[Cloud9...68]

This hasn't been discussed in awhile, but I've been having trouble with the "View New Posts" button, so I want to make sure I haven't missed anything. The last time this was discussed, the buzz that comes from installing an aftermarket shift knob appeared to be incurable. Many people, including me, have stuffed all manner of vibration-absorbing material between the knob and the shaft, all to no avail. Several months ago, somebody was planning to replace the linkage assembly, so I was wondering if that was ever done, and whether it helped.

I'm at the point where I'm ready to go back to the fugly original knob, which I have (although whatever emblem is supposed to fit on top of the knob is missing on mine; the previous owner had installed a new GT3 knob before I bought it - beautiful, but it makes a huge, and hugely annoying, racket). He gave me the old one as a spare. Thanks.

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[Johannvb]

Hey Cloud, this is the topic you were looking for http://www.968forums.com/index.php?showtop...60&start=60 . It never got updated. I am also waiting for feedback on it because I also have a slight buzz with my OEM knob.

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[Cloud9...68]

Thanks, Johann, I remember that thread well. I just replied to it. Hopefully we can find a solution to this problem soon.

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[FraMac]

I did the simple cure with mine and put the old shift back on (sorry - doesn't help you much I know). I fitted a 993 shifter which buzzed and rattled and drove me bonkers eventually.



I think the weight of the original shift reduces the amount it vibrates.



Good luck.



Fraser.

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[Cloud9...68]

Sigh, yes, I'm afraid you've hit on the only known solution. I'm still going to work some more with the plumbers tape I've got the shaft wrapped with. I'm trying to apply the right thickness, such that it provides a snug fit all down the length of the shaft, without causing it to all bunch up at the bottom of the shaft after I force the shift knob on.

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[flash]

i'll play with dan's knob (can i say that on the internet?) on the 6th when he is down here - i just may have a solution

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[ds968]

lol, as long as you don't " polish " it, i think it'll be ok to test a few solutions for the vibration problem. though after seeing what your lady neighbors look like, it could be wothwhile seeking their technical help with the knob also.. <img src="/forum/images/smilies/968/wink.gif" class="smilie" alt="" />

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[Fox944]

Put the old knob back on, get a brushed aluminum insert to tart it up a bit. <img src="/forum/images/smilies/968/cool.gif" class="smilie" alt="" />

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[PorscheDude]

I just lives with the buzz.

My favorite solution was to keep the RPM's up or crank up the tunes.

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[flash]

well, another failed attempt at a fix



dan came down and we tried adding mass to the rear of the linkage - while it all but silenced it in neutral, it had no benefit in gear - there wasn't room to add the mass up front - the idea was sound, but the implementation was incomplete



the buzz originates at the transaxle and travels up the linkage, through the shifter, to the knob



the solution is going to be 1 of 4 things:



1. add mass to the shifter, but in a fashion that is damped via something like the oem rubber boots - it needs to have the ability to isolate and free float - hard mounting makes it worse



2. add a LOT of mass to the linkage, with a few shaft collars clamped along the way to break up the standing wave - this may add wear to the bushings at the ends though, and may also add resistance in shifting movement



3. turn up the stereo



4. go back to the oem knob

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[TonyBray]

5. Some genius (Flash) figure out how to drop the linkage all together and design a cable-shift arrangement. Vibrations from the rear won't travel along the cable and we can save more weight <img src="/forum/images/smilies/968/wink.gif" class="smilie" alt="" />



Happy Friday!

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[flash]

lol - they have such a gizmo already - it's called a tiptronic

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[AJG]

If someone can supply drawings of any small bushings they need which can normally only be supplied as part of an assembly, then get in touch with me. Plastics such as Acetal(in black of course!) cost peanuts and there is always some lying around my material store area at my machine shop business. While we're at it, making the odd part out of titanium is easy also, expensive material...yes, but when talking small diameters its still relatively cheap. No charge to make anything (do I sound like a Scotsman? There must be something wrong with me!), just cover postage and material cost if it mounts up. Also you may have to wait till I can fit it in my schedule. Deal?



Andy

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[AJG]

Just noticed RS barns has a ready solution Stateside for short shift vibe problems caused by worn plastic bushings. Looks very nice as well, lovely little machined chamfered edges all round. Nice bit of work, and at a reasonable price to boot! Offer is still there for bushes etc from myself. PS it is advisable to measure mating shaft and hole accurately to determine bush sizes , no point in measuring a worn bush!



Andy

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[ds968]

I can' t speak for any other aftermarket shifter knobs, but for those of you who have the Porsche 996 aluminum and carbon fiber shifter as I do, I just found the solution ( by mistake ) : leave the little base screw untightnened . ! Any contact it makes with whatever is inside the chamber ( rubber, felt strips, etc..does not matter what it is ) is still enough to cause that buzz. If you have sufficient material like velcro, or rubber, or felt, and so on, provided it's stuffed in there really tightly, the knob will not slip off the shifter; you do have to put enough material in to have to apply significant force when pushing the knob down. ( use soapy water over the material make that sliding process easier, and once it dries up, it'll stay solidly in place for years to come.. Just don't tighten the screw unless you like that 2400 to 2800 rpm buzz..

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[Cloud9...68]

I have a 996 GT3 shift knob (all aluminum), and leaving the base screw untightened, or completely off, sadly has no impact on the accursed racket <img src="/forum/images/smilies/968/angry.png" class="smilie" alt="" /> .

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[ds968]

Damn, sorry to hear that.. And who knows, maybe my luck is short lived and it could start the buzz again, but so far so good

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[flash]

lol - live to buzz again. cool. i say that after every hangover.

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[Cloud9...68]

I going to go back to the OEM one, even though I don't care for its looks. It's not so much that I think the shape is ugly per se (a little dull maybe), but mine is just kind of tired looking, with several scuffs all over it, and I don't like how it looks in light gray. But the car is primarily going to be used on the track, and the OEM one's shape is more conducive to fast shifts than my GT3 shifter. I do love the look of the GT3 knob, and its quality is superb, as it shows next to no wear even though it's been in the car about six years.

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[flash]

hey - that will give you the opportunity to run the short shift kit



shameless plug

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