The engine is OUT! Clutch is OUT! making progress

[CorsePerVita]

So me and my buddy jim made progress on my 911. He was kind enough to let me use his lift. He's a member on this forum, thought that was extremely nice of him.

Engine is out, transmission is separated, clutch is apart.

A couple symptoms:

- Power loss
- Horrible gas mileage
- REALLY BAD chatter on the clutch

Now that the clutch is out... a few observations

- Inner ring of clutch is a bright tan color, and same inner ring of flywheel is very discolored.

- Clutch disc material seems to be "okay" - measurement of new vs old clutch disc was about 1/4mm of surface material (not a huge difference).

So... my next question is...

- Is it possible I'm dealing with something else on it? Perhaps the clutch cable? there were times i could get it to engage smoothly but it was RARE.

- Is the inner ring of discoloring bad? The flywheel still has the marks on it where it was turned. You can still literally see where it was turned, and it doesn't look like it was all that long ago... there are a few areas where those spots are no longer present but for the most part, the vast majority looks good.

I was TOLD the disconnected vacuum lines were for the cruise control. Now that the engine is out and i can see the back, it actually appears they were both connected to something it goes to a T and into the throttle body... which is hooked up and going to nothing which is odd. Perhaps they really are for the cruise control and left open from the throttle body?

Here is my list of things "TO DO" now that it's out.

- Replace disc material anyway since i found the ring to be odd. Perhaps the previous owner beat on it a lot and wasn't nice to it.

- Replace pilot bearing

- Replace main seal behind flywheel

- Give my aux air valve a pb blaster bath since it has been sticking

- Replace oil sender since it is leaking and was told "They all leak at some point"

- Clean up blower motor

- Replace all the rest of heater hoses

- Remove the rest of my A/C system

- Valve adjustment

- Oil change

- Drive car.

- Cross fingers nothing goes wrong.

Anything I'm missing? I will post pics when I am home. I'm still at his house working on the car, just figured I'd post an update.

[JJ 911SC]

Hopefully you won't catch the "while you are in there" virus.

I did and I now have a new sport clutch, new flywheel, new short shifter kit and the list goes on

[Grady Clay]

OK, we are talking about a 1982 911SC.

Is the disc ‘shinny’ polished or oily?

Measuring the thickness of a clutch disc is difficult at best.
You must ‘crush’ the two friction surfaces together.
Two ViceGrips with the pivot-pads work well.
The difficulty is ‘squeezing’ the new and old discs the same pressure to ‘crush’ the spring between.

Most of the time, it is ‘safer’ to simply replace any used disc that is ‘suspect’.

Carefully inspect the pressure plate.
The large finger-spring can be broken from one of the ‘stress-relief circles’ toward the center.
This is sometimes difficult to see.

Another potential problem can be the three flat ‘tension springs’ that transmit the torque from the pressure plate housing to the moving friction part of the pressure plate.
These three ‘leaf-springs’ are designed to operate in tension when the engine is driving the car.
If the car inertia drives the engine excessively, these leaf springs are in compression and can ‘buckle / bend’.

What is the wear on the flywheel?
What is the measurement of the flywheel thickness?

You may want to replace the flywheel and pressure plate with new.

Does the clutch cable Bowden tube have the normal ‘bend’ when installed?
Is the chassis cracked where the Bowden tube seats at the front?
Were the engine and transmission mounts tight?
Was the engine and transmission tightly bolted together?
Does the clutch arm, over-center Omega spring, shaft and fork operate correctly?
Was this properly adjusted?
Is the pilot bearing in the center of the flywheel correct?
Is the clutch release (TO) bearing guide tube tight?

Please post pictures.
I’m not clear about your color and location descriptions.



Is everything as-original with the engine?

I suspect the power loss and horrible gas mileage are related.
Have you done a cylinder leak test and a cranking compression test?
Is your ignition distributor functioning correctly and timing within spec at all rpm?
What was your pre-cat exhaust mixture readings?

First step – remove the valve covers and check the cylinder head nuts.

When you address oil leaks, replace the three oil cooler seals, the thermostat O-ring and the breather gasket in addition to your oil pressure warning light switch.
Inspect the inside of the end of the big breather hose for cracks.
How are your oil return tube seals?

Best,
Grady

[rusnak]

The splines on the input shaft must be CLEAN and lubed with the extra special grease, or it could bind the clutch disc.

[CorsePerVita]

Originally Posted by Grady Clay

OK, we are talking about a 1982 911SC.

Is the disc ‘shinny’ polished or oily?

Shiny.. yes.. oily no.

w/o flash
I took a pic with the camera without flash and with flash. Here are the results.


w flash


w/o flash


w flash

Originally Posted by Grady Clay

Measuring the thickness of a clutch disc is difficult at best.
You must ‘crush’ the two friction surfaces together.
Two ViceGrips with the pivot-pads work well.
The difficulty is ‘squeezing’ the new and old discs the same pressure to ‘crush’ the spring between.

I compared the old disc to the new disc. Without doing any crushing as you spea of, the difference was about 1/4mm of thickness of friction material.

Originally Posted by Grady Clay

Most of the time, it is ‘safer’ to simply replace any used disc that is ‘suspect’.

I already have a new disc, pressure plate, throwout and pilot bearing I plan on installing today.

Originally Posted by Grady Clay

Carefully inspect the pressure plate.
The large finger-spring can be broken from one of the ‘stress-relief circles’ toward the center.
This is sometimes difficult to see.

Another potential problem can be the three flat ‘tension springs’ that transmit the torque from the pressure plate housing to the moving friction part of the pressure plate.
These three ‘leaf-springs’ are designed to operate in tension when the engine is driving the car.
If the car inertia drives the engine excessively, these leaf springs are in compression and can ‘buckle / bend’.

I didn't check this but this is a very good point, I will inspect the old pressure plate before the new one to see if this is possibly what was causing it.

Originally Posted by Grady Clay

What is the wear on the flywheel?
What is the measurement of the flywheel thickness?

I am not sure, what is a good way to check the thickness? It's obvious it hasn't worn much, you can still see the machining marks of the last surfacing job which is what surprised me.

Originally Posted by Grady Clay

You may want to replace the flywheel and pressure plate with new.

I did not order a new flywheel but do have a new PP. Although a new flywheel may not be a bad idea. Although I need to measure thickness first. How would I go about doing this?

Originally Posted by Grady Clay

Does the clutch cable Bowden tube have the normal ‘bend’ when installed?
Is the chassis cracked where the Bowden tube seats at the front?

I need to inspect this will report back with findings.

Originally Posted by Grady Clay

Were the engine and transmission mounts tight?

Mostly but transmission side had some cracking in rubber. Have new mounts to install. Yay!

Originally Posted by Grady Clay

Was the engine and transmission tightly bolted together?

Yes, perfect.

Originally Posted by Grady Clay

Does the clutch arm, over-center Omega spring, shaft and fork operate correctly?
Was this properly adjusted?

Appeared to be just fine. However I am not sure if it was properly adjusted. The pedal released the clutch wayyyyy far out and the window for slip was extremely small which I found to be very strange. Perhaps things were in fact not adjusted properly.

Originally Posted by Grady Clay

Is the pilot bearing in the center of the flywheel correct?
Is the clutch release (TO) bearing guide tube tight?

A yes on both, however, I have a new pilot bearing going in to ensure this.

Originally Posted by Grady Clay

Please post pictures.
I’m not clear about your color and location descriptions.

Is everything as-original with the engine?

After a brief rundown I found the following:

- O2 sensor cap busted, and separated, so O2 has been entirely disconnected this whole time I've had the car.

- I have a tiny crack in my cat, very small, but it's there.

- Oil pressure sensor leaking like hell

- Aux air valve sticking, going to pb blast it and loosen it up a bit.

Originally Posted by Grady Clay

I suspect the power loss and horrible gas mileage are related.
Have you done a cylinder leak test and a cranking compression test?
Is your ignition distributor functioning correctly and timing within spec at all rpm?
What was your pre-cat exhaust mixture readings?

Haven't done a compression test, probably will later when I get it home.

Not sure on the distributor, it was idling odd and seemed to have some bad hesitation when I first got it. I replaced the vacuum lines to the distributor and it was fine afterwards. Still had some hesitation and horrible chatter but I figured it was related to the clutch.

Also seemed to be running quite rich... but now that I found out the O2 was disconnected, that may explain a lot.

Originally Posted by Grady Clay

First step – remove the valve covers and check the cylinder head nuts.

When you address oil leaks, replace the three oil cooler seals, the thermostat O-ring and the breather gasket in addition to your oil pressure warning light switch.
Inspect the inside of the end of the big breather hose for cracks.
How are your oil return tube seals?

Best,
Grady

When I did the valve adjustment everything looked good. The breather tube appears to be quite supple and soft. There was one spot I saw some cracks "starting" but it appears to be still sealing and looks good. I might just replace it "While I'm down there."

[CorsePerVita]

New clutch is installed. New seal installed... fixed all the vacuum issues I had. Won't know for sure till we start her up. But am happy with the progress thus far..

Going to mate the tranny back up to it in the morning.

My "this didn't go perfect" so far...

- Broke a pilot bearing bolt off in the crank. Had to extract it. Thought the torque spec was 20ft lbs. Found out it's more like 8-10lbs... from what I'm told.

- Flywheel issue... that was no fun finding out someone borked it, glad I got it fixed.

- Heater box adjustments... those were being a pain. We got those adjusted. HOLY CRAP! I'll have heat!

[CorsePerVita]

A good example of my before and after...

BEFORE:







Now:




When I first bought the car...




After the powdercoating and detail:




..... NOW.