Engine drop #2: Clutch

r-mm · 01-19-2017, 04:33 PM

About this time in 2013 I dropped the motor of my 87 3.2 to do a whole bunch of things, notably cure high oil consumption and smoking. That was a success and the car has been dry, tight and strong ever since. However I neglected to change the clutch slave and hose, and several thousand miles later I believe a blister in the slave line caused the clutch to be semi-disengaged for many thousand miles resulting in a glazed or worn clutch that now manifests itself as a slip at WOT over ~4500rpm. Also possible a fluid leak is causing this, I can't be sure. But I will be shortly!

Boy is the drop easier the second time around! Felt much more confident on the disconnections and had all the tools at hand. Doesn't hurt that I moved into a nice garage with a heater and epoxy floors

What I can't recall is how I handled the height disparity between the max extension of the ATV jack (same I used last time) with the tail up in the air @ 36" clear under bumper. Maybe I started the drop with the tail lower then raised it up to retract the jack? Sounds like a dumb question but your help appreciated...

arbita1 · arbita1's Garage

You don't need it that high until you are ready to roll it out. So yea you could jack it up higher once the engine is dropped and on the jack.

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LM3929 · 01-19-2017, 04:43 PM

When I drop an engine, I bring the front end up so that the car is close to level and after the engine is back I drop the front end back down.

Lorne M

Luccia at Pelican Parts · 01-20-2017, 08:24 AM

Maybe see if our tech article might give you a bit more guidance with this project as well: Porsche 911 Engine Removal | 911 (1965-89) - 930 Turbo (1975-89) | Pelican Parts DIY Maintenance Article.

Baby · Baby's Garage

You can lower the car as low as it will go while allowing you to position the lift, leveling the car in the process. Once everything is unfastened, drop the motor onto the lift and raise the rear of the car. Pull the lift backwards a bit and lower it if you can and lift the rear a little bit again until it looks like the motor won't clear the car. To create more clearance, lift the back of the car a little more, and lower the lift a little, pull the lift backwards a little. Repeat until the motor is clear. By now the rear of the car should be pretty high.

yelcab1 · 01-20-2017, 10:01 AM

I think you are making this too complicated..... Really!

Dump that platform. Use 2 jacks. Drop the engine on to two wooden moving dollies. Use two jacks one on each side jack the car up high enough to roll out the engine, drop the car back on to two stands.

If it takes more than 3 hours, you are doing it wrong.

r-mm · 01-21-2017, 07:51 AM

Ok I gotta say this was a big improvement on my first drop.
By ditching the long handle on the ATV jack and removing the exhaust (easier with my Busch) I was able to get to a PERFECT balance point. Motor came down nice n smooth on the ATV jack (with custom MDF top) no need for another jack or dolly. It now sits on the ATV jack where I will remove the trans and see what's doing with the clutch. After I have BBQ and a beer(s)

r-mm · 12:50 PM

Remind me how the updated G 50 pivot shaft is removed? I removed the smaller bolt from the retaining tab but I cannot recall how I'm supposed to pull the shaft?

Tried a longer m8 in the end but she is not budging.

r-mm · 01-25-2017, 05:25 PM

Well this one really fought me. I had to fabricate a puller to get the arm out and it shrieked and chattered the whole way out. I bought the cross arm update kit on PP when I did the top end rebuild and I am pretty disappointed to have found it more or less rusted to the bore, especially since the original arm (likely in service since 1987) came out with a few taps and finger pressure. Am I wrong to be disappointed? I don't relish the thought of putting it back in... but not sure what the options are.

Tippy · 01-25-2017, 05:42 PM

I think you found your clutch issue, maybe...

r-mm · 01-25-2017, 05:45 PM

I think I found my issue but its not the shaft. Unless I'm wrong, the shaft is not supposed to rotate in its bores, the pivot arm rotates on the shaft, which it was doing nicely, on new bronze oilite bushings.

The real issue is that the pivot arm was hitting the PP fingers, and appears to have cracked one of them through. Abrasions are visible on the pivot arm as well.

yelcab1 · 01-25-2017, 10:01 PM

I think the issue is you have a bad pressure plate, which cracked, became uneven and started rubbing on the fork. Not the other way around.

r-mm · 01-26-2017, 04:55 AM

Interesting idea, I suppose its possible but would be disappointing from a genuine Sachs part with low miles on a stock motor.

yelcab1 · 01-26-2017, 08:03 AM

Quote:

Originally Posted by r-mm

Interesting idea, I suppose its possible but would be disappointing from a genuine Sachs part with low miles on a stock motor.

I have seen it that way. Several times. The quality of the parts are not the same as they used to be. Fix it, go on.

racerr1958 · racerr1958's Garage

My last Sachs PP had a similar crack as yours. It was also low mileage.
It did not damage the fork fortunately.

KTL · 01-26-2017, 10:44 AM

Yup unfortunately the quality of the clutch parts is not what it used to be. I've heard from a number of folks on the forum that their new clutch has not been assembled same as the old/original and the quality is less. Very disappointing.

I see a ridge on that release bearing retaining "washer" which is actually more like a spring washer. Is that installed backwards and that's how the rubbing occurred?

r-mm · 01-26-2017, 10:56 AM

For sure there is a ridge on that washer - I thought it was distorted by the broken diaphragm finger but will need to do some research to make sure I got it installed the right way. The rolled lip faces the transmission, is that correct?

r-mm · 01-26-2017, 11:23 AM

Quote:

Originally Posted by racerr1958

My last Sachs PP had a similar crack as yours. It was also low mileage.
It did not damage the fork fortunately.

Did it cause the clutch to slip?

r-mm · 01-27-2017, 05:56 AM

Removed the flywheel and pleased to see things still looking dry from when I replaced the rear main seal three years ago.

So the only smoking gun I have so far is the cracked pressure plate. Im going to think on it this weekend but so far my thinking is replace pp, tob and related hardware but reuse everything else, after cleaning and measuring the flywheel for flatness.

r-mm · 03:29 PM

Checked runout on the flywheel and found about .003" (.0015" on either side of zero).

The manual calls for .01mm = just under .004" so it does not seem the flywheel is unacceptably warped, but I'm still debating having a light cut taken (on both surfaces for sure).