Good evening. And Welcome to the forum!
Yes, the steering rack on a Fiat Uno can be repaired, depending on what’s actually causing the noise.
A nasty noise from the front left is often not the rack itself.
Much more common causes are:
Worn track rod end/inner tie rod
Lower ball joint
Top strut mount/bearing
Dry or damaged CV joint
Suspension bushings.
Before condemning the rack, jack up the front and check for play in the wheel (left–right and up–down). Listen while turning the steering with the wheels off the ground. Inspect rack gaiters for splits or leaks (if power steering).
If it is the rack, manual racks can sometimes be rebushed or adjusted. Power-assisted racks are usually not economical to rebuild unless parts are available locally.
Bottom line:
Diagnose first.
The rack is rarely the first thing to fail on a Uno.