Help diagnose these shifting problems - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Boxster with 5 speed manual that is new to me, with no available history. Meaning I have no idea when clutch was last replaced. With car on jack stands, and motor off, the tranny will shift into all gears. With car on jack stands, and motor running, the tranny will shift into all gears. With car on the ground, and motor off, the tranny will shift into all gears. With car on the ground, and motor running, the tranny will only go into 3 and 4th (never tried 5th). It will not shift into 1st, 2nd, or reverse. On the road, with only 3rd and 4th, there is no grinding with those two gears, and when I try to find 2 in a downshift, there is no grinding, just won't go into gear. So I thought it was a shifting linkage problem, EXCEPT that it goes into all gears with motor off. Since it finds all gears with the motor off, while on the ground, I believe motor and/or transmission mounts are okay. With car on the ground and motor running, when I try to shift into 1st, 2nd, or reverse, there is no grinding. Oddly enough however, when I tried to shift into reverse to back out of the garage, the car would go back a few inches almost like it was in gear (which it wasn't though it may have been close). Strange. With car on the ground and motor off, put tranny into reverse, depressed clutch and tried to start. Car would not start, but it would roll backwards a few inches as the starter motor was slowly turning the engine. So, I thought it was a clutch problem. Tried bleeding the clutch, no difference (but allow that my method was not the approved pressurize the system) Now, I am not sure what I have. A bad clutch (though no grinding), or bad linkage (though it finds all gears with motor off), or do the mounts change with the motor running (meaning I discounted that item prematurely?) Obviously, I am confused. Can you help? Thanks, Joe

Geez, can't believe I been fooling around with this for so long. Finally, got around to bleeding the clutch properly. That was an ordeal in itself, but believe I finally got it. Problem is, still can't shift gears when car is running and on the ground. Is there a way to test the slave cylinder to see if it is functioning? I can move the shifter towards each gear, and hear movement in the back, so I believe the shifter cables are trying to go the right places. Still, I'd like to "know" that its not the front motor mount that is keeping the cables from moving adequately to engage the gears. Can I jack up the front of the motor to simulate a new motor mount? Any ideas? Thanks, Joe

I don't know much about Boxster specific transmissions but in general it sounds like the syncromesh mechanism in the transmission is worn out and preventing the gear changes. A transmission rebuild may be required. There is also a known issue that could occur on rare occasions, frequently when a short shifter has been installed that the linkages may have popped out of their restraints and are slipping when more pressure is applied, or broken plastic retainer. Checking involves removing the center console around the shifter back to the armrest. Its fairly easy to do yourself and wise to check the cheap possibilities before getting the Transmission rebuilt or replaced. Maybe someone with specific tranny knowledge can chime in.

I've had the console out recently and the shift linkage looked good at the shifter - which is stock. Good idea though. In my first post, I mentioned not being able to start the car with the car in reverse. That is, with the car in reverse, with the clutch in, when I turned the key to start the engine, the whole car was moved by the starter motor backwards. At that time the car was in a garage with no room to move forward. Today, after bleeding the slave cylinder, I was able to put the car into first, press the clutch in, and turn the key to start the motor. The car did not move from the starter action. The car DID move as it should when I let the clutch out and if I pushed the clutch back in, the car came to rest as it should without rolling. (Reverse also worked with that method which is an improvement, so bleeding the clutch definitely helped.) By the way, the clutch grabbed near the floor on the release. Not near the driver. I think that means there is a lot of clutch material remaining. No? So, I think the slave cylinder does work. And I think the clutch is not worn out. It also pushes me a little more in the direction of the suggested synchros not working properly, but then again, that doesn't really explain not getting into reverse from neutral with the motor running. Hmmmm? How about ya? Got an opinion? Thanks, Joe

could this be a problem with worn out motor or transmission mounts? with the weight on the wheels, it may be throwing off the alignment enough to interfere with the engagement of the gears. just a thought new to the Porsche setup, buthave seen similar problems with cars with mechanical linkages not isolated to the transmission.

If the motor mount was the cause for difficult shifting when the motor is running, wouldn't it also interfere with shifting when the motor is not running? As and additional test, however, I jacked the car up and placed wood blocks under the front engine mount and lowered the car onto the wood blocks, thinking that would take weight off the mount, and still with the motor running, it would not go into gear. With the motor off, it will. That is why I discounted the idea of the motor mount causing this problem.

Has the clutch been replaced? Has the Oil in the transmission been replace with a correct grade /type of oil. (Hypoid 75w/90) If it was me I'd start their. I believe it has nothing at all to do with engine mounts.

What occurs when attempting reverse when running- grinding or balk?

Hi all that helped on this. Problem has finally be fixed when the pressure plate was replaced. To summarize - discovered the problem was that the clutch would not disengage. Confirmed that the clutch release lever was moving when clutch pedal pushed. Already had installed new release bearing, so, we knew that the pressure plate was not doing its job. Sure enough, replacing it fixed problem. Either I can't recognize how much wear to the fingers is too much wear thus the pressure from the release bearing was not sufficient to spring the splines, or there was another problem, i.e weak splines that when pressed didn't release the pressure plate from the clutch disc. Thanks for everyone's input. I know many suggested doing a complete clutch job from the beginning, and that would have worked, but then I wouldn't have learned all that I did chasing dead-ends. It was an education that I'm sure will help at some point in the future. Thanks again, Joe