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1990 stick shift is very sloppy: solutions?

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Old 10-12-2017, 10:51 PM
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merchauser
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Default 1990 stick shift is very sloppy: solutions?

My shifter is so sloppy, it really inhibits the feel of driving.

wondering if just replacing with stock bushings is the way to go, or a custom application.

also, would like to know if the biggest culprit is in the rear coupler, or with the shifter cup bush?

hoping to hear from others that have encountered this issue and what you have done
Old 10-13-2017, 08:18 AM
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The Forgotten On
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Replacing the bushings front and rear will help a lot with feel as they tend to degrade over time.

However, the 928 transmission isn't one of Porsche's best efforts and is the automotive equivalent of stirring a bowl of pudding. Smooth, but vague.
Old 10-13-2017, 11:22 AM
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merchauser
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kinda sounds like even with brand new stuff, out the wrapper, its still not that great??
Old 10-13-2017, 12:18 PM
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docmirror
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Start by refreshing the bushings. They are a wear item, and they do wear. Once that's done, inspect the pivot in the shifter stick area for slop.

I find the GT trans a fine unit. Have never had a a problem with it. I had it on the track a couple times, and shifting was good, ratios where where I wanted them, and the PSD operated as advertised.
Old 10-13-2017, 12:38 PM
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davek9
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Is there any "spring" action, right to left?
If not it could be the spring inside the trans, even if sloppy you should feel the spring.

Take the boot off, and observe the action, there is a mounting pivot (top) and the selector to trans (bottom), if the top one moves front to rear the cup bushing is shot at the front of the TT, if slop is side to side its the rear at the trans coupling (or both). No spring action the trans needs to come out.
Both Cup and bushing can be done on jack stands and or a lift

Dave K
Old 10-13-2017, 12:45 PM
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vanster
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If he has one for sale, buy a Hans Shifter kit. I have one in my 86.5 and it's really slick. Not cheap but it will change the feel of the car.
Old 10-13-2017, 01:12 PM
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merchauser
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I am going to get under the car today and look at the rear bushes

of the oem, delrin, and bronze, is there a consensus of what is best. I have read more than a few posts about bronze transmitting too much vibration??

I certainly have spring action, so, thankfully, no worries there.

most of the free play is side to side.

vanstar, not familiar with the hans shifter, can you expand on that?
Old 10-13-2017, 02:09 PM
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merchauser
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UPDATE: no question that the rear coupler bushes are shot. I had a slight rattle at the rear of the car and now I know what it was; the rod is just bouncing around.

now, what is the "best" recommendation for bushings

also, I did not pull back the boot, but it feels like a thin dried out piece of leather. can this be salvaged or should I just order a new one?
Old 10-13-2017, 03:46 PM
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docmirror
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Once you renew the bushings, it will feel a world different. Might look at the front too.

The boot or 'gator' is avail on ebay and other places. Might as well just get a new one and put it on.
Old 10-13-2017, 05:15 PM
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merchauser
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agreed docmirror

I see there are polyurethane, delvin, and bronze bushings

can anyone weight in on pros and cons or recommend which one might be best to go with?
Old 10-13-2017, 06:08 PM
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docmirror
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Delrin is my vote. It's a sacrificial part in a socket and delrin is pretty robust without being costly.
Old 10-13-2017, 07:45 PM
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Originally Posted by docmirror
Once you renew the bushings, it will feel a world different. Might look at the front too.
This!

My front bushing disintegrated at the track and it was slop city, simply horrible.

I replaced it with a metal one from 928 Motorsports, and it's one of the best mods, period. Shifting is much better versus a fresh, standard bushing.

The only downside is that it's a very tricky install, and the engine was out at the time, but well worth the effort.
Old 10-13-2017, 08:14 PM
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SwayBar

don't mind the difficult install, i'm saying that now, but does the motorsports metal cup transfer any noise or untoward vibration?

does anyone make a cup with delrin?
Old 10-13-2017, 10:48 PM
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Originally Posted by merchauser
SwayBar

don't mind the difficult install, i'm saying that now, but does the motorsports metal cup transfer any noise or untoward vibration?
No. It is truly a nice piece of hardware.

I was never fond of the 928 shifter, and was quite despondant with the entire car when the shifter totally crapped out while at the track. Only later did I discover that the front cup's plastic bushing had chipped out.

That metal shifter cup is a total game changer for me since for the first time, it feels like the 928 has a competent shifter/gearbox in it, and I've been driving a 5-speed S4 and GT for 15 years now.
Old 10-14-2017, 12:47 AM
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It depends how long the bushings at the rear have been totally gone, but there could be some wear on the coupler body from the through shaft thrashing around. Check the coupler body carefully, and the through rod for damage. They're probably OK, but do those checks before replacing just the bushes. My vote is to go with the delrin as doc suggested, to get rid of the slight play the standard ones have. It's an individual preference, but some prefer the standard ones to allow the designed play, to prevent rattle being transmitted to the gearbox ... I've driven many cars without such play between the shifter and gearbox, so I don't see why a Porsche box should be any different.

Try a standard bush in the front now, which will be easier than any alternative (and cheap), and then see if you want to do anything further after that, once front and rear are free of slop.

It'll feel like a totally different gearbox once you get the above done.


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