Clutch Dilemma

robsad

robsad

True Classic
My 74 has a 1980 1500 engine with my original 74 four speed. Note that the clutch lever is at the extreme of its travel before the clutch will disengage. Pay no attention to where the stop screw is - I moved it to show where the arm first contacts the plate. I should add that I installed a lightened flywheel from MWB marked "75 - 78 but this problem was there when I first did this conversion long ago with the original 1300 flywheel. This arrangement does work but was not like this when the car was new with the 1300 block and flywheel. Is there something about the 1500 block different than the 1300 that would cause this ? I did trial fit the tall pressure plate just to see what would happen but it bound up on the 1300 bellhousing proving that I have the late 1300 bellhousing. As far as I know there are only two types of pressure plates for the X. The pic shows how far the clutch arm has to travel before the release bearing contacts the fingers on the pressure plate. Has anyone done this conversion and noted this characteristic ? As long as it works should I not worry about it ? Thanks in advance . . .

IMG_1381.JPG
 
If you have the early 4 speed with the sheet metal shaft plug inside the bellhousing, it uses the tall pressure plate and thinner flywheel. If the shaft plug looks cast into the bellhousing, it uses the thin pressure plate and thicker flywheel.
 
dllubin said:
If you have the early 4 speed with the sheet metal shaft plug inside the bellhousing, it uses the tall pressure plate and thinner flywheel. If the shaft plug looks cast into the bellhousing, it uses the thin pressure plate and thicker flywheel.

DL,
I didn't know there is a thicker 1300 flywheel. Any idea what the thicknesses are between the early 1300 flywheel and the late one ? To reiterate I have the late bellhousing so apparently I may have the thinner flywheel causing the large amount of free play with the arm. Does this make sense ?
Click to expand...
 
Here is the arm on my 77X with stock flywheel an 1500 motor.
This is the point where the arm is at resistance.
IMG_0583[1].JPG
 
That could be a possibility. I don't know the difference in thicknesses between the two but there was a thread within the last few weeks that went into this whole issue. I originally got bit by this problem when I found out my 74 was built late enough to be in the 1975 engine number range with the later 4 speed transaxle. I have also replaced the original 1300 with a 1500. The clutch seems to be fine with the short pressure plate and later trans and flywheel.

Here is the thread:

https://xwebforums.com/forum/index.php?threads/clutches.35667/#post-308998
 
dllubin said:
If you have the early 4 speed with the sheet metal shaft plug inside the bellhousing, it uses the tall pressure plate and thinner flywheel. If the shaft plug looks cast into the bellhousing, it uses the thin pressure plate and thicker flywheel.
Click to expand...
DL,
Do you know what the part numbers are for the two different flywheels for the 1300 four speed ? After much reading and advice I'm thinking that I need the thicker flywheel to solve my clutch arm travel problem.
 
robsad said:
DL,
Do you know what the part numbers are for the two different flywheels for the 1300 four speed ? After much reading and advice I'm thinking that I need the thicker flywheel to solve my clutch arm travel problem.
Click to expand...
Sorry, I don't know the part numbers. Have you checked with the parts suppliers for X1/9s? I would guess they would know, and perhaps also have some inventory.
 
dllubin said:
Sorry, I don't know the part numbers. Have you checked with the parts suppliers for X1/9s? I would guess they would know, and perhaps also have some inventory.
Click to expand...
YES, I have tried to contact the vender about the problem but has not returned my calls or emails. I'm going to remove the lightened flywheel I bought from them and put my original 1300 flywheel back on and be done with it. Bummed that I'm now stuck with an expensive flywheel that won't work with my setup.
 
The problem may not be your flywheel OR your pressure plate. What is the thickness of your new clutch disk? I had two very different clutch disks for my 1500, and the original one was so thick that it caused the fingers of the pressure plate to be excessively depressed, so that the slave cylinder had no more room to push them in, and release the clutch. Perhaps you have a clutch disk that is too thin, leaving the fingers of the pressure plate too far extended?
 
Mechanogeek said:
The problem may not be your flywheel OR your pressure plate. What is the thickness of your new clutch disk? I had two very different clutch disks for my 1500, and the original one was so thick that it caused the fingers of the pressure plate to be excessively depressed, so that the slave cylinder had no more room to push them in, and release the clutch. Perhaps you have a clutch disk that is too thin, leaving the fingers of the pressure plate too far extended?
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I never thought of that. But My transmission is not a 1500, it's the original 74 four speed. Do you still have the thick clutch disc ? I'd be interested in the thickness and compare with what I have.
 
(Dec 2, 2017)
Only took 2 hours to get the transmission removed. Found that the clutch disk was
a) Rusted to the pressure plate and flywheel
b) Too thick. Removed = 8.9mm, new = 7.3mm

You should be able to find the proper clutch thickness in a service manual. A difference of 1.5mm made a HUGE difference in the angle of the pressure plate fingers. There are folks well versed in this (Steve Hoelscher) who probably know the correct dimensions by heart. I would hazard a guess that the thickness YOU need would be the wrong one that I removed from my 1500 FI. So, I would guess you need 8.9mm thickness?
 
I think you are making a very good point about disk thickness Mechanogeek but I'm not sure why you suggest he go to a thicker clutch. Following your logic I believe if his disk were too thick it would cause the plate fingers to be flatter and further away from the throwout bearing when disengaged. Putting a thinner clutch disk in would cause the spring fingers to extend further toward the throwout bearing when disngaged and require less travel from the clutch pedal.

The reason I am interested in this is because the friction point on my own clutch pedal is about 6mm off the carpet making it difficult to finesse in tight parking areas especially when grades are involved. The pedal travels about 60 mm before it comes into contact with the clutch plate fingers. I looked at my slave adjustment and it has already been adjusted to the very end of the range at the tip of the shaft. I hope I haven't confused things here. Just trying to clarify.
 
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Hmm. In re-reading, you may be correct, Crate. The possibility is that the clutch disk being used is in fact too thick. Similar to my situation. So, vice-versa, and check the thickness.
 
Mechanogeek said:
(Dec 2, 2017)
Only took 2 hours to get the transmission removed. Found that the clutch disk was
a) Rusted to the pressure plate and flywheel
b) Too thick. Removed = 8.9mm, new = 7.3mm

You should be able to find the proper clutch thickness in a service manual. A difference of 1.5mm made a HUGE difference in the angle of the pressure plate fingers. There are folks well versed in this (Steve Hoelscher) who probably know the correct dimensions by heart. I would hazard a guess that the thickness YOU need would be the wrong one that I removed from my 1500 FI. So, I would guess you need 8.9mm thickness?
Click to expand...
I'm wondering if the different thicknesses in your clutch discs are simply a manufacturing quirk or by design. Where did you get the thinner disc ? My disc is like your thick one - 8.6 MM. I don't see any listings for different thicknesses with any of our venders.
 
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