Hi all again, Sorry to be wearisome, but this is the place for knowledge. As I stated in my other post about clutches I am buying an FS5W71B 5-spd tranny w/ 50,000 miles on it. This question is should I take a peek inside to check the notorious main and countershaft nuts which like to back out causing much havoc, or should I leave well enough alone? What should I look for (if that's the advice), and what should I do to prevent the nuts from backing out?

I have to say that I have NO experience with trans missions, but am a pretty capable mechanic and can follow instructions. I have the FSM from Courtesy and the Haynes manual, also.

The owner said the tranny had been a replacement for his 78 Black Pearl which experienced the notorious shaft nut backing out and destruction of his original tranny. He recently went for an 81-83 ZX tranny and didn't need it any more. He said it worked perfectly when he took it out. Thanks for the help and advice.

Cheers, Mike

Mike, my experience with the internals of Datsun transmissions is limited to the earlier Type A four speed. But I'm certain that the guts are similar enough to say that you can't just "peek" in there. The mainshaft nut is deep inside, you'll need to completely remove the gearset from the case to check it.

If you have doubts about the bearings or synchros, sure, take it apart and deal with those, the bearings and correctly tighten the nuts when you're done. Otherwise I'd say let it be.

I would agree with Arne. Fortunately these transmissions are relatively "easy" to remove if a problem does occur.

Thanks for the replies. I'm not sure what I'll do, yet. I haven't seen the tranny. I will pick it up this weekend. I don't think I can go wrong for $100 even if it has to be rebuilt.

Cheers, Mike