automatic to manual changeover

[keri]

Hi to you all my Gamma is still not playing after sorting the  cylinder heads it was time for a drive in fact the first drive since owning her which is over 3 years now, anyway i was aware of the auto gearbox reputation so i gave it a go and guess what it was a disaster,  in D drive it stays in one gear seems like first or second then when i manually move lever to position 3 it changes up one gear not down but does nothing when selecting 2 so been playing with adjustments to linkage but still does not change up when in D but only tested  jacked up not on road yet ran out of time  but from 2/3 it manually shifts up but doesnt seem to select 4th,      R  is ok so not sure if box is U/S i do have another auto box that came with the car but its condition is unknown, also i have a manual box, pedal box clutch flywheel etc from a scrap car i dismantled so was thinking do i just install a manual and be done with it? also are drive shafts etc the same is the changeover from auto to manual  straight forward? or should i install the unknown auto and hope for the best it seems most autos are now manuals anyway, but i would like it to  to be an automatic but  then again they are difficult to repair when they go wrong it seems nobody can repair them so i need some inspiration any thoughts?
thanks for reading my rant.

[Theo]

Midland Automatic Transmissions Ltd http://automaticgearbox.co.uk/ specialise on the repair of AP automatic gearboxes and have some parts for the Lancia versions. The AP automatic transmission is very nice when it works properly (I have an auto box in my Trevi). The most common fault is old fluid. Drain the gearbox and refill with fresh Dexron II ATF (https://www.ebay.co.uk/itm/303141907206). Don't use anything newer and thinner such as Dexron IV even though people will tell you it's compatible. Run the auto box for a while, then drain and refill with fresh Dexron II. Repeat this 3 or 4 times and you might find that it starts to work.   

[keri]

Thanks Theo will give it a go