*HELP* Problems after transmission fluid change.

[EricGregory]

Greetings everyone.  I've got a really weird problem going on at the moment.  So, I put my car up on my jack stands and did a transmission fluid and front differential fluid change with Porsche OEM 75w-90 fluid.  

 

After buttoning up everything and making sure everything was tight and not leaking, I took the car for a test drive.  I noticed first of all, that my clutch wouldn't quite return properly when I started up the car.  I checked to make sure the floor mat wasn't causing any problems, the clutch pedal popped right back up, so I assume it was the mat.

 

After getting the car out of the garage, the clutch was returning properly, until I made it to 3rd gear.  At that point, the clutch felt, the best way I can describe it is "sluggish."  Then, it felt like the clutch was slipping horribly.  Trying to accelerate in any gear was was nearly impossible.  Incidentally, I could start the car on a hill without any problems (in first, obviously).  

 

I finally made it home, put the car in my garage and will crawl around under it in the morning.  The fluid change was a simple task so I don't know what could have gone wrong.  I filled it until it dripped out of the fill hole, so I definitely didn't overfill (yes, I used the forward fill hole, not the one by the axles) :-)  Everything was working perfectly prior to the fluid change.

 

 

Anyway, has anyone ever experienced anything like this after changing transmission fluid?  What could I have done wrong or screwed up?  

 

 

PS:  The car is a 2008 Carrera 4S

[JFP in PA]

Changing the gear box and/or diff fluids should not have any impact on the clutch operation.  Are you sure that you used the correct fill opening, some 996/997 actually have two plugs.

 

 

http://www.renntech.org/forums/topic/48480-9972-transaxle-oil-and-capacity/

 

http://www.renntech.org/forums/tutorials/article/64-manual-transmission-oil-change-instructions/

[EricGregory]

Thanks for getting back to me. I used the fill hole in the forward part of the transmission.

It's strange, sometimes the clutch pedal doesn't want to return and even when it does it feels like the clutch is still partially engaged. Basically pressing the accelerator increases RPM but the speed of the car doesn't increase.

I've done trans fluid changes on plenty of cars but never had this problem.

[JFP in PA]

Thanks for getting back to me. I used the fill hole in the forward part of the transmission.

It's strange, sometimes the clutch pedal doesn't want to return and even when it does it feels like the clutch is still partially engaged. Basically pressing the accelerator increases RPM but the speed of the car doesn't increase.

I've done trans fluid changes on plenty of cars but never had this problem.

 

If you used the forward plug, you have probably overfilled the trans and have gotten oil on the clutch.  You are supposed to add fluid through the lower plug to the right, and should have used around 3L of fluid.

 

Try removing the lower plug to the right in the photo and let the excess fluid drain off.  You may just get lucky.

[EricGregory]

Yep. I used the lower hole and filled until it seeped out. Either way I'll drain a bit and hope it helps

Edited February 28, 2016 by EricGregory

[JFP in PA]

Yep. I used the lower hole and filled until it seeped out. Either way I'll drain a bit and hope it helps

 

If you used the lower fill plug, the trans cannot be over filled, and the gear oil is not the source of your other problem.

[EricGregory]

I drained a bit.  There was a slight improvement, albeit *very* slight.  I think something else has gone wrong.  It just makes zero sense that it worked fine before I changed the fluid, now it's pretty well useless [as a car] :-p  I guess I have to find a garage to check it out...  

 

Thanks :-)

[Ahsai]

Is it possible some clutch hydraulc lines were pinched when you jacked up the car? How is the brake fluid level?

[EricGregory]

That's one of the other things that came to mind.  Initial inspection of the hydraulic line to the clutch turned up nothing amiss.  

 

One of the other bits of work I did was to replace the left front outer CV boot so I had an axle off the car as well, but I can't see any way that would be related to the clutch issues.  I'm stumped.

[jchapura]

My two cents probably aren't worth two cents but I think this might be just coincidence. Or, a very subtle cause and effect.

 

It sounds like the pressure plate is no good.

 

Would love to have you report back when you do learn the cause.

 

For what it's worth, I did this same fluid changeout a few months ago on my garage floor and did not experience what you have. I can understand your frustration.

[EricGregory]

I had the car trailered to an indie garage that works on P-cars.  Long story short, the clutch plate was bad.  The reason blew my mind...  Basically, the plate had become misaligned and had worn unevenly.  When the garage popped off the transmission to get to the clutch they said a bunch of corn fell out of it.  Corn, yes, corn.  Mice had evidently been storing their foodstuffs in the transmission.  The crazy thing is that the car is in fact driven several times per week.

 

So, 2200 bucks and a new clutch later, the car is running fine.  I think I need to get an owl for our garage.  Our cats are entirely too lazy.

 

Anyway, that's one problem solved.  

[Ahsai]

Mystery solved :) On 996s, there's an opening at the top of the transmission housing for flywheel inspection. Maybe 997s are the same.

[EricGregory]

Yeah, they mentioned a vent hole that shouldn't be covered.  Seems like a bit of a design liability to me, but I digress.  

[JFP in PA]

Mystery solved :) On 996s, there's an opening at the top of the transmission housing for flywheel inspection. Maybe 997s are the same.

 

They are the same.

 

Vermin storing lunch has got to be a new one to add to the books.

[Ahsai]

 

Mystery solved :) On 996s, there's an opening at the top of the transmission housing for flywheel inspection. Maybe 997s are the same.

 

They are the same.

 

Vermin storing lunch has got to be a new one to add to the books.

 

This opening, right?

 

[JFP in PA]

 

 

Mystery solved :) On 996s, there's an opening at the top of the transmission housing for flywheel inspection. Maybe 997s are the same.

 

They are the same.

 

Vermin storing lunch has got to be a new one to add to the books.

 

This opening, right?

 

IMG_4173 (Medium).JPG

 

 

Yup, here's a 997 gearbox:

 

[Ahsai]

Interesting to know. Thanks!

[JFP in PA]

I always thought that placement for an access/vent was strange, some other makes use two or three horizontal slits that a mouse would have a hard time getting through.  On the Boxsters, there are a couple of smaller openings near the very top of the bell housing, plus two small ones on the very bottom, none of which are that sized, but I would guess a determined mouse could still get in there.  God knows they get everywhere else in these cars when they are in storage.

[Ahsai]

Yeah, quite a strange design. I'm more worried about water intrusion when using a garden hose to wash the undercarriage.