84 928 crank pulley keeps loosening
#1
84 928 crank pulley keeps loosening
MY 84 Porsche 928 S crank pulley keeps coming loose and currently has .5 inch of play in each direction. All lights come on when car is started, no power steering or anything on start up. What can I do to fix this? replace pulley or replace harmonic balancer? Both?
#2
Administrator - "Tyson"
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Are you torquing it to 295Nm (218.5ft-lbs)?
#3
Not sure what the shop torqued in to when they fixed it last but it came loose 6 months ago and I had it fixed right away but its loose again and the shop feels the timing system "needs" replacing but doesn't want to look at it and tell me what's wrong, so I am on my own as far as diagnosing the issue and fixing it. Just not sure if anyone else has ever had this happen before?
#4
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Use a new bolt, torque it PROPERLY.
Properly torque bolts do not come out.
Yes, its happened before, because not torqued enough.
Ask them to show you the torque wrench they used, does it read that high? If not..there's your answer.
Properly torque bolts do not come out.
Yes, its happened before, because not torqued enough.
Ask them to show you the torque wrench they used, does it read that high? If not..there's your answer.
#6
They claim to have torqued it to Porsche specs at 218 ft-lbs and he gave me that number so I would assume it was right any other ideas on cost for parts, repair procedures, tools to use etc? They said they would charge me $1000 plus so that's out of the question for me currently.
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#9
Chronic Tool Dropper
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VERIFY that the washer on that bolt is installed in the correct direction. It has a cup that fits over the end of the crank nose to clamp the pulleys and balancer in place. If it's backwards, it will appear torque up correctly, but isn't clamping the pieces. You'll get the play you are reporting.
You'll want to replace at least the main pulley. likely the drive AC pulley. If the balancer has been walking around on the crank nose at all, it will need to be replaced too.
If the original work done on the car was done by a reputable shop, arrange with them to have the bolt taken out while you are there to observe, and with another witness. With that washer on backwards, they may be liable for the repairs needed. If all they were asked to do originally was "tighten the bolt" then it may not be their fault. Use your best judgement.
Used pulleys and balancer come from 928 International, if you need them.
Please report back your findings.
You'll want to replace at least the main pulley. likely the drive AC pulley. If the balancer has been walking around on the crank nose at all, it will need to be replaced too.
If the original work done on the car was done by a reputable shop, arrange with them to have the bolt taken out while you are there to observe, and with another witness. With that washer on backwards, they may be liable for the repairs needed. If all they were asked to do originally was "tighten the bolt" then it may not be their fault. Use your best judgement.
Used pulleys and balancer come from 928 International, if you need them.
Please report back your findings.
#10
Bob is 100% spot on.
#11
Alright will do guys, the shop is not wanting to deal with the car at all. I have a good friend whom is a mechanic for VW he has a greed to help me make sure everything is repaired correctly. This shop did a $2000 tune up on the car for me last year and replaced the a/c belts etc. so I know they were the last ones to deal with the car before the pulley came loose the first time. The pulley that has the a/c and alternator belt on it is bent up at the outer edges towards the fan and I am not sure if this is due to wiggling or if they did this when they tightened the pulley. I will likely just replace both the pulley and balancer anyway just to make sure this doesn't happen again. Is there a part # for that washer just in case it is missing? or do you know the size?
#12
Rennlist Member
Good grief. Never take your car back there. IMHO you could never trust them to redo the job properly, whether they admitted they screwed up initially or not. Where are you located? Might be someone close by who can help. And with dr bob, Sean R and others here to help, this will turn out to be a problem that's not so hard to deal with, I think.
#13
I wonder if the shop didn't have a flywheel lock tool and just had one guy hold the pulley with a pair of vise grips while the other guy tried tightening the crank bolt? That would definitely result in a chewed up pulley and a loose bolt.
#14
Well the car is in Ringgold, GA. I'm here for military training, luckily my parents have a house here I can store it at. I currently live in Alabama. Any advise will be greatly appreciated. Thanks guys.