TR8 LT77 gearbox help....

[rallypug]

I have just completed rebuilding a TR7 V8. Having driven the car for about 50 miles, I now have an issue with the gearbox. LT77) It goes easily into first gear, then, when 2nd is selected, it goes in gear (noisily) but if I pull the stick further down, it starts to 'crunch' , this is the same when i select 3rd, and again if I were to pull the stick down it starts to 'crunch'. 4th and 5th are fine. I've read a lot about crap LT 77 boxes.... So is it a case of bin it and start again ! ??

[rallypug]

Thanks for the advice. I intend to check the points you suggest at the weekend....I will let you know more then ...