5th Gear almost disappeared?

[70S Targa Guy]

Patient is a 1986 3.2 liter matched to its original 915 transmission. 40,000 miles on engine and tranny with original clutch, pressure plate, etc. I have been driving this setup for over 15 years and yes, I know how to shift. I have recently been experiencing a slight bucking of the car in first gear if I am in traffic with the clutch out and just going inching along at about 5 MPH the car will move forward in a slight bucking motion. I attributed this clutch chatter to a clutch out of adjustment so I took it to a Porsche specialist for a clutch adjustment about 1,000 miles ago. He adjusted clutch but that problem is still there but is really no big deal.

The problem that is a big deal is if I am out driving and running the car at redline between shifts as this car should be driven, the shifts between 1-2-3-4 are fine, no problems. The big problem is shifting from 4th to 5th. I will push the shifter all the way to the right and up and more than half the times it finds third gear instead of 5th. As we all know, this could lead to disasterous consequenses. I am very careful now shifting from 4th to 5th at lower RPM's just in case it goes into 3rd instead of 5th. It just seems to me that 5th gear has almost disappeared.

Also, shifting from 5th to 4th is just as challenging. It seems when I downshift from 5th into 4th where 4th gear used to be it does not find a 4th gear but grinds instead. Maybe 4th gear is very close to reverse now. It is much easier to go from 5th to 2nd instead of 4th gear but again...I cringe with the disasterous consequences that will follow that missed shift. I have never missed a gear yet in all my years of driving this car but as used to this car as I am, I think that missing a gear is quite possible even for me in this car's present state.

My research on this forum indicates my problem is either 1)a worn out clutch and/or PP & throw out bearing or 2)the coupling inside near the rear tunnel (under that black vented cover) need some adjustment. Or 3)maybe its something in the shifter itself, a bushing in the shifter. Anybody have any suggestions as to the best plan of attack in troubleshooting and fixing this problem. The car is not much fun to drive right now. Thanks.

[James Brown]

Sounds like your troubleshooting is spot on, Start with the easy stuff first. coupler, bushings, clutch adjustment. You don't 'loose' 5th gear most of the time it just doesn't line up. At last resort, remove the trans. for repair.

[DW SD]

I had a similar problem with the cup bushing at the base of shifter. It was pretty new ~ 4 years and 8k miles. I'd start there. In my troubleshooting, I started elsewhere and ended up doing more work than necessary.

That is a fifteen minute project (maybe a bit more if have to remove some interior to get to the base of the shifter. When reinstalling the shifter, use a punch or something to line up the mounting holes. It will be frustrating, if you don't.


Doug

[WIL84911]

Might also be a shifter adjustment... if the coupler bushings are fine.

[lateapex911]

I'd bet this has nothing to do with the clutch.
I'd inspect and replace all the shifter and coupler bushings. They are cheap and make a big difference in shifter precision. And they are cheap!
The bucking is unrelated as well, I think. I'd also check trans and engine mounts for slop, and replace as needed. (5 mph crawling in 1st gear is bucking territory for lots of cars, even in perfect condition)

[crustychief]

Where are you driving at redline in 4th?

[James Brown]

I didn't want to ask this!!!!

[70S Targa Guy]

Originally Posted by crustychief

Where are you driving at redline in 4th?

OK, not actually all the way to redline in fourth....I was just eluding to the fact the symptoms are more pronounced when I drive the car at high RPM's. But to answer your question, the road I was cruising on is Route 33 North heading up to the Pocono Mts. in PA.

[sobamaflyer]

You wrote a narrative verbatim for what I experienced a couple weeks ago. If it finishes up like mine you will find your shift coupler bushings in a dozen greasy pieces in the boot under the rear access panel.

Start w/ the $20 Bushing kit and budget a couple hours of easy work, see if that fixes your woes.

The 915 is the worst shifting transmission ever

Good Luck

[Porsche84]

This sounds like shifter alignment/adjustment. After you check and replace the bushings and the sleeve bushing just behind the shifter lever, go through the steps to adjust the shift lever. I always lift up the rubber boot so you can see where the shift lever is in the slot on the top of the housing. You need to be sure that the lever doesn't hit the edge of the shift housing while in gears 1 thru 4. You need to make shre it doesnt touch the top/bottom or sides when in each gear as well as being centered when in neutral. This should make sense as you look at it.

[70S Targa Guy]

Thanks everybody for your responses. From your responses it sure sounds like the bushings are shot. I will be buying the 4 bushing kit from our host and doing the install in 2-3 weeks. I'll post my findings and results when I am able to complete the install. Thanks again.

[dicklague]

Bushings are certainly the first step as everyone has said here. Not a bad job and you will be happy to know about how all this works.

I would consider a Wevo rear coupler later on. I have one and it is well worth the $$. No slop and the will not wear out for a long time.