My '75 occasionally grinds when I drop it into 1st at a complete stop. It usually happens after being driven at highway speeds. It also is sometimes difficult to get it into 1st from a complete stop (almost always when I'm the lead person a stoplight). I have a Rennshifter installed and the firewall bushing has been replaced recently, so I don't think it's in the linkage. Transmission fluid was recently changed. Is it time for tranny rebuild or is this just the finicky nature of the beast?

Mine does exactly the same thing, I thought it was normal from what I have read..

I always drop it in first while rolling to a stop. No problems!

Either weak 1st synchro, clutch release bearing, or maladjusted clutch pedal movement. It could also be the oil used in the box. In my experience with the 901 box, the 1st synchro tends to be weak, and I would usually put the car in 1st while still slightly moving and leave the clutch in while at a stoplight / sign.

If it's like most trannys, I always go to second before trying for first. Gets the cluster spinning at a more appropriate speed...

OK thanks. I replaced the clutch release bearing when I rebuilt the engine. Could be the clutch pedal adjustment though. Will check that out.

My 75 1.8 FI has no 1st gear (popping out when releasing the clutch pedal which I know has a synchro issue) since 2011 but I still drive my car using 2nd gear. But the issue you have has the same thing with my 2nd gear from full stop, so I also put into 2nd gear while rolling before a full stop. And yes no problem except giving so much force with our clutch tube (although I already repaired my clutch tube last year).

Just sharing also.