Clutch Help

SRISER · 09-14-2003, 08:29 AM

I need to replace the clutch in my '88 Carrera. Which clutch package should I be looking at and what other things, such as seals etc, should replaced, inspected, upgraded when the engine is dropped? NoVA gang available to help?

l8tapex · 09-14-2003, 10:04 AM

I just finished replacing the clutch in my 92 911. I did all the work myself which taught me a lot. I'm not a pro mechanic I just enjoy working on my car. With that said in my humble opinion replace the compete clutch (pressure plate, clutch, and throwout bearing). But while you've got the motor out you should replace the flywheel seal, have the flywheel resurfaced, replace the flywheel bolts, the pressure plate bolts, and do the updated guide tube. I also rebuilt the release fork tube with new seals, roller bearings, and grease. I also did a valve adjustment since it was out of the car it was far easier to do. I also replaced a couple of leaking oil seals. It took me a total of 4 months but it was worth it.

KTL · 09-14-2003, 10:42 AM

Do a search and you'll find this has been covered here a number of times? Try the keywords "G50 clutch" and see what you find.

In short though, you'll want a spring-centered clutch disc instead of the current rubber one. The spring one is costs less and is more durable. The correct Porsche replacement disc is that from a 75-77 930 Turbo. You'll see this if you check the Pelicanparts catalog.

Pressure plate is a heavy sucker and unfortunately is not cheap.

If your car has the original clutch components, you most likely have the old style throw out/release bearing and guide tube. So, if you replace the release bearing, you must do the guide tube as well since the new bearing is a different size than the old one and will not work with the old guide tube.

Your flywheel cannot be significantly resurfaced (technically, not at all). If it needs a slight cleaning of the surface, that may be fine. But a number of tech. reference books say the early 87-89 G50 flywheel CANNOT be resurfaced.

As long as you're in there, you'll definitely want to see if your release fork cross shaft has been updated. This has been covered before as well. Try searching with the keywords "G50 update" or "G50 shaft" and see what you find. If you search with those keywords and my username KTL, I think it'll narrow things down for you. I'm certain that i've written something about this before.

If you got the NoVA gang to help you, you're in good hands. Marc, Richard, Jim, Tony,..... and anybody else i'm forgetting......... will tell & show you everything you need to do this job right. Richard LeSchander did this on his former 87 Carrera and they can make sure you're pointed in the right direction.

Jim Richards · 09-14-2003, 11:28 AM

STR, post on the local board when you're planning to do this. I'm sure there will be a good turn out. Just remember, Richard L. gets the cheap beer!

The Land of NoVA/DC/MD area Porschephiles Forum

l8tapex · 09-14-2003, 11:35 AM

My 92 has a dual mass flywheel and those units can't be resurfaced but why can't the earlier Non-dual mass units be resurfaced?

While my motor was out I also replaced the fuel filter, fuel accumulator (CIS cars only), replaced the rear shocks (easier to do with the motor out), and replaced the sagging and crumbling sound deading pad.

One last thought. Don't discount the amount of cleaning you will do. I went through about 7 can's of spray break cleaner getting the gritt and grime off.

rickeolis · 09-14-2003, 11:38 AM

I learned long ago to buy actual brand name clutch parts, not reman or generic names. This way you can be assured that you will get about the same number of miles that you got the first time.

l8tapex · 09-14-2003, 11:54 AM

I agree and I bought everything from Pelican parts with the exception of a couple of obscure parts that was easier to go to the local dealer for. I also recommend getting (or using) your digital camera and taking a ton of pictures. I'm not a pro and having a picture really helped when I was putting things back together.

For you experienced guys out there you'll laugh at this. At first, I did the throwout bearing but not the updated guide tube. Like a moron I spent days trying to get the two to come together until it dawned on me and I got the update guide tube.

One other thing...My G50/52 is very very very sensitive to the angle of entry when removing or mating the engine and tranny. It took me a long time to see (feel) the right angle. Another newbie learning curve thing :-)

We all forgot a flywheel lock. Get one you really can't properly torque the flywheel and pressure plate bolts unless you have one.

l8tapex · 09-14-2003, 11:55 AM

Get a copy of PET. It really came in handy for me.

l8tapex · 09-14-2003, 11:59 AM

Tools! I bought many tools to the clutch job that just weren't in my tool chest. For example, I bought two SnapOn triple square bits to use on the flywheel bolts and pressure plate bolts. I honestly would say that I bought several hundred dollars in tools, extensions, etc that I just didn't have before. I could list them all.

KTL · 04:39 AM

Hopefully the NoVA fellas will be able to lend a few of the tools needed to do the job.

For a flywheel lock, you can make one with a piece of flat stock strip steel. Drill a hole in each end and then slip one hole over the trans. stud and the secure the other end to one of the pressure plate screws.

Pelican sells a good, cheap clutch disc alignment tool. Of course a broomstick works in a pinch too. For the 88 you'll need the tool for the later cars, not the 72-86 cars. Different number of splines.

Not exactly sure of the resurfacing reason, but here are three references about the 87-89 flywheel. The first image is from Wayne's engine book, the second is from the Porsche spec. book, and the third is from the Bentley 84-89 Carrera Manual

References say that the release bearing could come into contact with the drive plate damper. I suppose this means the release bearing could hit the rubber damper of the clutch disc. But, this is a non issue when you replace the rubber-damped disc with a spring-centered disc. So I guess you can resurface your G50 flywheel if you're using a spring disc? Seems right to me. Looks like I stand corrected. Cool!

l8tapex · 09-15-2003, 05:01 AM

Good to know and thanks for the info.

SRISER · 09-15-2003, 05:14 AM

Super information! Thanks guys. Just trying to get a comprehensive list together of all the parts I will need.

Rick Lee · Rick Lee's Garage

Don't spend a dime on a flywheel lock. You can MacGyver one together from just about anything you have laying around. I think the last time I did this, we used an old pressure plate bolt, screwed it into the flywheel and used a short, double-ended box wrench to lock it. I have the 12 pt. bit you need to get the flywheel bolts off - cost around $7 at Pep Boys and it came with three other sizes. So don't pay $24 for the socket bit.

SRISER · 09-15-2003, 05:40 AM

Just have to find a place to get it done...and some NoVA folks I can bribe into helping. Rick, do you have a 36mm slim wrench?

Rick Lee · Rick Lee's Garage

Yes, I have that wrench too. A lot of us have that one. Watch someone destroy their $300 hard oil line with a torch and the wrong wrench and you'll be believer in the right $26 tool. I think we used a floor jack and breaker bar with it the last time we dropped one of my engines. Oh, what fun we'll have!

SRISER · 09-15-2003, 05:54 AM

I am actually really looking forward to it. What a great learning experience. I really want to know this car and not fear doing jobs like the clutch so I guess the best thing to do is just jump into it. I think the clutch has about 2-5k miles left on it. Running at 63k total so I think she is close. Grabs pretty good but getting a little stiff.

There is some disagreement concerning using a rubber centered clutch disk and the spring centered. The pro rubber folks say that the rubber center is much improved and does not disinegrate as they used to and that the spring centered clutch sometimes causes chatter. I know you did this on your '87 and would guess that you used the spring center from a '75 turbo. What did you think?

Do you have a list of stuff you needed left over from your clutch experience? I'd like to start ordering the parts but want to make sure I have everything I need. I have read the posts in response to the same question you asked a while back but am not sure why I need some of the items listed.

Could I borrow your 36mm slim wrench? I need it to turn the eccentric bolt for the trailing arms...gotta get the arse down on the car.

Installed the chin spoiler on Saturday...took three hours.

Rick Lee · Rick Lee's Garage

I replied to you PM on the Dorkiphus BBS. It was a shopping list for you. Did you get it?

SRISER · 09-15-2003, 05:57 AM

I haven't checked it today...thanks man! I will go pull it down now...

SRISER · 09-15-2003, 06:53 AM

Got the list! Thanks. I have a question...okay two questions. What does the G-50 update kit contain that is not on this list you provided and should I be getting pressure plate bolts for the '76 turbo since this is the clutch that will be used or for the '88 Carrera? (or are they the same?). Oh yeah, one more question in the original line of questioning...the oil cooler seals. There are three different types and I am not familiar enough to know which to get. All of them?

Do you think we could do this in a weekend? (First question in a new line of questioning that doesn't count towards the original line of questioning...I gotta stop watching that movie...)

KTL · 09-15-2003, 08:58 AM

Read this thread about the spring vs. rubber disc.

http://forums.pelicanparts.com/porsche-911-technical-forum/127172-88-clutch-opnion.html#post956568

The spring-damped disc is a tried and true design that has proven to be VERY reliable over the years for any make of car, Porsche or not. The rubber-damped disc does not have near the reliability of the spring unit. True, the later rubber-damped discs used in the G50s are much more reliable than the infamous exploding discs originally used in the SC cars. But the G50 discs have still been known to fail the same way the SC discs did. The rubber deteriorates, comes apart in chunks and jams up your clutch operation.

I think that Porsche tried to dampen the noise & feel of the drivetrain with its new G50 trans. back then. Try as you might though, the G50 is just a noisy gearbox. Not as bad as a ZF 6 speed, but noisy nonetheless! Nowadays I don't think you'd even notice the difference between the spring or rubber disc because the 88 911 is a little coarse and raw compared to the civility of today's cars. If civility is what you're looking for in the 88, you're better off with a 964 or 993.

Never noticed a difference in noise/chatter on my 87 and i'm pretty paranoid about noises the car makes. I honestly think i'd notice a difference.

When using the 75-77 930 disc, you need nothing different to make the swap from the rubber-damped disc. It is a direct bolt on. No modifications required.

The oil cooler seals you need are two of part # 999-704-013-50 and one of part # 999-704-017-50

I'm sure Rick's list contains all the other o-rings, gaskets and seals needed for the "while you're in there" work to address any current oil leak issues or to prevent any in the near future.

Good luck!