You gentlemen have posed some very astute and relevant questions, to which I have few certain answers. My overall naivety is so great that I started a thread in the "builds" section of this forum; look for my topic about my 1995 high-roof cargo van 2.5Di, and I have gone into more detail there (but alas no answers there, only here.
). So, I will thank you for your current answers and future answers.
How do I know the clutch is bad? That is a very crucial question. I don't. However, I bought the van from a farming family (flower growers) who'd had it for nearly 20 years in their possession - the van's whole life in Poland, having been imported from France when it was a few years old. So, the maintenance history is unknown but we can assume that this family treated it consistently over those 2 decades. Which can be good or bad. The van never left their sight, and is not wrecked or dented; it was even garaged. Oil and filters were changed with unknown regularity but when I bought it, the filter was almost new and the oil still held viscosity and didn't smell bad, nor were there any metal shavings or anything. After changing the the oil and filter, and flushing the radiator 4 times, it runs, even purrs like a kitten. Or panther. Not sure. Sounds great, a diesel mechanic told me. What I can gather from this is that the family changed oil regularly but neglected everything else. I changed the transmission fluid yesterday; it looks and smells as if it were 25 years old, but again, no metal shavings or anything. So my main charge is that the family neglected scheduled maintenance of the van.
Now, getting to the clutch issue. When I bought it, the owner explained to me that "these vans" are "that way" when it comes to pedal feel. The pedal engaged the clutch way low, near the floor. He said that was normal. Additionally, first gear was always hard to engage; it took a hard push or multiple pushes to get the shifter into position, even with the pedal down. It has been about 500 miles since then and the pedal feel got increasingly worse, until the cable snapped. After replacing the cable and adjusting it halfway up, everything seemed to be normal except that first gear was still hard to engage. I finished my journey of 200 miles that day last week, and by the end of the journey I was noticing that the shifter was getting harder and harder to engage. Yesterday I took my son on a short trip and by the time I got home, I couldn't engage any forward or reverse gear without shutting off the engine and starting it in gear. I barely got the van parked back on my concrete pad. Do these symptoms sound like a worn out clutch? The cable is still intact and doesn't seem to be damaged or strained, and pedal feel seems good with the clutch pedal if I"m not trying to put the shifter into position. The mechanic helping me with the cable last week asked if the clutch was good. I said it had been engaging. Now it's not. If this is not a completely worn-out clutch, I don't know what else could be causing the problem. Also, the mechanic who was helping me also noted that the fork (or arm) that disengages the clutch had been damaged or repaired in some way, but when I looked at it yesterday (through the access hole), I didn't notice that the clutch cable link was not attached properly. Everything looks fine. But I will try to take it all apart and see if that is operating properly or causing any issues. I don't think so. However, I shall buy a used fork online just to be sure.
oh, about "slipping" or "jerking" of the clutch when releasing it - yes, I was getting some kind of feeling like jerking or grinding, hopping almost as it engaged. This is my first and only diesel I've ever worked on, and diesel engines have different characteristics than gas engines, correct? One thing I noticed was that I was not able to engage the gears without the clutch (while driving), as I can and have done with ease on every gas (petrol) engine I've ever had to do that to (many of them! some even for months due to lack of funds to replace them)!! So why is it that I can operate a manual-transmission coupled to a gas engine with ease (no clutch) but can't even make one gear shift with a diesel engine?