gearbox repair manual

Hi i have broaken gearbox i need gearbox repair manual for any type of engine
THX

Hei.

What´s your car?

Morten.

Fiat 128 Sport CUpe

Finaly i determine the type of gearbox but i cant get more info about gearboxes used on ritmo/regata/strada for engine type 138 1500ccm
the type number is 138AE 2A.1
I have 2 pieces one is totaly damaged.
One is currently on car.
But she will blowout for a while.
I need repair it.
There is input - drive cramshaft in gearbox molten with gear wheels - one piece
I can replace it with other with shorter - short gearbox (cant find how to say it - if anyone dont know what i was meaninig just ask - sorry for my language i live in non EN lang. speaking country)
So if anyone have some info about 138AE engine or gearbox 138AE 2A.1
let me know
Why i can this one ?
There are dry axles 3 piece axle are without 3angle but left is on 6 bolts and right from motor side is 2 pieces. So midle part is on bolts near the wheel and that side is comming to gearbox is rim krankshaft
so bought side of gearbox have gufero.
I dont know what other types of gearboxes that are short (for good acceleration) with this mountings for 1500ccm 138 engine was maded so i dont know what else i need finding.

THANK for Any Info

Oh i forgot this one is joined from that two i have.
I was repairing it so i know what is inside.
And i was forget say that i need gearbox with bottom shifting.
Because there was 2 type of shifting for this cars.

Tanks for any info, idea ...

If anyone know some other model of 5 speed gearbox for 138 engine 1500ccm (relative short gear ratio) with bottom shifting and left side mounted with 6 screw (plate like at newer fiat models or diesel) or model of car was this used let me know tnanks.
I seriously need to repair or new gerbox.