Clutch mystery

[Gary73Super]

My '73 Giulia Super with a transplanted 2.0 from a European Alfetta has had this problem going back to last fall when the car was new to me. After driving it for a few weeks without issue, all of a sudden I couldn't shift into first or reverse without gears grinding with the clutch fully depressed. Second through fifth gear were fine. I had this problem for a few days every time I shifted into either of those gears (although I didn't drive it any distance while this was happening for obvious reasons). I got underneath the car to take a look at the clutch slave cylinder on the suggestion that a mounting clip might have popped off since the slave cylinder had just been replaced with a new one. The clips were fine, but I also fiddled with the arm coming out of the slave cylinder for no particular reason. Apparently this did something (moved some air bubbles in the system around?) because the problem seemed to go away. However, since getting the car out of storage in the spring, it has partially returned. Now the first and reverse grinding only happens on occasion, but the occasion is very predictable. When I'm just normally driving the car, such as shifting into first at stop signs and stoplights, it doesn't happen. But, when I let the car idle for a minute or two (a stoplight is normally not long enough to cause it) with the clutch out and then push in the clutch and try to shift into first or reverse, it will grind pretty much every time. If I pump the clutch pedal a few times before engaging the gear after it had been griding, that sometimes helps, more often not. The only sure way to engage the gear without grinding is to turn the engine off and start the car with it in gear. Then if I drive it around for a bit longer going up and down through the gears, it will be fine again for engaging first and reverse as long as I don't let it sit for a couple more minutes.

Sorry for the long winded description--I'm hoping that might help with diagnosing the problem. I've tried bleeding the clutch (yes, the bleed valve was in the 12:00 position) to eliminate air bubbles and it still happens. I just used the conventional technique though of one person operating the pedal and the other opening the bleed valve before the pedal is pushed down to expel fluid and closing the valve before letting the pedal up. The clutch and brake pedals are in line with each other as far as height, so I'm thinking it's not the mechanical adjustment at the master cylinder--although it does feel like if I could just depress the pedal another fraction of an inch, the problem may go away. I also don't think it's the rubber hose to the slave cylinder expanding because I would have noticed that when bleeding the clutch. Plus, it is an inconsistent problem with only the two gears. So, what do I do next? My ideas:

1) Try bleeding it again, but use the technique of pumping fluid through the slave cylinder bleed valve (at the 6:00 position) from the bottom to expel air out the top of the system at the reservoir?

2) Adjust the clutch pedal height at the master cylinder a bit even though the pedals are the same height?

3) Replace the slave cylinder as the new one on there now may have a manufacturing defect?

4) It's a more complicated/expensive problem with something inside the transmission (pressure plate)?

Thanks,
Gary

[Andrew]

Reverse has no synchro, and first has it only in the first/second direction. Try shifting briefly into second or third before going into first or reverse, and see if that makes the grinding disappear. Sounds to me like your clutch is not fully disengaging. Where in the stroke of the pedal does the clutch start to engage? Very low to the floor?

Is the clutch master cylinder new? Bleeding the clutch successfully can take some doing.

Andrew

[Gary73Super]

Thanks Andrew. I'll try second/third into first and see what happens. Offhand I think that will still cause it to grind because I believe I've done that in all my playing around, just not certain. It does feel like the clutch is not fully disengaging, and because it only grinds occasionally it seems like it is losing hydraulic pressure that is causing it to not disengage. Another thing I'll try is holding the clutch to the floor in first gear for 2 or 3 minutes and see if it starts to engage (move the car). I'm not sure what that tells me other than something is changing (loss of pressure) due to the extra time.

The clutch engages fairly close to the floor (maybe an inch or two), but normally not right on the floor. The master cylinder isn't new and sounds like a likely culprit. First though I'll try the "backflush" technique of expelling air since that's the easiest potential problem to verify/eliminate. The cheapest way to do that seems to be finding a large syringe at a farm supply store and we have more of those here than European automotive parts stores.

I take it that my symptoms don't allow it to be determined whether it is air in the system or a bad master cylinder? My uneducated guess would be that if it was air it would be happening more consistently instead of only after this delay of a couple minutes.

Gary

Quote:

Originally Posted by Andrew Reverse has no synchro, and first has it only in the first/second direction. Try shifting briefly into second or third before going into first or reverse, and see if that makes the grinding disappear. Sounds to me like your clutch is not fully disengaging. Where in the stroke of the pedal does the clutch start to engage? Very low to the floor? Is the clutch master cylinder new? Bleeding the clutch successfully can take some doing. Andrew

[Andrew]

My guess is not getting full hydraulic actuation. Does the pedal pump up? Your test of holding it to the floor and seeing if the car creeps will certainly tell you if you're losing pressure, or have got air.

If it persists, I'd replace the master and the hose (the slave is new, right?) and rebleed and see where you are.

I use a one-man method, with a bleeder hose with a one-way check valve on the end, and generally get good results after a couple rounds. My cousin's 2002 took more work to bleed a new slave, but with two guys, we had it right in about an hour. Much more restricted work space.

Also make sure the slave pushrod is not punching through the TO bearing actuating arm while you're down there.

Andrew

[Gary73Super]

Pumping the clutch several times does not seem to help--at least not consistently. It seems only if I drive the car for a bit and go up and down through the gears will it then allow me to engage first and reverse without grinding, assuming I shift into first/reverse quickly enough (a stop sign or even a 30 second to 1 minute stoplight seems short enough duration to keep it from grinding so it's a slower loss of hydraulic pressure than that).

The slave is new. I've also seen that the pushrod on the slave is engaging the throwout bearing arm, although I can see after many decades how that might fail and the arm would need to be repaired/replaced.

Thanks,
Gary

Quote:

Originally Posted by Andrew My guess is not getting full hydraulic actuation. Does the pedal pump up? Your test of holding it to the floor and seeing if the car creeps will certainly tell you if you're losing pressure, or have got air. If it persists, I'd replace the master and the hose (the slave is new, right?) and rebleed and see where you are. I use a one-man method, with a bleeder hose with a one-way check valve on the end, and generally get good results after a couple rounds. My cousin's 2002 took more work to bleed a new slave, but with two guys, we had it right in about an hour. Much more restricted work space. Also make sure the slave pushrod is not punching through the TO bearing actuating arm while you're down there. Andrew

[gadwhite]

Gary
First I know nothing about the set up on the Guilia Super, or the Alfetta,
However, I had partially similar symptoms on my 85 Spider Veloce, with one other noticable symptom. At idle, in neutral, without the clutch being depressed I would hear a rattle from the bellhousing. Do you hear anything like that?

What had happened to me was the pressure plate cover had seperated form the plate itself, and finally (I think when the last spring broke) I could not get into gear from a stop. To get home I had to stop shut off the engine, engage the gear and restart the car just to get going. I do agree with the others about trying all of the hydraulic remedies first though. I replaced the slave master cyl, and the flex line and in my case a bad pivot arm ( common on Spiders). In the end though I had to pull the trans. I hope it is something simple for you, but you can view my pressure plate problem here

Gabriel

[Gary73Super]

Thanks Gabriel,

Wow, that's quite some adventure you went through! I'm sure there are no significant differences between a Super and a Spider in this area. But, I'm not hearing any noises I'd call significant when I let the clutch out in neutral. There might be a really light noise that could be called a rattle, tapping, or grinding, but I've heard that in every 10+ year old car I've owned including multiple BMWs. So, my assumption was that's several years of advance notice that the throwout bearing is going to need to be replaced and it will act up further when it's really time. It's a quiet enough sound on the Alfa that I'm not even sure at the moment that I get it and my BMWs have all been noisier. Was your symptom that subtle or did it call more attention to itself?

Gary

Quote:

Originally Posted by gadwhite Gary First I know nothing about the set up on the Guilia Super, or the Alfetta, However, I had partially similar symptoms on my 85 Spider Veloce, with one other noticable symptom. At idle, in neutral, without the clutch being depressed I would hear a rattle from the bellhousing. Do you hear anything like that? What had happened to me was the pressure plate cover had seperated form the plate itself, and finally (I think when the last spring broke) I could not get into gear form a stop. To get home I had to stop shut off the engine, engage the gear and restart the car just to get going. I do agree with the others about trying all of the hydraulic remedies first though. You can view my pressure plate problem here Gabriel

[gadwhite]

Gary
The sound was not very subtle, not grating or loud and I drove the car for several months with it. My car is an open car though so it may have been easier for me to hear it, and usually I noticed it in the garage. Keep on the Hydraulics though and if neccessary replace/rebuild everything to rule that out before you start pulling the trans. Good luck

[Gary73Super]

After being gone 3 of the past 4 weekends and the resolution of another Alfa problem taking priority last weekend, Positive Solex Experience, I'm planning to get back on this gear grinding problem this weekend.

In the limited time I've driven the Alfa over the past few weeks I haven't had any serious grinding, just more of a thunk going into first gear on occasion and then it's in. Plus, shifting into second gear before first has also helped sometimes. So, perhaps the clutch bleed that was done a few weeks ago did help the situation. I also found that I couldn't get the car to start moving forward by putting it in first gear with the clutch down and just holding the clutch down for several minutes. So, when it has pressure it seems to keep it I guess is the verdict there.

After spending more time reading about recommendations for bleeding the clutch to expel air bubbles (see Any Tricks to Bleeding the Clutch?), I'm thinking what I did before was too simplistic. I did not remove the slave cylinder from the housing nor clamp down the piston in the cylinder to keep it from moving. I just did the bleed by opening and closing the bleed valve while a helper was pushing in the clutch pedal. So it seems to me the first thing to try is this method of removing the slave cylinder and keeping the piston from moving. Is it the case that you want to hold the slave cylinder vertically (can't remember if there is enough hose to allow this) so the bleed valve is straight up? This way the bubbles would be going straight up exitting the bleed valve. Or, do you just keep the slave cylinder horizontal like it is mounted and make sure the valve itself is at the top 12 o'clock position? I'm assuming a full bleed of the system isn't necessary as that was just done and the same type of fluid will be used. If air bubbles exist, it should only take a few pushes to expel them, correct?

Then if this doesn't work perhaps the "backflush" method using a syringe is the final thing to try before concluding it's a problem with the master and/or slave cylinder.

Thanks,
Gary

[Andrew]

Normally in-place bleeding should work, with the bleeder valve toward 12. The piston may move some, but that should ordinarily matter. Often pumping the pedal a bunch of times, rapidly in succession, can bring up some pressure if your'e having trouble, but that's usually if you can't get any pedal at all, which is not the case with you. I'm at a bit of a loss.

Andrew

[Gary73Super]

Andrew,

You also asked before where the clutch engaged and I said an inch or so from the floor from my memory. After paying more attention, it's actually 2 to 3 inches from the floor which I'd consider right in the desirable range.

My mechanic friend suggested that if bleeding the system again didn't help, that perhaps the seal on the master cylinder had gone bad and was letting in air. I'd rather try the easy/cheap things first of course

Gary

Quote:

Originally Posted by Andrew Normally in-place bleeding should work, with the bleeder valve toward 12. The piston may move some, but that should ordinarily matter. Often pumping the pedal a bunch of times, rapidly in succession, can bring up some pressure if your'e having trouble, but that's usually if you can't get any pedal at all, which is not the case with you. I'm at a bit of a loss. Andrew

[Andrew]

I've rebuilt MCs and SCs that never had the same good feel as new ones, so maybe you're on the right track. It's nice to solve the probably without spending a lot of money, or just throwing money in for new parts, without knowing what was actually wrong though. On the other hand, the analytical method takes a lot longer.

Andrew

[Gary73Super]

I'm enjoying doing this level of maintenance/repair other than losing time on the road with the Alfa. Swapping carbs in and out and bleeding hydraulic lines is my current comfort level and my professional mechanic friend is my support system for having a vintage car beyond that. Fortunately this clutch issue doesn't keep me from enjoying the car so that's also why I'm not worried about the time factor. I just don't want to have it crop up if my wife wants to drive the car to work and it starts grinding in traffic at stoplights with impatient cars behind her. I don't think she'll have the same patience level (try 2nd and then into 1st, or start in 2nd gear, or turn off the car then put it in 1st and start the car in gear, all preferred to forcing it into 1st/reverse) that it requires so I want to get it to a "turnkey" state mostly for that reason. Plus everything else is so right with the car and none of the vintage cars I've owned before I could say that about in the same way.

-Gary

Quote:

Originally Posted by Andrew I've rebuilt MCs and SCs that never had the same good feel as new ones, so maybe you're on the right track. It's nice to solve the probably without spending a lot of money, or just throwing money in for new parts, without knowing what was actually wrong though. On the other hand, the analytical method takes a lot longer. Andrew

[Gary73Super]

I did the slave cylinder out bleed this weekend.

First, whomever invented snap rings has got an evil streak and whomever designed this Alfa installation is doubly sadistic Even with snap-ring pliers it was mostly an effort in futility. I thought I'd just have to take off the one ring closest to the cylinder piston rod. But then I discovered how a flange in the transmission stuck out just far enough making it impossible to slide the other snap ring by (I seriously considered using a hammer to smash that bit down and out of the way for the re-install and future maintenance, but decided to preserve the "integrity of the design", if you can call it that--either "integrity" or "design"). So that meant working one of the snap rings over the entire length of the cylinder by both mounting grooves. I did become a little better at using the pliers over the couple hours I spent underneath the car between the dismount and re-install, but still 95% of the time the ring just slips off the pliers right away until getting lucky (I was only able to find 2mm ends for the pliers at the largest where something like 3 or 4mm would probably have been the correct size). Other than that the actual bleeding of the clutch is easier than with the cylinder mounted since it can just sit on the ground vertically inside a clamp. I borrowed a clamp especially built for holding the piston of slave cylinders for BMWs and adapted it slightly for Alfas (I also noted how the instructions mentioned removing the slave cylinder for BMWs simply by loosening a couple of bolts ).

I am 100% sure there is no air in the sytem now. I wasn't paying close enough attention to the very first push of the clutch pedal so I'm not sure if bubbles came out, but I know in all succeeding pushes it was all fluid. I have yet to have the grinding in first and reverse come back, but probably a little early to declare victory.

I do occasionally get a light "thunk" now when shifting into first that is quite distinct from the gear grind. It happens so quickly and then I'm in gear and it's so much less violent sounding than the grinding gears that it doesn't feel like it could be doing any real damage, at least to anything that isn't already on its way out. It doesn't happen in normal driving, just the times when the car is idling with the clutch out for a couple minutes like when I was getting the grinding before. So, perhaps it is related to the grinding and something else related to the clutch is loose or going bad?

My thought now is just to enjoy the car and see if this behavior gets any worse in the coming months assuming the grinding doesn't come back. After this latest fluid bleeding, the car does feel more solid going into second and even third gear than it's ever felt before. Not that it was grinding giong into those gears before, but now it just seems like a brand new transmission for how clean and sure it feels. Or, maybe it's all just psychological knowing how many hours were spent on this supposed little maintenance task

Thanks,
Gary

[Andrew]

If you rotate the SC way around you get past the flange issue. The snap ring has higher and lower parts, and some clear the flange. It's not at all a friendly design, unlike most of the 105/115 chassis.

Andrew