How to Remove Crank Pulley and/or Engine Fan with Engine in Car DIY
11-09-2011, 03:52 PM
#16
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The pulleys come apart and the everything slides off. When you put the new belt on and tight the nut you are squeezing the halves of the pulley together with the belt in between. As you tight the nut the pulley halves get closer and the belt tightens.
11-09-2011, 07:40 PM
#17
Race Director
Tension of the belts is determined by how many shims are between the belt cups. They are fairly thin but there are 2 sizes of them (thin & thinner). The newer/shorter the belt is the more shims are between the belt cups. The older/more stretched the belt is the fewer shims will be used. If the shims are not needed between the belt cups they are placed between the thick spacer/washer and the first belt cup (outside the belt "channel").
Last edited by Slow Guy; 11-10-2011 at 12:52 PM. Reason: corrected terminology
11-09-2011, 11:17 PM
#18
Rennlist Member
Bill and Mike, thank-you both for the detailed explanation 
On mine the first nut on the alt. shaft is a 24mm nut (but a 15/16 box wrench works fine). Removing the nut, thick spacer washer, belt "cup", cup spacers, 2nd cup, then thick spacer washer you get access to the inner belt. This requires you to remove (3) 5mm hex cap bolts to get that belt off.
Tension of the belts is determined by how many spacer/washers are between the belt cups. They are fairly thin but there are 2 sizes of them. The newer/shorter the belt is the more spacers are between the belt cups. The older/more stretched the belt is the fewer spacers will be used. If the spacers are not needed between the belt cups they are placed between the thick spacer/washer and the first belt cup (outside the belt "channel").
Tension of the belts is determined by how many spacer/washers are between the belt cups. They are fairly thin but there are 2 sizes of them. The newer/shorter the belt is the more spacers are between the belt cups. The older/more stretched the belt is the fewer spacers will be used. If the spacers are not needed between the belt cups they are placed between the thick spacer/washer and the first belt cup (outside the belt "channel").
11-10-2011, 10:12 AM
#19
Rennlist Member
Thread Starter
regards
11-10-2011, 11:51 AM
#20
Racer
This precise explanation with pictures certainly helps to overcome hesitation to use this method.
Great way to open and tighten a stubbern big fan nut without running the risk of rounding out the hex inside the shaft.
Much appreciated.
Great way to open and tighten a stubbern big fan nut without running the risk of rounding out the hex inside the shaft.
Much appreciated.
11-10-2011, 12:42 PM
#21
Racer
Yes, great explanation. 
One still needs the triple square tool when installing the belts because the shaft needs to be turned when tightening the pulley halves for the right tension on the belt.
It takes a bit of fiddling trying to keep the belt between the halves while partially turning the shaft with the tool and tightening the big nut. Once you're close, keep turning the shaft with the 24 mm (or 15/16") which then also turns the whole engine by hand. When things look good, start the engine for a short burst, then check the tension on the belt; not too tight or loose.
Sometimes it takes a second try with changing/adding shims.
The Porsche tool kit does not contain extra shims or tools to change belts as I found out in the middle of nowhere with the then new to me 993.
The tool kit for my older 911 has the necessary tools and a better total 6 shim set-up, IMHO.
I recommend getting the necessary tools and a couple extra shims.
One still needs the triple square tool when installing the belts because the shaft needs to be turned when tightening the pulley halves for the right tension on the belt.
It takes a bit of fiddling trying to keep the belt between the halves while partially turning the shaft with the tool and tightening the big nut. Once you're close, keep turning the shaft with the 24 mm (or 15/16") which then also turns the whole engine by hand. When things look good, start the engine for a short burst, then check the tension on the belt; not too tight or loose.
Sometimes it takes a second try with changing/adding shims.
The Porsche tool kit does not contain extra shims or tools to change belts as I found out in the middle of nowhere with the then new to me 993.
The tool kit for my older 911 has the necessary tools and a better total 6 shim set-up, IMHO.
I recommend getting the necessary tools and a couple extra shims.
