Aussie944S Posted 3June, 2013 Report Share Posted 3June, 2013 Title says it all got home, parked her in the garage bout to do my pre shut down procedures and "SQUEALING" like girls at a Justin beiber concert was coming from my engine. There is no high schools on my was home so I couldn't have collected any in the grill...... Anyway I pulled her down found the problem to be the big round thing at the front of the engine that has the belt for the alternator and a/c around it. That thing was all wobbly and had caused the belt to pop off its first ridge so I put the belt back on and pulled the thing back to where it looks like it should sit and tightened up the belt. Soooo might sound like I have no idea what I'm doing and there is some truth to that but I followed the repair manual but the only thing that concerns me is that It doesn't explain if that thing is meant to have a little give back and forth like mine does when the belt is loose. Can you educate me... someone..... Cheers Link to comment Share on other sites More sharing options...
Russ Posted 3June, 2013 Report Share Posted 3June, 2013 I don't think the pulley is meant to be loose on the shaft. there might be a grub screw or something to tighten it up? Link to comment Share on other sites More sharing options...
tazzieman Posted 3June, 2013 Report Share Posted 3June, 2013 but the only thing that concerns me is that It doesn't explain if that thing is meant to have a little give back and forth like mine does when the belt is loose. Can you educate me... someone..... Cheers End play is measurable , but not scientifically by "feel". The question is , how did it become loose? I would get it checked by a competent mechanic ASAP. Just in case. Think what is connected internally to that pulley. Link to comment Share on other sites More sharing options...
tazzieman Posted 3June, 2013 Report Share Posted 3June, 2013 I don't think the pulley is meant to be loose on the shaft. there might be a grub screw or something to tighten it up? Link to comment Share on other sites More sharing options...
Russ Posted 3June, 2013 Report Share Posted 3June, 2013 you can normally tell the difference between end float and a loose pulley though right? for some reason I'm reminded of Edd on Wheeler Dealers after Mike checked the end float of a beetle engine, and the Edd checked it and you could see the thing move! Link to comment Share on other sites More sharing options...
tazzieman Posted 3June, 2013 Report Share Posted 3June, 2013 First tighten the #19 screw , then wiggle again! Link to comment Share on other sites More sharing options...
Greg944 Posted 3June, 2013 Report Share Posted 3June, 2013 Two toons here: the bolts that attach the belt pulley (17) to the toothed belt drive sprocket (14) are loose or the main bolt (16) that holds everything to front of crank is loose. IIRC the front bolt (16) can work loose over time. Cheers Greg Link to comment Share on other sites More sharing options...
Aussie944S Posted 3June, 2013 Author Report Share Posted 3June, 2013 Cheers lads, The car squealed once after start up, kinda like a mouse squeak. Then ran smooth and sounded great. Still worried though, ill pop into a bloke down the road today to have a look for me. The job is a PITA, when you only have jack stands. Link to comment Share on other sites More sharing options...
Aussie944S Posted 4June, 2013 Author Report Share Posted 4June, 2013 Right lads, Porsche engineers and there awesome German brains, thought it would be epic to make that pully 17# with a rubber holding ring. So this rubber ring has failed which means it occasionally holds the outer firm and spins normal but cause it has failed the belt has been digging into the belt cover housing behind it due to the outer piece slipping forward and backwards. So...... what have I found.... lads in USA and Europe have access to this part which is called a rubber centered crankshaft pulley or by the PET a damper. This stock they have is very small as its no longer made cost is around US$600. But giving a few guys in the USA and AUST a call that are the gods of 944 have explained that if I want to spend my coin on it I can but the best option is to run the standard crankshaft pulley. From what I have learned is that the S was a little test platform for its bigger brothers the S2 and 968, and from what we can guess is that they may have thought the car with its DOHC may need a damper on the crankshaft pulley so that it will not cause other problems, as it seems that it wasn't needed the part was no longer made after 1991, and therefore superseded by the standard pulley found on 951, 952, 968 cars. But if your rocking a 3L S2 from 1989 to 1991 get your head under the car and check to see if you have this rubber pulley, I ask this to prevent heartache later cause if you check the PET for the S2 it will display both parts pulley and damper, and from what the lads have said they are still finding some on S2 built in 1992. This YouTube vid explains and shows what's happening, he calls it a harmonic balancer but that is not what its called Cheers guys, also big shout out to James for hooking me up with a new pulley. Link to comment Share on other sites More sharing options...
JustJames Posted 4June, 2013 Report Share Posted 4June, 2013 Good post Aussie944S (even before I got a mention) Link to comment Share on other sites More sharing options...
Aussie944S Posted 6June, 2013 Author Report Share Posted 6June, 2013 New part in. Cheers James Old part... apart... Link to comment Share on other sites More sharing options...
Dubai944 Posted 6June, 2013 Report Share Posted 6June, 2013 Don't be so quick to discount the value of this part. Actually it's purpose IS to act as a harmonic balancer. The damper pulley is standard on S2's but not used on 968s, however, it's a better part than the standard pressed pulley, so although yours has died and needs to be changed, I don't recommend anyone who has one of these type of dampers in normal condition get rid of it. Yours may be an older version as the S2 version normally has 8 bolts which is better. If anyone doesn't want theirs, post them to me and I will make a nice profit selling them to all the racers in the know. Race teams make sure they use the S2 pulley on most 3 litre engine build. I was warned to use one when I built my first 968 race motor, but didn't bother. Over the first race season I cracked an oil pick up, broke four belt tension rods and had quite a few bolts keep backing out. Karl from Racers Edge gave me the, "I told you so" lecture and I then fitted the S2 pulley and had four years without any of those issues, no other changes. Clearly there is a harmonic issue with these engines that is very evident when you subject them to high rpm. For a normal road engine you might not notice the benefit and the standard pulley might seem maintenance free, but the S2 type pulleys don't normally separate. Mine has been on my race engine for 5 years and is subject to full throttle 7500rpm+ driving constantly and shows no signs of threatening to come apart. Edit: I should also add that the reason they discontinued the use of the damper on the 968 was because the 968 has a dual mass flywheel to address the same problem. If you have a solid flywheel, you are better off with the damper. Link to comment Share on other sites More sharing options...
Aussie944S Posted 6June, 2013 Author Report Share Posted 6June, 2013 Valid points, you raise here with reference to high rpm race builds didn't have that in mind when I typed away last night and i probably should have been more clear and said "to get you to your next center link appointment" this will work. As for my part its done its job for the last 25yrs and decided to end itself. For the rest of it IMHO. Link to comment Share on other sites More sharing options...
Greg944 Posted 6June, 2013 Report Share Posted 6June, 2013 Thanks for that. I have just filed that info away for the future 944S rally motor! Cheers Greg Link to comment Share on other sites More sharing options...
Aussie944S Posted 6June, 2013 Author Report Share Posted 6June, 2013 Rs barn have one developed for 944. Don't know prices but they say its for supercharged 944s would also do the job of the NLA part on a street car Link to comment Share on other sites More sharing options...
Dubai944 Posted 6June, 2013 Report Share Posted 6June, 2013 Aussie, yes I think you will get away with using the non damped pulley fine for normal driving and particularly as you are driving an S with the smaller motor capacity. Everyone just needs to be aware that the bigger 3.0l motors on the S2 and 968 definately have some unique harmonic issues and those issues are present during normal driving. It's not something you can feel but it's there and it was enough for Porsche to fit a damper on the S2 and a dual mass flywheel on the 968. Race experiences like mine are quite common and just highlights the problem. Anyone with a 968 that changes to a high performance flywheel should try and get an S2 type damper, and anyone with an S2 shouldn't get rid of their damper, or if it comes apart, should try and find another one. Definitely a problem with the parts getting so old now that the rubber rings probably aren't going to last forever. That's why good ones are becoming a sought after part. It would be good to find a source for supplying a new part. I was looking to have a custom damper made by ATI at one point, but they prefer the single crank bolt attachment used on typical V8s and didn't like the multiple small bolt through attachment method that Porsche pulley uses and weren't interested in doing it. Link to comment Share on other sites More sharing options...
Aussie944S Posted 7June, 2013 Author Report Share Posted 7June, 2013 If I could throw my whole dole cheque at it I would, but this little Aussie battler got some kids to feed... haha Im keeping my eye on http://www.rsbarn.com/ with there damper/ harmonic balancer. But I still suggest ppl check there's as when they go, the belt rips things apart and the outer steal ring starts chewing the balance belt and the balance pulley. Anyhow peace out. Link to comment Share on other sites More sharing options...
Dubai944 Posted 9June, 2013 Report Share Posted 9June, 2013 Got in touch with Pete at RS Barn and he told me the new balancers he is getting made are still being manufactured so not yet available. The new part will be heavier than the original based on analysis that the original was too light for the 3.0 crankshaft. The new one is also rebuildable. He says it will retail for less than the OE part, but hasn't given me a price yet so probably still not cheap. Good to know there is an option available now. Pics of the new part compared to the old S2 part below. Link to comment Share on other sites More sharing options...
Aussie944S Posted 9June, 2013 Author Report Share Posted 9June, 2013 Cool pics mate. Looks like there is a bit of a difference between mine and the S2 damper as it looks different in the rubber size part. The people manufacturing the part for RS Barn is BHJDynamics.com. If its cheaper than the $580 delivered I've been able to find for the original part I'll be happy. So far I've put 350km on the new solid pulley and to be honest, the only difference I can feel is.... nothing... as for noise I should have realised the part was failing. Cause with the new pulley I can actually hear the engine sucking air through the air filter. If you get one before me Dubai944, let me know as I've got my mind set on other stuff now the car is all good. Link to comment Share on other sites More sharing options...
9fan Posted 9June, 2013 Report Share Posted 9June, 2013 Interested also - Cheers,Mark. Link to comment Share on other sites More sharing options...
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