genevagear

I purchased a base model 2018 Cayman in August 2017. It is a manual transmission with about 2700 miles. Around the 400 mile mark I had a grind going into second gear from first gear. I wondered if it was operator error because it was so unexpected. I have been driving manual transmission cars all my life and drive one daily. My previous car, which I still have, has 310K miles, the original transmission, and the original clutch. In the life of that vehicle, I have had a synchro grind twice and I knew exactly what I did wrong because both were error on my part. As I continued to drive the Cayman the grind remained intermittent, always upshifting to second gear from first, and never anything I was doing wrong. Once I got past the break-in point of 2000 miles the grind occurred more often when shifting above 4000 RPM, but it still remained intermittent. I have spent hours researching the problem to try to figure out if I was doing something wrong. I spoke to the dealer I bought the car from and they asked me to bring it in. I was reluctant because I know what it is like to replicate an intermittent problem. I finally had to take the car in because it stalled with an engine fault warning. That engine fault was fixed with an EDM update, and since they had the car I asked them to look into the grind. They couldn’t replicate it and I left the dealership frustrated. I spent about two weeks driving the car for no other reason than to understand how the grinding could be replicated, which is a very frustrating activity with a new car. I finally took it to another dealer and they recommended going on a test drive with the shop foreman. During the test drive I was able to replicate it twice and the foreman did as well.The techs were systematic about investigating the problem. They spent three days disassembling and inspecting. They drained the fluid from the transmission and performed a particulate check, and removed the transmission and clutch assemblies. The oil inspection was negative with no sign of premature wear or metallic particles. They did nothing more than remove the transmission. I did ask for a borescope inspection of the transmission, and they said the synchros looked fine. Inspection of the clutch revealed unusual wear and that is all I was told. They are proceeding with the theory that it was a clutch issue. I am not getting a good logical explanation at the moment and need to have a more thorough discussion with them. They believe the clutch was not fully disengaging. I have hard time believing that is the issue because the grind was only occurring with an upshift into second gear. If the clutch wasn’t fully disengaging it would have affected other gears and the problem would have been worse early in life. They plan on installing a new clutch pack and test driving it. We will see if the problem is solved and will update once I know more.

Phil T

Check these out.......Phil

https://rennlist.com/forums/gt4/9420...nd-update.html

https://rennlist.com/forums/gt4/9258...ear-grind.html

genevagear

Thanks Phil. I am familiar with both those posts and have combed through them in the last few months. With regard to temperature, I didn't have the grind when the engine was cold. The problem always occurred after the engine was at normal operating temperature of about 210-220F. The first grind I had occurred on a hot day in late summer. I acknowledge that engine temperature and gearbox temperature do not correlate well, but engine temperature is all I have. I live in a cold climate and am familiar with difficulties some manual transmissions have at low temperature.

genevagear

To follow-up on the initial post, the transmission was replaced in the vehicle. The mechanic initially investigated the cause by checking the transmission cabling, disassembling the transmission and the clutch. No problems were found with any of the assemblies. The final decision was to remove the transmission and install a new one. I was told the new unit is brand new except for the housing which is reused.Porsche prides itself on quality and admits that there are quality escapes at times with some of them being major assemblies such as the transmission. My gripe with PCNA is that they don’t make it easy on the customer who presents such a problem. It has taken multiple calls, visits to the dealer to get this issue sorted out. This is mostly because the dealer must work out the problem with PCNA technical division. The dealer, mechanics, service advisors have been great, but PCNA customer service has punted a lot of the concerns I have raised instead of addressing them. I have not been happy with PCNA.When you buy a Porsche people notice. Those people then ask why the car is in the garage? Why I am not driving it today? My response and experience so far is not information that would make them buy a Porsche. That part of the problem is lost to the customer service representatives I have been in contact with at PCNA. I don’t think they get it because they are tunnel versioned to the fact that it is just a one customer.Recent GT4 and 718 manual transmission issues give me concern because they indicate that Porsche may be sacrificing quality for cost. The manual transmission is a dying breed and Porsche’s supplier may be increasing cost due to lower volume. To offset cost, changes in the manufacturing and design could be introduced. I am speculating, but I must admit the GT4/718 issue with losing third gear appears to be a consequence of cost cutting, improper weld quality control, inadequate/insufficient testing, and poor design. Manual transmissions aren't new, they should not be having these issues. Best practices and the know-how is there to avoid these problems.

I hope this new unit is reliable and work flawlessly. Driving home I noticed it was notchy. I attribute it to being new and probably needs to be broken in. We will see...

Phil T

Keep us posted on the new tranny...…….Phil

wriggly

genevagear

Here is an update on the new transmission and some general observations of the transmission:1. I give Porsche a lot of credit for the design and operation of the gear shift because it is hard to do with a long shift cable. I like to feel the initial resistance of the synchro engaging the cone before synchro meshes. I don’t get that feel with all the gears. Second, fifth and sixth are too smooth, with very little feel of the synchros. There is better feel shifting into third and fourth because there is that initial resistance before the synchros engage and shifter slides into gear.2. When the engine temperature is below 40F the transmission is tough to shift. The gear shifter just doesn’t want to slide into gear and I really struggle shifting when it is cold, with first to second gear being the toughest. Double clutching doesn’t really help the situation either. You really must be patient and gentle with a cold transmission. The clutch pedal also makes a popping sound when it is pressed in the cold, but it disappears when the cabin warms up.3. I haven’t had a grind shifting first to second with this new transmission. That is the good news, but I will say that I have been gentle with it. There doesn’t appear to be an issue with a fast shift when engine speed is above 4000 RPM.4. The transmission likes to be shifted quickly. Perhaps it is due to the light flywheel. I just find it is easier to shift and match engine speed with a quick shift.

worf928