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Discussion Starter #1
I am trying to get a little more release in my clutch as it's new and I am getting a little grind when getting into first or reverse.

I have removed the majority of the pedal linkage slop by replacing the worn clevis pins and making all new clevis pins slightly oversize where needed. It is certainly better than it was, but even with it adjusted with no throwout bearing clearnace, I can't get what I think is full clutch disengagement.

A local shop had put in a new flywheel and clutch to chase a different problem, and I asked them at the time about adjusting the clutch pressure plate. I know I had this done with the last clutch, as they had the special tools. I don't think this shop was even aware of the adjustments. I am wondering if pressure plate could be set up where it takes more travel that what I have available to fully release. I haven't make these adjustment myself, so I am not sure I fully understand the influences. Any guidance is appreciated.

Andy Amatruda
1964 Giulia Spider
 

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The original-style, coil spring pressure plates can be adjusted. There are three nuts on the back face of the PP, which are accessible when you remove the sheet metal cover at the base of the bellhousing (well, one nut at a time is accessible - need to rotate the flywheel 120 degrees to get from one nut to the next). These are visible in the photo below. As I recall, tightening the nuts will solve the problem of not fully releasing.

I believe the condition you describe occurs as the throw out forks gradually bend from years of use. They are made from steel that is too ductile. The other fix is to remove the TO fork, heat it, and bend it back. But you need to disassemble the clutch to remove the TO fork.

 

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Actually, it's a forging Jay, see photo #1. The arms on the T.O. bearing will wear. There are a whole bunch of fixes, and even more causes! I set the PP up on the factory tool, photo #2. Then check the thickness of the clutch disc, and depth of the flywheel PP step to friction surface. If these are Ok, go to the T.O. yoke in the bell housing. It has brass bushes on it's legs that wear oval. I make new ones. Then finally the T.O. itself. The carbon wears in originals, which if the bearing itself is good, can be restored using a GTA Celron friction member, photo #3. If the arms on the T.O. frame are worn, they can be sleeved in mild steel, photo #4. This restores all the critical dimensions and allows normal disc wear adjustment with clevis and rod.
The newer style T.O. bearing will avoid rebuild of the older ones. The GOOD one costs more than the "no-one-knows-where-it's-made" version. Buy the good one!
 

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Yes and no Jay, Often the nuts are tack electric welded to the studs. Nuts, studs and the weld are pretty hard. PITA to reach in and grind them loose, then re-tack weld. You MUST be careful to move each nut exactly the same amount, or the T.O. disc on the P.P. won't be square/ level to the friction surface, causing rapid T.O. friction surface wear, and a "funny" clutch foot feel.
YES, I have used your method short term, and it does work. It's just not a "return-to-normal-use" fix.
The whole problem is a bother as lots needs disassembly and reassembly is needed. If the flywheel ledge itself is wrong, you are better off pulling the engine and transmission and starting over. This is a major reason to replace clutch disc, P.P. and T.O all at the same time, with plenty of measuring and examination before any reassembly. These cars are not new, and odds are good, someone has been in there before, and one has no idea what was done in the past.
 

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Yes and no Jay,
OK, thank you for the detailed reply. The nuts were not welded on my Giulia, but obviously if they had been, my "quikee fix" wouldn't have worked.

Another problem with my solution would arise with the newer, diaphragm-style pressure plate (which don't have the three nuts). Upon re-reading the portion of aamatruda's post that describes his shop replacing his clutch, it's possible this is why they can't simply adjust the PP.

You MUST be careful to move each nut exactly the same amount
Good point. I should have mentioned that in my reply to aamatruda.
 

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Discussion Starter #8
Jay &v Gordon,

Thanks very much for this information and photos! The clutch, pressure plate and TO bearing were replaced as a set along with a used but good condition flywheel last summer. I was having bucking from what is apparently throttle linkage / engine motion issues (still not 100% resolved). Not being able to solve the bucking myself, I went to a reputable shop which also struggled. They pulled the tranny and inspected the clutch and flywheel. They did find some very fine cracking on the flywheel face and suggested changing the flywheel as well as the new clutch components. I know that they didn't have the special measuring PP tool, but it did look like the replacement clutch components were identical to what came out, which is what you have pictured. I have never dealt with an adjustable pressure plate and I know this shop did not have the Alfa tool you have shown. They did not make adjustments, but the TO bearing seems to engage smoothly so I suspect the fingers are in plane, but perhaps the gap is wrong.

The shop did adjust the pedal linkage with no free play in an effort to get barely enough travel to get the clutch to release. I thought that once I removed the play out of the external linkage I should be fine, but it's only marginally better and again with no free play.

I'm not looking forward to dropping the tranny to dig through issues with the throw out fork (I did not inspect the throw out fork when I had it apart last, but this is a Tom Sahines rebuilt tranny so I would have expected this to be in reasonable shape.

Since I beleive I have the Sachs PP, my thoughts are to try and make identical adjustments to the 3 nuts via the inspection cover. Considering my issues, should I be tightening or lossening these nuts?
 

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"Since I believe I have the Sachs PP, my thoughts are to try and make identical adjustments to the 3 nuts via the inspection cover. Considering my issues, should I be tightening or loosening these nuts?"

Here is the probable issues. T.O. fork bushing wear, and / or flywheel friction surface may at sometime been cut, randomly excessively lowering the P.P. frame ledge it rests on. Since it does not DISENGAGE, you need MORE throw to the T.O. pad, a thinner clutch disc facing or other unknown change.
Thinking about this, I set up a GTA PP in a race flywheel for study. I also looked at my set up tool, and instructions. You have a geometry problem. Without trial it's going to be hard to know which way to go on adjustment but more important, if there will be enough available adjustment. Look at these photos below.
The pointer in picture #2 is the pad for the T.O. bearing that needs to move further DOWN for disengagement. Photo #3 is one of the 3, 14mm nuts you may or may not be able to tighten or loosen to move the pad up or down. You cannot move it very much.
Photo#4 shows some difficulty in moving any of these nuts with the assembly in place.
Photo #5 shows the fulcrum, as well as access for a special THIN 14mm wrench. You would think that tightening the nuts would lower the pad.
See if you can actually reach in there....
Let us know.
 

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Discussion Starter #10
Hi Gordon,

Thanks again for the great photos. I checked when I had this work done and have photos myself to confirm what components were used. It appears the new pressure plate is similar to my old one, but the nuts have an integral sleeve which is flattened to prevent rotation after being set. The flywheel has been resurfaced so it is possible that the "step dimension" might not be correct. Do you know what it supposed to be? I plan on measuring this off the old flywheel, but I dont recall seeing that dimension specified.

I am also assuming this is the less expensive throw out bearing as the bosses are formed as opposed to machined.

I am disappointed that with this much new and/or refurbished I still have an issue.

As a sanity check if you are sitting at a stop light and then go from neutral to first, do you get a little grind? Same with reverse? If not, I have to believe this is a clutch issue.

As a confirming test, I am going to add the recomended free play back in and see if I can shift at all. If the condition worsens, I agree its a T.O. fork bushing wear, and / or flywheel friction surface problem.
 

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Considering my issues, should I be tightening or loosening these nuts?
I believe tightening them has the same effect as shortening the pull rod; e.g., getting the clutch to release before the pedal reaches the limits of its downward travel.

My pressure plate looked more like the one shown in my post #3, and not like the one Gordon shows in post #9. An ordinary 14 mm wrench turned the three nuts on mine without any problem.

I would try turning the nuts one full turn each and seeing what happens. I put some magic marker ink on one of the nut's faces so I could tell when it had gone around 360 degrees.

I'll agree that this is probably a cowboy fix, and that the issues Gordon cites are the real cause of the problem. But if it gets you on the road, it's probably worth a try - it's relatively simple and it's reversible.
 

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The PP I pictured is a NOS second type GTA, but the heavier version not the light TZ type. The old race type used the ring I pictured to support the spring towers as they would sometimes tilt or crack in racing. The earlier 101-1300 /1600 had no spring tower support rings, and allow access to the nuts without trickery.
 

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Discussion Starter #13
Thanks Jay,

Just a few points of reference from the old clutch. My friction plate was in pretty good shape at a thickness of 9.3 mm vs the 9.1-9.4 spec. The depth of the old flywheel was 29mm but I have no reference. The Pressure Plate dimension "C" from the manual was a whopping 67mm vs the spec range of 48.8-50.4mm. Considering this plate / clutch was set up at a shop that has the correct Alfa tool, I have no idea why that dimension is so far out unless it is compensating for flywheel issues as well.

I you have any dimensional data, please share it as whenever I do pull this apart, I'll also need to measure and compare what's in the car now.
 

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"I am disappointed that with this much new and/or refurbished I still have an issue.

As a sanity check if you are sitting at a stop light and then go from neutral to first, do you get a little grind? Same with reverse? If not, I have to believe this is a clutch issue."


I think you can address the whole issue by selecting 2nd gear momentarily before you select 1st. There are mechanical reasons to do that which someone can better explain than I. I don't believe it is unique to your situation and it does save wear and tear on gears that are clashing if you go directly to 1st or REV from Neutral. It's a small inconvenience to pay for trouble free gear engagement much like double-clutching which is not in the operator's manual yet is a known method of keeping gear crunching out your driving experience even though technically the gearbox is synchronized. Just my 2 cents
 

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Sad story:
The 100% correct dimension was written on the wall of my old shop where I did my Alfa and Ferrari work for over 50 years. The property where the shop was located was sold, and I built a new and much smaller shop at my home, BUT the correct flywheel dimensions were lost in my move.
I just measured three different wheels. A race wheel used by Mike Besic has a depth, ledge to friction surface of 29MM. An ancient AUSCA Iron wheel now replaced with an aluminum wheel in my shop is 29.55. One I have that is WRONG is 30.23. So I've a research source that MIGHT tell me the REAL number(s) if I'm good. Lets see...
 

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Discussion Starter #16
Thanks all. I seems we are getting closer to key information that will be useful to us all. I will be experimenting on Sunday and I'll let you know how I make out.
 

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Thanks Jay....If you have any dimensional data, please share it as whenever I do pull this apart, I'll also need to measure and compare what's in the car now.
Sorry, I do not have any dimensional data. I must confess that I am just a home mechanic / amateur; I have learned a lot from Gordon in this thread.

I will suggest that putting in a new, full-thickness clutch disk probably led to your release problem. The worn linkage can't pull the pressure plate far enough back from the flywheel to clear the thick disk. Got any half-worn disks lying around? (I'm kidding here)
 

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Discussion Starter #18
Gordon,

Do you own the clutch adjusting tool pictured above? I am wondering if we can back into the flywheel dimension from the step dimension of the tool adding the thickness of the friction disc.

I have the car on the lift and will be pulling the inspection cover shortly to see what I can see.
 

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Yes, but it only sets the PP base plate to top of T.O. plate dimension. ie, if the friction surface of the PP was cut or non standard, that difference needs be subtracted from the set-up clearance. Flywheel surface changes as well.
The tool was only designed to create correct T.O. position from a stock wheel and PP friction surface.
We KNOW the flywheel PP ledge to friction surface is supposed to be 29.5mm, but have not found the documentation or service update sheet that says this.
When we find the REAL data source, you will see it here.
 

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Discussion Starter #20
I was playing with the old clutch and flywheel to determine the interactions of adjusting the nuts on the 3 arms vs. the position of the thrust ring face. The nuts are peened to the threaded post and I was unable to break them free. However the nuts appear to have a wedge at the base that seats into a valley in the finger. When "camming" that out while turning the nut, the arms did raise - suggesting that tightening the nut would cause the thrust ring face to extend up. I need to take more measurement as I can't yet simulate the set up tool reference dimensions.

I then removed the inspection cover and assessed the condition of the TO fork. I found very little play in the bushings. At this point I decided to set the 2mm gap between the TO bearing and thrust ring faces. Once set, I confirmed I had about 1" free play in the pedal. I will take this for a test ride ang see what happens. Considering that the free play was previously adjusted out to get the most throw, one would it expect even less disengagement of the clutch now. If this is true, it would seem it's down to a poorly set up presure plate or an incorreclty remachined flywheel.

Best Regards,

Andy Amatruda
1964 Giula Spider
 

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