Clunking on accel/decel
#1
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Clunking on accel/decel
I developed a solid clunking on accel/decel today that I'm trying to determine if it is clutch related or CV related. It can best be described as driveline "lash".
After stopping at the entry gate to collect my parking ticket, I made a spirited exit. During acceleration I felt a shudder develop at around 5k in 1st gear and it carried through into 2nd gear.
When I backed off the throttle I felt a definite "clunk/clank" that followed throttle closure by about one second. This is very repeatable with on/off throttle.
From a stand-still there is no lash or clunk. Only when rolling and going on/off throttle.
I didn't have time to look at the half-shafts to see if there was something obviously loose so I don't have a datapoint there.
FWIW, clutch action is smooth and consistent. It was a little "notchy" at the floor a few weeks ago then straightened out and is smooth.
Also, it is definitely not the sway bar mounts. They are in tact and of the updated design.
The car has 78k miles and I believe the clutch is original.
I did a search and found a similar issue that rmlm was having but never got the impression he completely resolved it or didn't report back.
I'm out of town for a few days while the car sits so I'm open for a good debate on the topic!
Thanks in advance.
After stopping at the entry gate to collect my parking ticket, I made a spirited exit. During acceleration I felt a shudder develop at around 5k in 1st gear and it carried through into 2nd gear.
When I backed off the throttle I felt a definite "clunk/clank" that followed throttle closure by about one second. This is very repeatable with on/off throttle.
From a stand-still there is no lash or clunk. Only when rolling and going on/off throttle.
I didn't have time to look at the half-shafts to see if there was something obviously loose so I don't have a datapoint there.
FWIW, clutch action is smooth and consistent. It was a little "notchy" at the floor a few weeks ago then straightened out and is smooth.
Also, it is definitely not the sway bar mounts. They are in tact and of the updated design.
The car has 78k miles and I believe the clutch is original.
I did a search and found a similar issue that rmlm was having but never got the impression he completely resolved it or didn't report back.
I'm out of town for a few days while the car sits so I'm open for a good debate on the topic!
Thanks in advance.
#2
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I'd vote for CV's. Don't drive it until you check them. It may not be the joints, it could also be loose or missing bolts. Put it up in the air, they are easy to inspect. If one let's go, it can be dangerous and expensive. Don't drive it until you check the CV's!
#3
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One of the guys here in San Antonio had the same sounds. The bolts on the left side of the halfshaft at the transmission came out and as they did, the halfshaft rotated and hit the accelerator rod and put a hefty bend in it. This in turn caused the accelerator rod to shorten quickly and the engine rev quite high. He shut it down and had a flat bed tow it home as it was late at night. We checked it over the next day and that is what I found. Also found all the bolts in the CV joints were loose. Since those are stretch bolts, we replaced all of them and torqued them to spec. The I had to remove the accelerator rod and straighten it. I'm with Ed, sounds like CV joints. Check em out.
#4
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I hope it is as simple as torquing the bolts to get me home. It is sitting at the airport right now. I will catch a cab home and come back with tools and jack stands...... This is should get some looks.
Ron, your friend's story is pretty scary. I hope he didn't damage the engine.
I'm planning on a new clutch in the next 12 months. I'd rather do it later than sooner.
Ed, did you use the Schnorr washers when you re-assembled Ruby? Has anybody used the setup being advertised on PP here?
http://forums.pelicanparts.com/porsc...-cv-bolts.html
Ron, your friend's story is pretty scary. I hope he didn't damage the engine.
I'm planning on a new clutch in the next 12 months. I'd rather do it later than sooner.
Ed, did you use the Schnorr washers when you re-assembled Ruby? Has anybody used the setup being advertised on PP here?
http://forums.pelicanparts.com/porsc...-cv-bolts.html
#5
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I would bet that your clutch disc is broken, and if the CVs are tight, you will soon develop shifting problems in addition to your existing symptoms.
#6
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You can do CV bolts independant of the clutch. The bolts you reference are actualy posted here too-the thread still must be on the front page.
Ironically, I broke down and ordered a set yesterday or the one before. Seems like cheap insurance. I've found a loose bolt twice, and this is on my semi- annual check list. Should be on everyone's.
Ironically, I broke down and ordered a set yesterday or the one before. Seems like cheap insurance. I've found a loose bolt twice, and this is on my semi- annual check list. Should be on everyone's.
#7
I haddah Google dat
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more cheap insurance. Less than $10 per bag of 100
http://www.mcmaster.com/#metric-washers/=8cknvw
hit the belleville link, select "serrated", and find your size.
http://www.mcmaster.com/#metric-washers/=8cknvw
hit the belleville link, select "serrated", and find your size.
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#8
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I think I did notice more noise from the tranny after the clunking began.
#10
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more cheap insurance. Less than $10 per bag of 100
http://www.mcmaster.com/#metric-washers/=8cknvw
hit the belleville link, select "serrated", and find your size.
http://www.mcmaster.com/#metric-washers/=8cknvw
hit the belleville link, select "serrated", and find your size.
#11
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It is a long story that involves in-laws who need transportation and I need to get to the airport. Sometimes three cars aren't enough. Luckily it is as terminal D in an end-spot parked way out of the way.
#12
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I used to drive around for 30-45 minutes to try and find the perfect spot. Several times I had notes left on the car by both friends and strangers. Used to crack up over that. I also used to set off a lot of car alarms in the garages.
#13
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Scott,
I vote for calling AAA and getting a tow home. You will have airport security thinking you are stealing your own car. ha Good luck. Crawling under your car in 100 degree heat at the airport doesn't sound like much fun. AAA was a good investment when I purchased my car. It has already paid for itself with 2 tows in the past 12 months.
Craig
I vote for calling AAA and getting a tow home. You will have airport security thinking you are stealing your own car. ha Good luck. Crawling under your car in 100 degree heat at the airport doesn't sound like much fun. AAA was a good investment when I purchased my car. It has already paid for itself with 2 tows in the past 12 months.
Craig
#15
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Well..... All axle bolts were tight so it appears to be the clutch. Kudos to Pete for diagnosing it based on my goofy explanation.
I went ahead and drove it home and as Pete noted, shift quality is deteriorating.
I guess I need to start planning the drivetrain drop and all the WYAIT stuff like vacuum hoses, fuel lines, etc.
I went ahead and drove it home and as Pete noted, shift quality is deteriorating.
I guess I need to start planning the drivetrain drop and all the WYAIT stuff like vacuum hoses, fuel lines, etc.