to fit into this very tight area. This is a noteworthy advantage over the other tools.

 

I haven't mentioned it but you should have your cam positioned at about a tooth before TDC. If you're making changes to the the timing belt tension, it's best to rotate the crankshaft backward  until the cam is at the 1-1/2-tooth-before-TDC position.   Doing this moves the small amount of belt slack to the upper span of the cam belt. Then recheck the tension using the Krikit. This "back-positioning" of the cam is not needed for adjustments to the balance belt.  My photo above is only meant to show the different marks. In this photo, the marks are not correctly aligned. 

 

Above, you can see my attempt to get a reading of the balance belt. As before, I've removed the balance belt idler roller to create a long, unobstructed span. In this case my tension was so low that I got an invalid reading. This is apparent because the indicator arm is extended against the stop, see below.

 

This was easily changed by tightening the balance belt tension and simply rechecking with the Krikit. I then repeat this tighten-then-measure cycle until I had the correct tension. Most people are surprised at how loose the correct tension on the balance belt is. I've found that it should be no higher than 28 pounds else there is a distinct (and irritating) belt whine. With that, I re-installed the idler roller and prepared for a engine-running inspection of belt operation.

 

With the balance belt re-tensioned, I only need to get the idler back in place before starting the engine.  Here you can see that I'm re-setting balance belt idler roller to the specified .5mm - it should not actually touch the balance belt (except during operation).