I've met guys who've said the auto's are farking tough. BUT they are a bit heavier too.
The best way to operate the overdrive switch is to have a dipswitch like valiants and the lke used to use on the floor. Then when you run out of revs you just kick the dipswitch, and your in angel gear. My dad did this when he put an LD28 in his old XD work hack. It was kinda cool, like a manual kick down for overtaking on the open road.

All this talk has almost got me wanting one. Does anyone have the actual weight figures for them? My 63A box is a monster bit of kit already. (Comparable to a 56 four speed)

Peter Gilroy Automatics in Toowoomba Best I know when it comes to JATCO boxes it's worth the call.

The bellhousing of a 3n71b will bolt straight
up to a 4n71b overdrive trans definatley. It
would not matter which car it came out of
because you would have to have a
converter custom made anyway. Lock up is
not as scarry as people think and for a
highway cruiser it is an advantage, it will offer
a "deeper" overdrive and eliminates slip in the
converter with a mechanical instead of fluid
coupling therefore reducing friction and heat.
overdrive would be a manually operated
switch on the dash to energize the solenoid
and a lock up switch would be no different.
For strength a turbo vl commodore box would be ideal,
hope this helps

The Jatto 4N71B was released after the last of the B310 cars were made I believe & when I can I plan to fit one to an A15 & use them in my 1200 coupe.

They were used in a number of cars, including Skyline models & some Commodores, but I intend to use one from a 4 cylinder Pintara. These did not have the lock-up converter feature & this simplifies the instalation quite a bit as far as I can tell.
I have every reason to believe that the trans case will bolt to an A series bellhousing & use the A series torque converter, but I have not put that to the test yet.

The trans is basically a three speed with a selectable overdrive, so the advantage that it offers is in the 'highway cruising' end of the performance spectrum.

I was just reading WIKI about the auto transmission, and just wondering if the 4-speed automatics came out in Austrailia, and if so in what vehicle? sunny(310)? or 120y?
It states that the 4-speed autos came out in th 80's so i'm assuming it more than likley to be the sunny, if at all it was available.

This is how it goes. You take of reving it out in 1st then move the lever to 2nd, the box changes straight up to 2nd and you pull the lever straight back to 1st, the box won't change back to 1st untill you lock the back wheels with the hand/foot brake at the next corner, then you power away in 1st again. I guess it works a bit like a preslector box. The auto sucks alot of power though I would't think it would be much good in a road car. It works well on the dirt, dosn't wast time spinning wheels just grips and goes without wheelspin.
olboy

I have a good Jatco 3N71B complete with all the bits, Oh minus rear crosmember, for sale. If you are interested

Quote:

I think that they are in Dandenong.

The Jatco 3N71B is a good 3 speed auto trans design, but there are a couple of things to know [at least about the ones behind A series engines.]

Selecting first will lock it in low. No upshift, no way.
Selecting second will lock it in second gear. that's it, second gear.
Selecting third [Drive] allows normal function.

The normal shift point is controlled by the govornor in the back of the trans [speed related] & the vacuum modulator valve. This means that in unmodified form the trans needs to see manifold vacuum to know how much load the engine is seeing.
High vacuum, = light throttle & low load, so earlier upshift.
Low vacuum = heavy throttle & high load, so late upshift.

A turbo pumps pressure into the manifold, so a suck through design will provide a vacuum signal between the carb & turbo, but a blow through design may be a problem.

my auto behind my a14 is a slug off the mark because of the cam,
i do give it heaps thou !

TOSSER i manualy shift it and it just holds gears until you change it ......

cant wait for me to get of my ass and put the manual in it thou !!!!!