a 944 pretty much means knowing something about the timing and
belts. This page
is intended to provides some insights on tools & methods for
setting the belt tension. Its funny how these belts exist
in countless other cars but on the 944 they take on a whole new
level of dread. Some feel the belt failures are the 944's Achilles
heal while others see them as no big deal. No matter where you
stand in this mix, there is no question that the 944's belts
require a bit more maintenance than other cars.
First, getting access to the
belts is a challenge in itself.
is a drawing of the belt layout used in the 83 through 86 944.
belts be replaced every 30,000 miles and be re-tensioned at about
1500 miles following replacement. Porsche offers a couple of tools
to set the belt tension and you should be able to pick these (below)
up at your local dealer for $600 to $700. If this seems reasonable,
get the maintenance manuals while you're there (for another $400)
and forget about trying to do this little job on the cheap.
interested in a different approach and saving a few bucks then
read on. Items
1 & 2 above
are the functional equivalent of this little tool known as the
The Krikit is an ingenious
little device that can quickly and accurately determine your 944's
belt tension. I don't have exhaustive studies or lab analysis to
back up this claim but I am convinced that it works and since so
may others have recognized it as an alternative, I offer it for
your consideration. This page is meant to help you to know how
you might use it. You
should also be familiar with the specifics for setting your belts
- I'm only touching on the general steps here to demonstrate
the tool. Here is a
link to Clarks Garage and a step-by-step procedure for tensioning.
here a couple of photos of how to orient the Kriket along the belt.
photos are of
the cam belt and the balance belt. Note that on the photo of the
balance belt, 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 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. But in testing with it, I found the tool to consistently
measures down to as low as 26 pounds. 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 only takes a few tries to get the hang of it.
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, that 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.
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.
mentioned it but you should have your cam positioned at about a
If you're making changes to the the timing belt tension, it's best
to rock the cam by a couple of degrees each way and then back to
the 1-1/2-tooth-before-TDC position. Then recheck the tension using
the Krikit. This rocking ensures the belt tension is distributed
evenly around the belt. The rocking is not needed though 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 rpeat this tighten, then measure cylce 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.
the balance belt re-tensioned, I only need to get the idler back
in place before
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.
photos make the access appear easier than it actually is. Working
in this tight area is a pain, but you'll get the hang of that too
with a little patience. You can see here (above) that I'm using
an older version of one of my roller wrenches. This is because
a standard wrench will not fit, at least not from many approach
angles. What's worse, as you tighten the anchor nut, the off-center,
adjusting nut tends to turn along too and alter your carefully
chosen setting. Click here to order your Krickit Tool and Timing Belt Wrench Set
is the belt layout for many others of the 944 series. In the center
is a device
as an auto-tensioner. This will auto-magically set your timing
belt tension. You'll need the Krikit (or something similar) for
setting the other belts though.
I mentioned the Porsche recommendation for belt change intervals.
concerning how often the belts should be changed, Gates (a company
who make belts) recommends a longer interval. This clipping (below)
is taken from Gates' manual on recommended belt change intervals.
last note about the AC and power steering belts. The Krikit can also be used on
V-belts. I've found that Krikit readings of 50 for the AC and 40
for the power steering to be sufficient for my street driving. That
is on the low side for some though.
If you check your V-belt tensions,
remember, check along the longest span. For the AC this is between
the AC compressor and the crankshaft. Either span of the Power
steering belt will work equally well.