Technical crunching gears when changing up

fiat500 · Apr 19, 2019

Fayray said:
Ok, I know this was a while ago but the problem still isn't fixed. I adjusted the clutch but ran out of thread on the cable so I added a spacer to give more adjustment. But then I found I didn't have the required free play at the top of the pedal and I'm still getting crunchy changes.

In my experience the several types of clutch component are interchangeable, at least between the "F/L" era and the "126" even though they can look very different from each other but a faulty clutch-plate could be implicated.

What you are experiencing may be the clutch actuating fork which could include it being loose on its pivot-shaft, the nylon bushings being missing or badly worn or a fault with the thrust-bearing.

It sounds like the gear-changing mechanism is trying to do its job so doesn't immediately come under suspicion but there might be issues inside the gearbox, particularly with the selector forks.

In the first instance I would disconnect the clutch-cable and return-spring and move the actuating-lever manually. There should be easy movement and then a definite stop as the thrust contacts the pressure-plate. You will be able to wiggle the lever and feel for any significant play

Fayray · Apr 19, 2019

Thanks for that. I did try to move the lever when I had the cable disconnected and couldn't move it by hand. Admittedly I didn't try very hard so I'll have another crack. When I slackened off the cable to get the required pedal free-play the return spring didn't have enough tension to return the pedal properly. The spring seems fine and I wouldn't want to have to connect it if it required too much more tension.

So it sounds like the engine and box should come out for closer inspection of the clutch?

fiat500 · Apr 19, 2019

Fayray said:
Thanks for that. I did try to move the lever when I had the cable disconnected and couldn't move it by hand. Admittedly I didn't try very hard so I'll have another crack. When I slackened off the cable to get the required pedal free-play the return spring didn't have enough tension to return the pedal properly. The spring seems fine and I wouldn't want to have to connect it if it required too much more tension.

So it sounds like the engine and box should come out for closer inspection of the clutch?

Obviously, with the spring still attached you would struggle.

It's not a difficult spring to refit. But if it can't even pull the pedal back there's either something wrong with it or the internals of the cable are sticking or frayed inside or there are issues around the clutch components.

Is the clutch cable properly secured to the side of the gearbox? I wouldn't rush to remove the gearbox until you have exhausted all other external possibilities, Depending on how long you've had the car and whether you know what has been replaced and when, it possibly wouldn't hurt to replace the clutch cable first.

Fayray · Apr 19, 2019

fiat500 said:
Obviously, with the spring still attached you would struggle. It's not a difficult spring to refit. But if it can't even pull the pedal back there's either something wrong with it or the internals of the cable are sticking or frayed inside or there are issues around the clutch components.

Is the clutch cable properly secured to the side of the gearbox? I wouldn't rush to remove the gearbox until you have exhausted all other external possibilities, Depending on how long you've had the car and whether you know what has been replaced and when, it possibly wouldn't hurt to replace the clutch cable first.

Sorry, I should've clarified that I had removed the spring as well. I'll climb under and have another poke around and check the cable is attached to the side of the box. The clutch pedal, when adjusted right up, feels smooth and springs back nicely. When I backed off the cable adjustment in search of free-play it felt very under-tensioned. So now I have about 10mm free-play (free-play being the pedal at rest to the point you feel resistance when pressing down, correct?). The bite point for when the clutch disengages is a lot higher than the 500D I drove which disengaged at about 1 or 2cm. Is this an adjustment or a sign of clutch wear?

As bad as I've made it sound it is perfectly drive-able and had i not driven the D I would've probably lived with it. That D has become my benchmark. The brakes are next; they didn't compare well either:shakehead:

I appreciate the help too

Fayray · Apr 20, 2019

update: I realised that after the last bout of adjustment, where I'd gone too far the other way to get the pedal free-play and lost the pedal tension, I put the car back on stands for what felt like the 38th time (but was probably the 6th) and adjusted it back and then put the car away without driving it. So today I went for a decent drive around town and found that I could change with less crunching than before if I was very gentle. There is virtually no free-play though.

fiat500 · Apr 20, 2019

Fayray said:
update: I realised that after the last bout of adjustment, where I'd gone too far the other way to get the pedal free-play and lost the pedal tension, I put the car back on stands for what felt like the 38th time (but was probably the 6th) and adjusted it back and then put the car away without driving it. So today I went for a decent drive around town and found that I could change with less crunching than before if I was very gentle. There is virtually no free-play though.

A useful feature of this car is the triangular cover-plate under the clutch housing which is secured with three screws. With it removed you can see a lot of what is going on. You will see if the linings are very thin which might explain why you have so much wasted pedal-travel. With the cable slackened and the spring removed you can also understand the principle of where the small amount of free-play at the pedal comes from; it's simply that the release-bearing mustn't be pressing on the pressure-plate all of the time. In practise this means that as long as the return-spring is holding it a few mm. off the plate, you will have maximum possible movement at the pedal and a reasonably high "bite"point.
A clear image with the plate removed would be helpful.

Fayray · Apr 20, 2019

thanks Peter, I will do that

Fayray · Apr 21, 2019

Here are some photos. I'm not really too sure what I'm looking at and when I got a lovely assistant to operate the pedal I couldn't detect any visual change when I adjusted the cable. I have left the car in the air with the cover off if more photos would help

fiat500 · Apr 21, 2019

Fayray said:
Here are some photos. I'm not really too sure what I'm looking at and when I got a lovely assistant to operate the pedal I couldn't detect any visual change when I adjusted the cable. I have left the car in the air with the cover off if more photos would help

It's very hard to make anything out from those. I'm trying to see how thick the two faces of friction material are. When your glamorous assistant pressed the pedal you should have seen the thrust bearing move forward and cause movement on the pressure plate. I'll look for some images if my own.

Bleeding Knuckles · Apr 21, 2019

Hi Andrew, just a thought, but is the flexible joint between the gear selector shaft and the gearbox selector input in good condition??? sometimes the rubber join can become contaminated and then it will only partially select a gear??? What is the milage on the car?? has the box been off before??
Ian.

Fayray · Apr 21, 2019

Peter, I tried to catch all the angles but the phone was so close to my face I couldn't tell if it was even in focus. My eyes sure weren't. Yes I could see the thrust bearing pushing against the pressure plate but couldn't see any separation with the pedal at rest, even if I slackened the cable right off and disconnected the spring. But I'm not sure if i should've.

Ian, I'll have a look. I've owned the car for a couple of years and there wasn't any history with the car. It's done quite a few miles so assume the box has been out in its lifetime but can't say for sure. It is selecting gears fine but just crunching as they go in, more so when it gets hot. It's not terrible, and it's perfectly driveable, it's just now I've driven a well sorted example I know it's not as good as it should be.

the hobbler · Apr 21, 2019

A number of people have put forward some very sensible suggestions to try and diagnose your problem,which is always difficult from a distance. So I would suggest the following. At the moment let us assume that the parts IN the clutch assembly are correct. There is a possibility. as suggested by Peter, that a Giardy clutch cable might be the cause (something that he had come across before). As the Giardy is 4ins longer than the saloon, this is a possible cause. So, ignore what IS fitted at the moment, and get a new SALOON clutch cable fitted. I would then suggest that you drain the gear-box oil and fill it with fresh oil. The 'Factory' specification for the gear-box oil is a "SAE 90" oil. There is a number of gear-box oils made by a specialist oil Company called "Red-line" which seems to have a good reputation for rectifying noisy/difficult-to-change- gear, gearboxes----one of their products is a 75W/90 gear oil. Might be worthwhile trying that if you can get hold of it in 'up-side down land'. Keep asking the questions, we will keep trying to come up with the answers and when the problem is rectified we will all have learnt something.

Fayray · Apr 21, 2019

the hobbler said:
A number of people have put forward some very sensible suggestions to try and diagnose your problem,which is always difficult from a distance. So I would suggest the following. At the moment let us assume that the parts IN the clutch assembly are correct. There is a possibility. as suggested by Peter, that a Giardy clutch cable might be the cause (something that he had come across before). As the Giardy is 4ins longer than the saloon, this is a possible cause. So, ignore what IS fitted at the moment, and get a new SALOON clutch cable fitted. I would then suggest that you drain the gear-box oil and fill it with fresh oil. The 'Factory' specification for the gear-box oil is a "SAE 90" oil. There is a number of gear-box oils made by a specialist oil Company called "Red-line" which seems to have a good reputation for rectifying noisy/difficult-to-change- gear, gearboxes----one of their products is a 75W/90 gear oil. Might be worthwhile trying that if you can get hold of it in 'up-side down land'. Keep asking the questions, we will keep trying to come up with the answers and when the problem is rectified we will all have learnt something.

Thanks Hobbler, it sure is difficult from a distance and I appreciate the efforts.
I'll look into getting a new saloon cable but if the cable fitted was correct is there another reason that it would need to be adjusted beyond its normal range? Would a worn out friction plate affect this?
Is the cable relatively straight forward to replace or will I need to be a contortionist with the patience of a saint?

I changed the gearbox oil and this did help a bit but there does seem to be a few leaks under the car that I can't locate the source of. I assumed the oil was coming from a leaking sump gasket but there may be some coming from the transmission I suppose. I managed to remove the fill plug without issue when I did this but I can't get it out now to top it up, which is frustrating

fiat500 · Apr 21, 2019

Fayray said:
I'll look into getting a new saloon cable but if the cable fitted was correct is there another reason that it would need to be adjusted beyond its normal range? Would a worn out friction plate affect this?
Is the cable relatively straight forward to replace or will I need to be a contortionist with the patience of a saint?

The cable on my car that I have fitted using spacers to cover the extended thread has worked well for four and a half years.

The reason why the cable is adjustable and why modern cars have self-adjusters is that when the friction material wears down, the pressure-plate has to move inwards towards the flywheel to accommodate this. Consequently the release-bearing has to be adjusted closer to the collar on the pressure-plate; which is what you are doing when you wind in the adjuster-nut. There comes a point when the friction plate is so worn that the geometry of the release lever will not accommodate the extreme angle of movement needed to put sufficient force on the pressure-plate to completely disengage the friction material. This will cause drag which effectively means that you are trying to change gear whilst the clutch is half-engaged. This may not be your problem (as suggested in previous posts) but as your problem as reported centres around the cable, that's the area that seemed to require thought.

If your clutch is entering this zone of wear I would also be expecting you to experience clutch-slip when taking on steep hils or when setting-off from standstill; so many other possibilities exist for the cause of the issue:bang:

Fitting a new cable isn't that bad.

Fayray · Apr 22, 2019

fiat500 said:
The cable on my car that I have fitted using spacers to cover the extended thread has worked well for four and a half years.

The reason why the cable is adjustable and why modern cars have self-adjusters is that when the friction material wears down, the pressure-plate has to move inwards towards the flywheel to accommodate this. Consequently the release-bearing has to be adjusted closer to the collar on the pressure-plate; which is what you are doing when you wind in the adjuster-nut. There comes a point when the friction plate is so worn that the geometry of the release lever will not accommodate the extreme angle of movement needed to put sufficient force on the pressure-plate to completely disengage the friction material. This will cause drag which effectively means that you are trying to change gear whilst the clutch is half-engaged. This may not be your problem (as suggested in previous posts) but as your problem as reported centres around the cable, that's the area that seemed to require thought.

If your clutch is entering this zone of wear I would also be expecting you to experience clutch-slip when taking on steep hils or when setting-off from standstill; so many other possibilities exist for the cause of the issue:bang:

Fitting a new cable isn't that bad.

Thanks Peter, the last thing I want to do is cause you guys even more frustration than I'm experiencing

.

I'm not getting any clutch slip so probably not the friction plate then. I also checked the cable was mounted to the side of the gearbox, which it is.

I think what I might do is take it to someone who understands these things better than me and have them experience the problem first hand, see if anything jumps out to them. Either that or you'll be getting a video next

the hobbler · Apr 22, 2019

Morning Andrew;
As Peter said, fitting a new clutch cable isn't that bad a job, just a bit of a faff. His description of the clutch/release-bearing operation was very clear. However, we have got to the point where we have got to know exactly what you have on the car in order that we can eliminate the faulty/incorrect part and rectify the problem; hence my suggestion to fit a correct specification clutch cable. It MIGHT not cure the problem, but at least we will have eliminated that as a probable cause and can move on from there.

gordinir8 · Apr 22, 2019

Let me put this on the table. My 126 gearbox always was crunchy at first gear. To make a looong story of adjustments and car jacking short, I discovered that the clutch pedal was secured in the clutch shaft with a nail instead of the thicker original pin so the travel of my clutch was limited! So I made a new pin that fits there tight and I gain full travel. Now first gear is dead easy to put but also gearbox operation is even smoother.

Fayray · Apr 22, 2019

the hobbler said:
Morning Andrew;
As Peter said, fitting a new clutch cable isn't that bad a job, just a bit of a faff. His description of the clutch/release-bearing operation was very clear. However, we have got to the point where we have got to know exactly what you have on the car in order that we can eliminate the faulty/incorrect part and rectify the problem; hence my suggestion to fit a correct specification clutch cable. It MIGHT not cure the problem, but at least we will have eliminated that as a probable cause and can move on from there.

That is what I will do. Will order one today. Thanks.

gordinir8 - I haven't looked at the pedal end so I'll check. Thanks

Fayray · Apr 23, 2019

fiat500 said:
If your clutch is entering this zone of wear I would also be expecting you to experience clutch-slip when taking on steep hils or when setting-off from standstill; so many other possibilities exist for the cause of the issue:bang:

Fitting a new cable isn't that bad.

Was idly reading my Autopress manual and saw this (point 2) which suggests the friction material could be well worn down without causing slip. So if I understand this correctly (and I know that's a stretch) my clutch driven plate could be worn out causing the the cable adjustment to use up all its available thread (and then some). Is it possible then that this is causing some crunching if the clutch can't fully disengage?

fiat500 · Apr 23, 2019

Fayray said:
Was idly reading my Autopress manual and saw this (point 2) which suggests the friction material could be well worn down without causing slip. So if I understand this correctly (and I know that's a stretch) my clutch driven plate could be worn out causing the the cable adjustment to use up all its available thread (and then some). Is it possible then that this is causing some crunching if the clutch can't fully disengage?

"idly reading"!...I like your style Andrew!.

Yes..that's one of the surmises I am making. I can't easily find the data which gives the new lining material thickness of the clutch but I guess it would be anything up to about 4 to 5mm. So if it was down to 1 to 1.5mm it would be ready for changing in any case; someone must have the correct wear-limits.

You could get a measure of this if you have any plastic spacers handy that you could place against what you can see from underneath; I use these things when involved in DIY work and they come in all the basic mm sizes.

Ultimately a very worn friction-plate will slip, but the operation of the diaphragm-spring accommodates this for a long time.

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