Can"t downshift to 4th

[nikita76]

I've got my targa on the road for the spring/summer and as of late (the last couple of days) having a hard time downshifting from 5th to 4th. The stick shift feels "blocked" out or forced around a curved piece of metal to the 2nd position. Any ideas?
Thanks,
Nikita

[Slider79SC]

I have the same situation with my gearbox. I will be interested to see what the tranny gods have to say....

[kach22i]

I am the furthest thing from an expert on this, as having just gotten my first Porsche Tatto (grease on my hands) recently. However I must ask, when was the last time you changed or adjusted your shift coupler?

[Early_S_Man]

Remove trapezoidal cover over shift coupler in the tunnel ...

1. Check for loose set screw and/or pinch bolt ...

2. Check for crumbling, deteriorated plastic bushings inside coupler ... signs would be a pile of crumbled plastic bits below coupler on tunnel floor ...

[Slider79SC]

I'm not trying to hi-jack Nikita's thread, just giving my answer to these questions to keep you all working on it.

Everything is new, bushings, coupler, coupler bolt, shifter.

[Early_S_Man]

Slider,

What exactly do you mean by 'new' shifter ??? A new-to-you used shifter from eBay, salvage/recycler, etc.?

Did you ... if a used shifter ... disassemble, clean thoroughly, then 'shim' out all internal 'play' in the shifter, and lubricate with moly grease ... before installing in the car??? Is it a later model wityh adjustable tension [Allen] screw and locknut on the forward portion of the shifter housing ... or does it have two rollpins, i.e., an early production 915 shifter?

[kach22i]

Early_S_Man, you are coming up on 10,000 post. Will there be a party?

I will be reading this post intently- good questions.

[Slider79SC]

HI Warren,

I have tried a new Wevo shifter, a new rennshift shifter, a rebuilt shifter with the sien system and I always had the 5th to 4th downshift issue that Nikita described.

All budhings are new and I have a Stomski coupler in it. Strange huh????

I hope you guys can give Nikita and I some guidence as to where to start looking for this issue...

[nikita76]

I'm at work right now, and will be removing the "plate" for coupling access tonight when I get home. I've had the car 3yrs and have not replaced/repaired that coupling or those bushings before. I'll let you know. Thanks for the lightning quick response guys!!
Nikita

[nikita76]

O.K., I pulled back the carpet, removed the panel and found a urethane bushing broken into 2 pieces. I suspect this is the culprit for my dilemia, but I can't seem to locate it's origin. It looks like a small spool of thread. The coupler bushings are intact. Where did this thing come from?!!!
Thanks for any input!
Nikita

[Early_S_Man]

Nikita,

Is the 'spool' approximately 1" inside diameter? If so, then it may be the shift rod bushing that normally resides behind and below the shifter ... #56 in the following diagram.

Another possibility is that it may be an old ball cup bushing ... left to roll down the tunnel after a previous replacement job on #57.

[Hugh R]

Probably part 56 or 57 from above. Buy the rebuild kit from our sponsor its like $20 or $30 bucks, for the bushings and the rear part no 61 rubber. Pressing out the rear rubber part no. 61 is easy with a large vise and under and over sized sockets to push and receive the pin. Its all well worth it. There's a technical bulletin on this site that does a better job of describing the readjustment procedure than the description in 101 projects.

[scottb]

Your car is 20+ years old. It's time to replace all of the bushings. So, while you're in there, do the shift coupler (either replace altogether or just the bushings), and bushings 56 and 57 in the diagram above. You'll be amazed at the improvement.

[nikita76]

Hey guys! Thanks for everybody's help! You're not going to believe this but...the allen bolt on my coupler was loose!! Yup, thats it! But I am going to replace the coupler and bushings soon with a short shift kit upgrade.
Thanks again!
Nikita

[Groesbeck Hurricane]

One last question: Are yall double clutching the downshift?

[scottb]

Originally posted by nikita76
I am going to replace the coupler and bushings soon with a short shift kit upgrade.

Go with the factory short shift kit. It's a bit more expensive, but worth the extra $$. Also, if I'm recalling correctly, the kit did not come with any bushings, so you'll have to order them separately. If I were you, since you'll be in there working anyway, I'd replace the coupler (or coupler bushings) at the same time.

Have fun!

[Early_S_Man]

Nikita,

I am going to recommend against a short-shift kit of ANY kind! It does shorten the throw, but at the expense of higher effort, and less fine-control of the shifting process by hand pressure ... because there is less feedback to your hand and arm about the synchro engagement forces which vary with the wear and conditions of all of the tiny parts of the Porsche-patent synchro mechanism!!! Depending on what you motivation is, i.e., racing, where every second counds and a bit of extra wear and tear on the synchro may be tolerable if the transaxle gets torn down at the end of the season ... or just the 'cool' and bragging factor ... makes a lot of difference in the cost/benefit tradoff analysis ...

A normal, street-driven 911 doesn't need the short-shift kit, and it has been posted by several pros that rebuild the transaxles -- that extra wear is caused by the short-shift kits! Pausing between shifts for the smoothest possible shift is the key to long, happy 915 transaxle life, and installing a short-shift kit is contrary to attempting to obtain and enjoy good health of your 915!

[nikita76]

Thanks early s man!! That makes alot of sense!!
Nikita

[ASD]

Originally posted by Groesbeck Hurricane
One last question: Are yall double clutching the downshift?

ALL shifts? I have never double clutched all shifts, just curious as to who does that and why.

[nikita76]

Hey guys! Great news! The steering wheel was nice and steady over the100+ miles I did today! I experienced the usual wheel shake when going over bumps but I'm sure that will disappear when I upgrade to the elephant racing bushings. I know what many of you are saying...(why spend that kind of money on a car you drive for the spring/summer in New York?!) I would rather take twice as long to pay for something knowing that it's done right and complete than settling. Do it once, do it right and your done! I'm re-balancing the rears in the morning! Hope this helps!
Nikita