[Roadsters] Changing transmission fluid

[Scott McGillivray]

I have a 1969 1600 with 4-speed that can use a transmission fluid change.
I've never done a trans fluid change.  I restored the car 2 years ago and
trans was the only fluid I didn't replace, so the existing is at least 15
years old.  I logged about 1000 miles in last week's scorching hot weather,
this week something under my feet occasionally rumbles on deceleration.

I'm going to check the driveshaft bolts and change the rear-diff oil, but
when it comes to the gearbox I have no clue what I'm doing... although I'm a
fast learner and I have Scott Sheeler's "Datsun Roadster Book".

- I don't see a trans dipstick, how do I check the gearbox oil level?  How
much oil should be in there?  *4speed*
- Is the filler bolt the one underneath on the driver's/left side?

Other tips are greatly appreciated... step by step instructions are
better... instructions with pictures and I'll send you a Christmas card
every year.

-Scott