sporqster

hello all,

Last weekend, my wife and I went to our first ever DE event at Roebling Rd, GA. Had a blast... until my wife's '79 911SC started refusing to go into 2nd or 4th gear.

We've only had this car a few months, and it has always been a long, slow throw from 1st to second when compared to that of our WRX or her old Civic. Not familiar with Porsches or the 915 tranny, I figured this was normal. Also, can't shift into 1st unless it's pretty much stopped. But the latest problem has been that it simply will NOT go into 2nd or 4th... can't even manage to grind 2nd or 4th. you just move the shifter to where 2nd or 4th ought to be, let out the clutch and, well nothing. it's like it's in neutral.

I've been told the synchros are gone, I'll need to rebuild the tranny... I thought that typically when the synchros go, the transmission shifts, it just grinds like hell. There hasn't really been much grinding on this tranny - so is that the right diagnosis? Are these symptoms typical of another problem?

Anyone want to direct me to a good source other than my handy Haynes manual for attempting to fix whatever is wrong with this thing?

I have an old friend (who unfortunately lives about 11 hours away) who has recently done a tranny rebuild on a '78 911SC (I think that's the right year), and I can bum some tools from, and I have a basic set of tools in the garage, such that I think I could drop the engine/tranny myself if I had to, but as this is a daily driver and the garage is already 1/2 full with a long term project car, I can't afford to make this Porsche into a major time consuming ordeal... However, it would be nice if the ol' 911 could row through the gears like the Subie does... 915 upgrades, adjustments, other advice?

HELP PLEASE!!!

Peter Zimmermann

2/4 problem sounds like linkage. Open the cover on the top of the center tunnel, below the back seats under the carpet, and look for something that might have slipped. 2nd & 4th are not connected internally (1st & 2nd share a shift sleeve, and 3rd & 4th share one), so it sounds like an external issue.
Pete

sporqster

I did look at the bushing under the plate in the middle of the back floorboard- that bushing appears to be fine. Is there anything else I should look at?

Peter Zimmermann

Yes, check to see if the bottom few inches of your shift lever, where it comes up from the console, is vertical. It will probably be leaning toward the rear of the car. If it is, look into the coupler area (at the rear of the tunnel), you will see where the splined shaft of the coupler is attached to the tunnel shift rod. This clamp joint can slip, which can cause your shifting trouble. If it has slipped you will see a mark/discoloration on the splined shaft where the connection moved. Use a light, it gets dark in there!
Pete

sporqster

The shifter was leaning a little back, so I adjusted this even to the point that it was leaning a little forward... still no way was it going into 2nd or 4th. I put the back end up on jack stands and let out the clutch in 2nd, and the wheels spin- as long has I physically hold the shifter down in the 2nd position. as soon as I release the shifter ****, it goes into neutral. Getting a bad feeling about this...

Peter Zimmermann

Hmmmm... Very unusual. If you're absolutely sure about your lever being vertical I don't know what else to suggest. Your shaft that I need to see is covered by the rubber boot in your pic, so I can't comment on that. I assume that your adjustment did not restore 4th to working condition? Do you have a Target brand, or similar, short shifter?
Pete

sporqster

I believe the shifter is stock, since posting here I have removed the entire shifter linkage from the tranny shaft in an attempt to put it in gear by hand. I can farily easily reach all the other gears other than 2nd/4th, and can get the rotors to spin in 2nd/4th by applying pressure to the shaft 'towards' that gear, but it won't stay in the gear, and I can't hold it in that gear with any pressure on the tranny (letting out the clutch slowly with the brake applied).

I think I have found a reasonable deal on a rebuilt '74 911 tranny. Will the speedo work right on this tranny? I have the electronic type I beleive. It would be more cost/time effective to swap the tranny, get the car back on the road, since it's my wife's daily driver, then rebuild this one at my leisure.

Peter Zimmermann

Way too many complications involved with a swap like the one that you're considering, my advice is to not attempt it. Find the problem with yours and have it fixed. By the way, you haven't mentioned reverse, does it still work?
Pete

sporqster

yes reverse works fine, and in further investigating, I finally found a 17mm hex key to get the tranny drain plug off and to my horror, there were to hunks of metal about the size of tic-tacs stuck to it. That can't be good.....

Now I'm shopping for a replacement tranny. I would try fixing the problem myself, but with this car a daily driver, it would be tragic to "fix" the problem, replace the tranny, only to find that I made some n00b mistake on the rebuild and handgrenaded the tranny in a week, possibly leaving the wife stranded (her car).

bourgeois911

I think Vertex has an exchange for around $1500, might be the quick way out.

jet911

Like Pete says, fix your tranny, don't exchange it. With chucks of metal, sounds like you are in for a rebuild. Are you going to drop the engine/tranny yourself? If so and if there are no reputable shops or tranny rebuilders in your area, I would send the tranny to Gary Fairbanks to have it rebuilt. From what I have read/heard, he is one of the best with a very quick turnaround (2 days). If you do a search, you should be able to find his number, or if you are a PCA member, he advertises in Panorama as well as in Excellence.

Good Luck!

Regards,
Jim
'86 Coupe

fatboyq

how much will the rebuilt cost compared to the exchange unit?

jet911

If you drop the engine/tranny yourself, the rebuild should be about the same as an exchange. The major difference is during a rebuild you can dictate what to replace while you'r in there....

Slotcar

Have any of you guys used Moto-Meister? I don't know anything about them, other than viewing their website. I am not affilated with them in any way, nor could I say anything about their quality of work. Just passing along the web address....

http://www.motormeister.com/suz/trans/clutch_trans.htm

DJF1

If you go the rebuilt way for sure take advantage of it and do the gearing as well. Your butt dyno will thank you. One more thing. I had the same thing that happened on my g50/20 993 gearbox. While its much newer it did exactly the same thing I could not find the lower gears 2,4,6. Finally it came about, but it would do that under certain circumstances. Well it was an internal part that sits between the forks in the tranny. Once that was replaced no issues again. BTW i got some metal chards as well, my spider gears were toast...