Second gear problems on the six-speed gearbox

[Costas]

I am hoping this post will serve to collect information on a problem which seems common on 986s 6-speeds.

I recently bought a manual 986S with 62000 Km (38500 miles) on the odometer. It was made in Finland, in April 2003.

Before buying it, I had the local (Athens, Greece) Porsche dealer as well as an independent Porsche service shop (with over 35 years experience exclusively on Porsches) examine the car. They determined it was in excellent condition and it was never crashed. Still, with some money to spare and a desire to start with "as clean a slate" as I could, I had the second shop I mentioned perform extensive work, including:

• New clutch and flywheel (flywheel actually needed replacement with broken springs and blueish wear)
  
• New front engine mount
  
• New clutch pump
  
• Adjustment of shifter linkages
  

I mention these to exclude them as probable causes for the gearbox problem I am having. Note that the problem was present before this "overhaul". By adjusting the linkages and changing the transmission oil I was hoping it would go away.

The issue then is that, relatively rarely, the second gear will pop out or it will grind without having engaged fully. It's as if the collar's teeth do not go all the way into the gear (apologies to the mechanics if I am talking nonsense here - I have a simplistic view of how a gearbox works). This will happen both when changing up and down to second.

Once the gearbox oil is up to temperature the problem becomes even more rare, although it has happened once or twice with a warm car. If I am extra careful that second is pushed in "cleanly" and firmly, the problem goes away. Double-clutching also helps I think, because I don't remember it ever happening if I double-clutch on downshifts.

I have found a number of forum posts on the subject. The conclusions range from "I had the gearbox replaced under warranty" to "there is nothing wrong with it and this is how all G86/20's work". I list the posts, hoping to gather all opinions and information here:

• 2nd gear grinds! - RennTech.org Forums
  
• 986 02 Gearbox problem - 2nd gear grinding - RennTech.org Forums
  
• 986S 02 Gearbox problem - 2nd gear grinding
  
• HELP! Massive transmission failure at 22,000 miles Anyone seen this before
  
• Please help me diagnose a clutch-gearbox problem
  
• second gear problem
  
• effort shifting into second gear - RennTech.org Forums
  
• Clutch Question - RennTech.org Forums
  

The last link is particularly interesting, because it suggests that the problem is inherent to the second gear "double cone synchros":

There is nothing wrong with your transmission. This is a common question asked by owners of the 6 speed. There is something peculiar about the double cone synchros of the 2nd gear

I think that I should keep double-clutching and generally nurturing second gear, rather than opening up the gearbox.

Thank you for any information and advice.

Edited May 4, 2008 by Costas

[Costas]

There is so much on the Internet regarding this problem that I have become tired of reading on it. Posting even more links feels ridiculous at this point, but it may help someone, so here it goes.

The same issue seems to have plagued the 996 as well. My conclusion so far is that due to a design or assembly flaw, the gear will sometimes not engage properly and can pop out. I say a design flaw since I have found at least one case where the gear pops out on a brand new 911 with 500 Km.

If the driver does not know what is going on and tries to force the gear through, or even if one shifts too fast from 1st to 2nd on a cold gearbox, it is easy to wear out the brass (not steel) synchros. Once this happens, any service shop would have to think that the driver has been sloppy and that there was nothing wrong with the car to begin with.

So far I have concluded that: If there is always grinding present when going into second, then the synchros are worn. If there is no grinding when shifting properly, then the rare pop-out or half-engaging is due to this presumed design flaw.

• 2nd gear pop-out issues Click here
  
• New transmission needed on 2003 X50 Porsche refusing to cover under warranty
  
• Second gear pop out issue and aftermarket warranties
  
• 3 to 2 downshift problem
  
• 2nd gear grinding
  
• 2nd gear popped out into neutral
  

[Costas]

So far I have concluded that: If there is always grinding present when going into second, then the synchros are worn. If there is no grinding when shifting properly, then the rare pop-out or half-engaging is due to this presumed design flaw.

Unless I have concluded wrong :-), and what goes on is similar to SpeedYellow's explanation, involving the 996's triple cone synchros, (i.e., although the boxster has double-cone synchros, many drivers still fail to push second all the way in, eventually wearing out the collar's teeth).

[heyjae]

My 2000 S had the same problem. It would be difficult to get into 2nd gear and would occassionally pop out. Initially I thought it was carelessness, but realized that it was occurring even when I was being very consious about gear changes. My dealer replaced the transmission under warranty and it has not been a problem since.