jessezx

can a swap to a 4n71b be done by changing the bell housing or are the electronic connectors different and would mess with the ecm?

NismoPick

From what transmission to the 4n71b? And what car is this 4n71b from? Lastly, the 280zx ecu doesn't have any controls for or from the transmission.

jessezx

i was just shootin around some automatic options for a 280zx i figured that since the 4n71b is the same as the 3n71b in say a 1982 280zx theoretically you could change bell housings move some mounts and you would have a 4 spped automatic z right?

hoov100

the 4n7 is from the z31, which is as big of a pile of dog ****, as the s130's three speed. The best bet, would be to adapt one from a z32.

jessezx

o i see im not going to do any other auto configs cause i will be swapping to a manual in a couple years i was just curious if it had been tried and or worked

FubarI33t

since the KA engines 5 speed trany will bolt up, with a slight bore out for larger barring, only makes since it's auto will bolt up too.

lifegrddude

To the OP, here's something that was written on zcar.com a long time ago. I had it saved thinking I would try it, but I went with a manual transmission swap instead. I don't remember who wrote this article originally.

"ZX 4 speed automatic conversion
Well, here it goes: Instructions for converting your 81-83 280ZX Turbo or
Non-Turbo car to a 4 SPD (O/D) Automatic Trans:

Parts to get at your local recycler:

1-82 thru 83 Maxima A/T bellhousing (or entire trans ONLY if you are going
to install this unit into a Non-Turbo car with less than 200 HP)
1-82 thru 83 Maxima flex-plate with hardware
1-83 thru 89 Mitsubishi Starion or 84-89 300ZX TURBO ONLY! Torque
converter (these have either a 2450-2550 or 2750-2900 stall speed
converter) I used the higher stall speed unit. Remember these listed
converters are for use with a TURBO CAR ONLY, otherwise, use the 82-83
Maxima converter for normally aspirated cars!! Very important!!
1-83-89 Mits Starion A/T complete (for TURBO CARS OR HIGH HP N/A ONLY)
1-84-89 300ZX (with A/T) driveline

If converting a normally aspirated car to this 4 spd trans, it's much
simpler than doing a Turbo car. Basically, just install an 82-83 Maxima 4
spd A/T complete with flex-plate into you 280ZX. Use the 300ZX A/T
driveshaft (you will have to have it shortened slightly). Be sure to have
your trans tested or looked at by a trans specialist before installation,
as this work takes lot's of time and early failure is sure to cause deep
depression..... Ok Turbo guys (mine is a Turbo): Get the Maxima A/T trans
bellhousing and flex-plate handy. Remove the bellhousing from the Starion
trans and trash it(be sure to only remove the bellhousing and NOT the O/D
unit!!) Whoops! Forgot, be sure to unhook the line from the bellhousing
before doing the bellhousing swap! Install the Maxima bellhousing.

Be sure to ensure that the o ring between the bellhousing and trans stays
in its place during installaition. Now reconnect the line to the
bellhousing. Install the MAXIMA flex plate (be sure that it is in the
proper direction (look for the old bolt marks, they must face the front of
the engine!!) Get the torque converter that you will use for your
application and install in A/T. Be certain that the coverter is fully
seated or serious damage will occur!! Connect the two wires that you
disconnected from your old trans to the "kickdown-solenoid." This is the
the solenoid on the driver's side of the trans (there are TWO on the 4SPD
A/T) connect the wire to the one towards the rear. Now, mount a switch
somewhere by the A/T shifter (this will be the O/D switch).

Now, find a (when ignition is on) 12 volt power source and run through the
switch. Now run power to the front solenoid on the trans (when 12 volts is
applied, the OD is OFF) Absence of voltage allows the O/D to kick on!!
Now, you are probably wandering, how do I mount the rear of the trans to
the car, well this is the hard part.

Before installation, you must cut away the old mounts that were spot
welded to the car to hold the old 3spd A/T, or 5spd.. This is essential as
the O/D Trans is 6-8" longer than your original trans. After cutting away
the above, bolt the trans to the engine (make sure that you installed the
MAXIMA flex plate as the 3spd A/T one will not work with the O/D trans!!!!
Then raise the back of the trans up and this will help you figure out
where the rear of the trans will mount to the tunnel. Now, I'll tell you
how I jumped over this next obstacle: I used the original crossmember from
the old A/T and bolted it to the underside of the O/D extension housing,
then made brackets out of very heavy steel and then fastened to the tunnel
with 4 large grade 8 bolts

Once you have made up your brackets, attach to the crossmember then raise
the trans up until the brackets contact the tunnel. Now, mark where the
brackets go with a large black marker. Drill holes through the brackets
and through the tunnel (use at least 4 heavy bolts on each side and
install a heavy steel plate on the other side of the tunnel (passenger
compartment) to help further strenghthen your installation-very important,
you do not want this install to fail!!!!! Now once mounted, you should now
install the driveline that has been shortened. Once installed, now it is
highly recommended that you adjust the driveline angle to be straight and
level-important for u joint life and minimal vibration!!!! Now, get in
that car and go to the exhaust shop, that guy will be earning his money
making the pipe clear!!

I had the exhaust shop run 3" pipe front to back, but I must tell you, it
runs very close to the frame rail and trans!!! (in fact so close, that I
wrapped my exhaust near those areas with an a non-asbestos fabric to
shield those areas from the heat. (I really recommend 2-1/2" pipe
instead-much easier....

I forgot to explain getting the proper driveline angle. I used pieces of
cut sheet-metal placed between the crossmember and the trans extension
housing as you cannot do it any other way!!! Enjoy your 70 mph cruises at
2450 rpm and 80 mph cuises at 2850 rpm!!! The trans will downshift into
3rd gear at any speed that I have tried!!! I gives quite the kick in the
Turbo car!!"

jessezx

o i see thats pretty interesting, well i am only curious cause im in an automatic tranny class and am going to rebuild my auto and run it until i swap to manual and i found a junkyard that has 4n71b transmissions and wondered about those