Been having a clutch conundrum. Every time I adjust it it works fine for half an hour, then worsens until eventually dragging with the pedal fully pressed on the floor so as I can't cleanly engage a gear.
I'm going to change the cable and suspect that is the major issue (it's probably the original...). However, when I replaced the driveshafts a while ago, I noticed the clutch lever only had one plastic bush fitted in the upper position - you all spotted that in the photo didn't you?.
The lower position isn't big enough to take a bush and the lever shaft was a reasonable fit in the casing so that's how it went back together. Anyway, I need to replace a driveshaft boot as well and so thought I'd whip the engine out to give everything a check over (I replaced crank seals etc - seems dry now ) and have another look at the clutch.
So, whilst there's not a load of slop, I'm inclined to get a 19mm drill and open up the lower position, the challenge being to keep the alignment, easier if i can find a drill long enough to use the top bore as a pilot.
Anyone seen this before? None of the usual suppliers have. The other option is to source a replacement Bell housing but that seems a bit extreme. All a bit odd....
If anyone has a long 19mm drill you might lend me I'd be very grateful too!

My personal opinion with regard to this problem is:---purchase a set of new bushes, find a local machine shop and get them to open up the casting to allow for the (correct) fitment of both bushes. When you come to refit the clutch release arm and pivot rod, don't forget to make sure that the bolt is tight (and possibly with a little bit of loc-tite)---from personal experience I can assure you,it is a pain in the arse if the bolt comes out (or breaks)--it is an engine out job all over again. :bang:

All very interesting as I have never seen a 500 or a 126 bell housing with that single top bush on the release arm. I wonder if your gearbox is a very late 126 box and this was a mod for economy. Most of the forces taken on that shaft would be on the top bush.
The other aspect of interest to me is that I built a complete nut a bolt build 650 on a 500 crankcase engine along with a similar build with a syncro 126 gearbox with a 500 bell housing. The engine runs very well, the gearbox is smooth but when I drove the car for about 12-15 miles and it was nicely warmed up the clutch ceased to work and would not allow gear changes. Let it cool down and you were back to square one. I have not stripped it out to see if I can spot anything yet but interested to see if reach any conclusions

Thanks for the replies. Funny one isn't it.
Re the bush I'm going to try to open out the lower hole in situ and pop in another bush.
Clutch wise, the adjustment, once it's moved doesn't return when cold hence I suspected the cable and/or the mounting bracket. I'll give it all a good check. It worked ok before I replaced the clutch in the springtime.
The box is off a 500r non synchro so nothing unusual. Given its one of the last 3000 made in sicily it wouldn't surprise me if it was a Friday afternoon job and just got built with presumably missed machining operation

Have you got a lock nut on the cable adjuster? before I fitted one on mine the adjuster would continually slacken.

Drilled and Bush fitted, bolt fitted with loctite 648. Sorted. 19 jobber drill was just the right length luckily.
Cable had a lock nut hence I suspect the cable. Will whip it off and see next.