Need advice on how to proceed with clutch and possibly flywheel change

[Edes300]

Hello, looking for some advice on my next project.  I have a 2003 996 C2 with 120,000 miles on it.  Original engine suffered IMS bearing failure and new engine was replaced by Porsche in 2008 at 45,000 miles.  At 65,000 miles original clutch was replaced.  The car is in good shape and I'd like to keep it for at least a few more years.  I've done all of the maintenance myself over the years including struts, spark plugs, coil packs etc.

 

Clutch is now staring to slip so I stopped driving it and am contemplating trying to do this myself at home on jack stands.  I don't know what the condition of the flywheel is like and if its the original one or a new one was part of the replacement engine.  Also thinking about replacing the AOS while I'm in there, no idea how old that is.  I wasn't going to buy any parts in advance since I'm not sure what I will need.  Clutch and flywheel prices for LUK and Sacs are all over the place and big price difference between URO AOS and Vaico.

 

Does it make sense to just drop the engine and transmission together, or just drop the transmission?  I would think it would be easier to just drop the tranny.  Any tips/suggestions would be greatly appreciated. 

 

Thanks in advance.

[JFP in PA]

You only need to drop the trans to do this job, but you will need to support the engine during the process.  On a lift, we use a pole jack with a hockey puck on top to do the job, on jack stands you will need a smaller version, and there are aftermarket engine support bars available that will accomplish the same goal.

 

Changing the AOS is an excellent idea, it will never be as accessible as it is when the trans is out.  I would also strongly recommend doing the RMS while you are in there.  You will also need all new fasteners for the clutch and flywheel as the factory are all single use items.

[Edes300]

Thanks you for your advice, do you think I could simply clean the flywheel with a 3M scotch brite pad and reuse it as long as there is no scoring or uneven wear?  My flywheel may have only 80,000 miles when the engine was replaced, I'm not sure.

 

 

[JFP in PA]

Cleaning the flywheel is fine as long as it is not cracked and otherwise OK, and passes the spring back elastomer tests: Tech bulletin on how to test DMF

 

Just do not attempt to resurface it, that will kill the dual mass function and make it worthless.

[Edes300]

So I jacked car up today and took plastic under panels off just to get an overall look and plan things out.  Trying to jack up car on jack stands and measuring under driver side is about 18inches.  There is a slight upward slant between the engine and transmission as my garage is not completely level.  Before I start taking any bolts off, Do you think the car is high enough to clear?  I'm using the harbor frieght scissor transmission jack. I'm also concerned that is its not completely level I may have a very hard time putting transmission back up to the engine in the end.

 

Any advice is greatly appreciated, thanks.

[JFP in PA]

Going to be very tight at that height; while we normally work on a lift, if pressed to do it on jack stands, I would like to see 22-24 inches.  You are also going to need to support the engine while the gear box is out with either a support bar or screw type jack stand with a hockey puck on top to protect the engine case.  I have helped friends do this on stands using what are called Lift bars that lock into the cars lift points and 6 ton stands which can get the car safely up high:

 

 

 

 

Shown here under a 986 Boxster:

 

 

Engine support bar:

 

Screw type jack stand to support engine:

 

 

 

[Edes300]

I can get the car a little higher but if its not completely level my main concern is that I wont be able to get the splines of the transmission to match into the engine when I try to button everything back together.

 

 

[JFP in PA]

I believe the Habor Freight jack you mentioned can tilt somewhat, but I don't know how much as I have never used one.  The engine is also going to be slanted downward slightly when you pull the gear box, so being exactly level is not critical. 

[Edes300]

I finally finished this project but I'm now having an issue with the clutch pedal.  The clutch no longer slips and engages very quickly without issue but the pedal comes back up half way.  No problem changing gears.  I have to put my foot behind the pedal and pull it up to get it all the way back.  After driving for a few minuets it works normally.  I'm concerned there may till be some trapped air in the slave.  I replaced the slave cylinder at the same time and had my son try to help me bleed the system but maybe I need to pressure bleed it.  

 

Very frustrating to think your done and now have more work to do, it always happens.

 

Edited June 12, 2022 by Edes300

[JFP in PA]

Re bleed the slave.

[Edes300]

Happy to report all fixed!

 

Initially I made it worse, I usually do my brake bleeding with the Motive bleeder empty to keep it clean and just watch the reservoir closely.  I did that technique with the slave and the pedal went all the way to the floor.  After more research I realized that the master cylinder takes the fluid for the slave at a different point higher and the Motive bleeder has to have brake fluid in it or you run the risk of introducing more air.  After I used the normal technique everything works perfectly.

 

Thank you for all of your advice.

 

[JFP in PA]

5 minutes ago, Edes300 said:

Happy to report all fixed!

 

Initially I made it worse, I usually do my brake bleeding with the Motive bleeder empty to keep it clean and just watch the reservoir closely.  I did that technique with the slave and the pedal went all the way to the floor.  After more research I realized that the master cylinder takes the fluid for the slave at a different point higher and the Motive bleeder has to have brake fluid in it or you run the risk of introducing more air.  After I used the normal technique everything works perfectly.

 

Thank you for all of your advice.

 

 

I have never understood why people use the Motive unit dry; the one in my shop has seen more individual Porsche's than you can imagine, as well as a lot of other makes, and using it "wet" has never been a problem.