993 rear main seal replacement

[jhg41977]

I am looking at a 96 993 C4S that needs a rear main seal and cluctch. Im pretty capable and considering doing this myself to save some cash. I searched this forum for a thread, couldnt find one. It seems like this forum only goes back a short time (4 pages) are there archived pages I can access?

A few specific questions.
1) Can the rms be replaced while the engine is in the car or will i need to (or will it be easier) drop the engine?

2) Am I a dolt for attempting this? I have worked on many cars but never a Porsche, so I am not sure exactly what I am getting myself into. I am confident that I can do it, its more a question of time.

3) Will I require an 'special' tools? My tool chest is decently stocked, but are there any Porsche specific tools I will need to buy?

4) Since I will have the car apart anyway, any thoughts on additional work? Currently the car has 63k on it. 60k service was completed.

Thanks!

[Carrerax]

Originally Posted by jhg41977

I am looking at a 96 993 C4S that needs a rear main seal and cluctch. Im pretty capable and considering doing this myself to save some cash. I searched this forum for a thread, couldnt find one. It seems like this forum only goes back a short time (4 pages) are there archived pages I can access?

A few specific questions.
1) Can the rms be replaced while the engine is in the car or will i need to (or will it be easier) drop the engine?

2) Am I a dolt for attempting this? I have worked on many cars but never a Porsche, so I am not sure exactly what I am getting myself into. I am confident that I can do it, its more a question of time.

3) Will I require an 'special' tools? My tool chest is decently stocked, but are there any Porsche specific tools I will need to buy?

4) Since I will have the car apart anyway, any thoughts on additional work? Currently the car has 63k on it. 60k service was completed.

Thanks!

#1, It can be done but you still need to drop the trans. Either way it isnt a simple job. I would just drop the engine and trans the first time. The TOB can be a pain your first time.
#2, No and it will take about 8 hours total.
#3, You should be fine. You will just need a decent set of different Torx sockets.
#4, Clutch and RS flywheel would be a nice upgrade. Good time to do plugs since the #6 top plug is a bear with the engine in the car.
You may want to go to www.rennlist dot com and look in the 993 section. That is the very best place to talk about 993's. Then buy your parts here

[jhg41977]

Already priced the RS flywheel through Pelican. I have the torx sockets from the first two engines I parted out a few years back, so it sounds like Im good for tools. Thanks for the input.

[Carrerax]

Make sure you have the correct torx for the FW and PP bolts. I think some of them are 12 point torx if I remember correctly. What sucks is I just did this to my 993 2 weekends ago and cant remember. Also, make sure to get ALL the parts you need for the RS conversion. There are several little things like the TOB slider shaft thing, bearings for the TOB arm shaft etc. You may also want to get a PS belt but they almost never fail.

[jhg41977]

Good to know. Ill call Pelican when I order (assuming we purchase the car) and make sure I don't forget anything. I have the torx required for earlier engines. Not positive its the same. I read somewhere about upgrading the valve covers will help reduce leaks, something about oem are plastic?

[Carrerax]

OEM are plastic. Many people go with aftermarket alum if the plastic ones are warped.

[jhg41977]

Thanks for the help! I talked with the tech who did the ppi on the car and he said the seal is weeping. Do these kind of go along weeping forever or do they suddenly let go? Im considering driving it home, almost 800 miles.

[earossi]

So, I have a few suggestions and clarifications.

First off, I am not certain that it is Torx sockets that are used on the 993. The sockets are sold as "triple square" or "cheesehead" sockets. Snap-On lists them as Triple Square. I am guessing that Torx sockets have a different number of splines than do the sockets I have suggested.

You will need the triple squares for the clutch plate assembly and the flywheel. And, from past experience, my advice is to buy the best ones you can afford. The flywheel bolts are shallow and if you round off the socket because it is soft, it may damage the bolt forcing you to have to grind it off. I have Snap-ons, and they are a nice tight fit in the bolts.

At 60k miles, it sounds like you have a number of weepers and or leaks, so pulling the engine is really the easiest way to change out all the gaskets.

I will disagree with the prior poster on the plastic valve covers. Actually, the fact that they are plastic assures that they will warp. But, again, since they are plastic, they will flatten out when bolted up to the heads. They were designed that way. Conversely, if you go back with aluminum covers, they are flat going on, but with age and temperature cycling of the engine, they will warp and probably leak sooner than the plastic ones. Porsche did not fit plastic covers to shave cost out of the motor.......there was a more specific reason. For me, the only logic to replacing plastic with alumuminum covers is for "look" of the metal covers.

To replace the RMS, you will need to pull the flywheel. If the car is original, that flywheel is the dual mass flywheel, which at 60k miles is close to retirement age. One of the nicest performance upgrades for the 993 is to go back in with a lightweight flywheel and the RS clutch package. You will find that the motor will rev faster and you will never have to worry about the degradation of the rubber center core of the flywheel since the LWF eliminates that item. The only downside to the LWF is that you will get more transmission of transmission noise into the cabin. I don't believe I've ever heard anyone say that the added noise is objectionable, but you will hear a little more noise. Our host has the clutch and flywheel kit as a package for about $2k.

Other than the triplesquare sockets mentioned above, you will not need any additional Porsche specific tools. Replacing the RMS is straight forward and you can find some really nice writeups using the Search function either on this or the Rennlist BBS.

While the motor is out, I would agree that you should replace spark plug wires. Doing it with the motor in the car is a horrendous task (ask me why I know).

In addition to replacing the wires with the motor out, replace all the cover gasketing that has the slightest weep present.

Replace the Power Steering belt (about $25). And, replace the SAI check valve ($65 from our host).

Last, inspect the crank seal on the front of the crankshaft. If it is leaking or weeping, this would be the time to replace it as well. You will have to remove the engine carrier, the A/C bracket, and the pullies. A lot of work, but this work cannot be done with the motor installed.

[Traveller]

Originally Posted by jhg41977

I read somewhere about upgrading the valve covers will help reduce leaks, something about oem are plastic?

I have yet to have someone get back to me with a measurement as to how much OEM valve covers warp. Yes the OEM covers are a FRP and they are fine.

All you need are OEM seals, 2 for the lower valve covers and 6 for the upper valve covers.

Since replacing my valve cover seals, my valve covers have been bone dry two years later.

If the old valve cover fasteners are corroded and if you want to replace them, you'll need 22 for the lower valve covers and 16 for the upper valve covers.

By the way, this is what a 15 year old OEM valve cover looks like when it is cleaned up...


If you want to freshen up the aluminum collars on the valve cover should they be corroded, see this valve cover link.

[Traveller]

Am I wrong or does installation of a LWF need a chip change in order to idle properly. If so, he may want to know that.

[jhg41977]

They look brand new Alex, nice job! I am not sure about a chip being required, I will check though. Thank you for the heads up.