New tranny & synchro, but 3rd & 4th still sticky.

Need some advice here. Last August I had my transmission rebuilt along with new synchros. However, 4,000 miles later it still gets sticky going from 2nd to 3rd and 3rd to 4th.

It gets stuck about 15% of the time. Is this normal? Here's what going on when it sticks:

As I shift into 3rd, it won't go into 3rd (there isn't any grinding, though). If I hold the gear lever in the same spot and don't force it, 3rd gear will eventually open up and take it. The same holds true with 4th gear.

I appreciate any feedback. Thanks.

Rich

[This message has been edited by 911 (edited 02-02-2001).]

Rich,

Have you taken it back to the shop that did the work and complained? It doen't sound like a normal rebuilt transaxle to me! I would sure take it back before six months passed, for sure!

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Warren Hall
1973 911S Targa

Warren,

Thanks for the advice. I had planned on calling them sometime next week. Believe it or not, this shop is one of most reputable Porsche shops in SoCal. I've had terrific service from them for the past 2 years, but I suppose mistakes can still happen.

Rich
'86 Carrera

I had my 911SC transmission rebuilt 2 years ago. New gears, bearings, syncros, etc. It now shifts perfectly and exhibits none of the problems that pop up on these boards. (don't know if I am lucky or just that everything got dialed in right) I think you should take it back to your mechanic. Hey, we all make mistakes. Let's just hope your mechanic does the right thing. Good Luck!

Bill Carcot
1979 911SC
Diablo Region, P.C.A.

Hey, Rich, what did you do to resolve the shifting problem?

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Warren Hall
1973 911S Targa

Warren,

Actually, I took it to my mechanic and he took it for a test drive. He said that the synchros weren't properly broken in yet. He showed me a better way to shift so the synchros could break in quicker. That seemed to work great.

Thanks for asking.

Rich

Rich: Exactly what did the mechanic say as to how to how to break the synchros in quicker? Am curious as to how a change in shifting could make them break in more quickly.
regards,
jlex.

jlex,

It was more of "how" he shifted that enabled me to break in the synchros better. Shifting out of second, for example, was the same, but going into 3rd he "snapped" the lever in there. Snap is probably not the best word to use, so maybe a "gentle, but more forceful" shift is better.

Ever since he showed me this technique, the synchros have felt a lot better.

Rich

Rich:
I've come to the conclusion that the 915 is extremely sensitive to RPM's and will balk if things aren't turning at just the right speed to suit it. If mine balks, it's usually my fault, since I'm trying to do something I shouldn't (kind of like a transaxle with a conscience). I've wondered, however, how much my synchro work (done about 6000 mi ago)was causing balkiness due to the gears not being "broken in" yet. Will probably find out after another few thousand miles if I can ever get the thing out of the garage (snow now). Take care.
jlex.

My tranny has the same issues before and after the new synchros. I think part of it is me being scared of missing third and going back into first. Funny thing is 1st to 2nd and third to fourth are fine. This makes me think it's just a gate alignment problem or bad aim by the driver. Either way the gearbox seems to be the problem, not the tranny.

BTW, does anyone have any experience with Smart Racing products?
http://www.smart-racing.com/ProdCat/Shifter/Shifter.htm

They have some gadgets that look interesting.
Chuck
83 911 turbo cab (With 915 tranny)

I think it has a LOT to do with bad aim and/or gate alignment. I'm actually planning on readjusting my shiftern linkage in its entirety when I get around to changing my tranny fluid.

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Mark Szabo
1986 911 Targa 3.2
1987 Escort 5-speed 1.9
The Porsche Owners Gallery

Jeez, Chuck, that Fabcar 935-style shifter must be made of Unobtainium!

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Warren Hall
1973 911S Targa

I admit, I'm desperate to improve my shifting. I moved from Phoenix just at the end of summer to Idaho so I've only driven the car 1 to 2 times a month for the past year. Not enough to get a good feel for the 915 tranny.

I think if I could just lock out 1st like they do with the reverse gate I'd be ok. First week I had the car I went back into first instead of third and saw my wallet flash infront of my eyes.

Chuck

gee, that sounds familiar! i've rebuilt hundreds of porsche trannys, and you really have to go out and shift the crap out of them , up, down, repetedly thru whatever gears are hard to get into. pretty firm, somewhat forceful shifting too. you can't give them to the customer until they shift reasonably well. them the customer needs to be instructed that some break-in time is required. some shift ok in 5minutes, some take days or weeks, and occasionally, one gear never shifts well, requiring warranty repair. seems like years ago we never had this problem. have discussed this with many good porsche techs, and haven't shed much light on it. it's not gear oil, GL5 80/90 should work fine. i'm convinced it's a manufacturing tolerance problem. sure would like to figure it out!