280zx rolls back in drive

i have a few auto cars but the zx is the only one that rolls back on a hill when in drive ,gear 1 or 2 , but locks up fine in park, when i drove the car into the garage  from a slite angle it rolled back i drive forward then stop the car it stalls every time, any ideas?

You've either got a badly leaking valve body, or your stall convertor or auto is shagged.

there is somthing leaking there is a large patch of somthing on the floor , what is a valve body , sorry not a joke any tips?

Your leak is transmission fluid......dont drive it .....youll cook it

Firstly, Id be jacking the car up and taking a look  see where the leak is or what is loose to be draining your juice..

cheers for the info i will do that now,

There are a few items on these that are hard to find, my mate couldnt get his auto fixed, so he pulled one from a series 1 R31 Skyline, and swapped bellhousings, bolted in and all is good.

the series 2 skylines have a little computer for controlling shifts etc, not recommended.

I know of a 1979 manual conversion out here in Canberra in fairly reasonable nic... postage a bummer though

Replacement boxes aren't hard to find if you need one. Another alternative is a Z31 300ZX, with the aforementioned bellhousing swap.

But rebuilds for the 3N71B/4N71B aren't all that expensive either. I had mine tricked up with all new parts for less than $800.

(Unlike the full rebuild I've just had done on our '92 Liberty - that was $2k!)

Ben, can you provide more details on the gearbox mods?