shifter cable or clutch cable?

[e0nz]

I have an automatic 1985 Pininfarina Spider. I need some help distinguishing what part to buy for it. The automatic shifter doesn't "lock" into place and I'm concerned that it slides down gears (but not up) when I put some force into it. What needs replacing?

[maytag]

eonz:
god post, dood! Started with all the pertinent information! you're miles ahead already!

so, your auto-trans car doesn't have a clutch, so you can rule-out the clutch cable. Nor would I immediately be suspicious of the shifter cable itself.

I've never owned a Fiat with auto trans, so what I'm saying is more relative to general practicval applications than to fiat specific, but intil someone mre knowleadgeable comes along, I'll see if I can give ya something to look at. ??

The shifter moves back - n - forth (or up - n - down) through its travel in a smooth path.... what provides the positive "stop" in each gear selected is a detent (think "tooth") in the shifter mechanism itself.

Now here's where we need sme specifics from someone with a drawing: there could be an adjustment that will allow you to firm-up the detents. Or you may need to replace some consumable part of the mechanism.

[So Cal Mark]

it uses a linkage, not cable. It may be out of adjustment or worn. It does use a detent type lock on the shift handle, so it could be either adjustment or wear. Although, it would be odd to wear a steel bracket that much. If the handle is loose, it may be slipping off of the detent